wI0OK /r Glen Arbor - Empire Repeater Blog

Assorted mods & mtce

2007-07-20T23:39:00.000-04:00

Greetings,

Today I spent about five hours working on the repeater tending to an eclectic assortment of items. Some related to the new controller installation, others that would fall under 'routine maintenance'.

I checked both the main and secondary receivers for both the 444.725 and 52.92 repeaters and found all four to be of normal sensitivity and without noticeable transmitter desense.

The Six meter Voter (an LDG unit) was checked and found to be favoring RX-3 (100' up the tower) over RX-1 (330' up the tower) by a fairly wide margin. This was corrected and the alignment of the RX-2 (the receiver located at the W8TVC location) was brought more into calibration. Hopefully the system will vote properly for the receiver with the best signal.

The DStar 145.36 repeater duplexer tuning was inspected and found to be 'on the money'. The RG213 coax jumpers from the duplexer to the DStar repeater were replaced with equivalent lengths of 1/2" superflex heliax and after measuring there were modest improvements with the better coax.

While on the topic of DStar, late in the evening on 7/19 it was noticed that the DStar repeater was off the air. On arrival at the site about 11:30am today I found the physical appearance of the system to be normal. The DStar repeater came back to life after power cycling. Power cycling of the DStar system is possible remotely via the 'FCC Legal' control system-- I should have thought to do that on Thursday night--- and save having the system offline for so long.

Hopefully, the apparent 'crash' of the DStar internal computer does not become a routine occurrence.

I opened up the new RC210 controller chassis and installed a hex buffer from two sections of a CD4049 in line with the COS signal from the six meter voter. This should improve operation of the switching circuits as the logic level was a bit marginal due to the high source impedance combined with a low load impedance. This brings into match the wiring of both the wI0OK/r and W8TVC/r controler chassis.

I attempted to upload the 'quack5.wav' file in order to reinstate the old DTMF test from the previous RC210 and the DVR (Digital Voice Recorder) in the controller but it did not play out. I tested the DVR with a local recording via RF and it does function. Perhaps the encoding of the WAV file required by the newer RC210 is different from the older versions.

Thankfully, the DTMF decoding of this new RC210 appears to still be functioning. I'm still crossing my fingers that the intermittant open trace on the board has been eradicated. I did notice that from my SyntorX certain DTMF tones from 6m were not decoded. All tones decoded properly from my Yaesu VX7, so it looks as if I may need to tweak the audio equalization at some point (most likely the culprit is the 'new' PL filter in the new RC210 chassis-- this filter is derived from an RCA700 radio, whereas the older chassis used a filter from a Motorola Motrac).

I also verified the reception sensitivity of the 440.05 link setup and found that the receiver had adequate sensitivity but that there was excessive loss (about 10db) in the duplexer (the 440.05 receiver is fed from a Cellwave Stationmaster at 100' and the RF is split with the control receiver and the 3rd 449.725 receiver via the duplexer.) I will replace this 'mobile' duplexer with a different unit later this year, hopefully providing a greater fade margin for the link from the W8TVC/r system.

Sadly, I neglected to verify that the transmitters and receivers were on frequency--- oops. while it's simple to verify the transmitters (I can do that from home), the receiver adjustments require a visit to the site. These adjustments will be tended to soon, on a 'seasonally cool' day. Today would have been a perfect day, but alas-- I didn't give frequency drift a second thought. Harumph. For the most part, the radios appear to be functioning properly, but there is a question as to whether the link from Empire to W8TVC/r is properly netted on frequency--- it sounds about 5khz off at times. It's been about two years since the frequencies were netted.

More news as it happens--- or within six days.. ahem....

73
John KF8KK

Repeater Controller Upgrade News

2007-07-17T19:36:00.000-04:00

Greetings,

Yesterday and today the new Arcom RC210 controller for the GlenArbor / Empire repeaters was brought to the site and installed.

Sadly, it appears that the DTMF decoding problem which caused the RC210 board to be shipped back to the factory has developed the same problem again. After a bit of investigation I have concluded that this intermittant problem is due to either a cracked trace on the board or a bad IC socket. Pushing on the board in certain ways tends to change the failure mode.

At times the board would only detect DTMF '123' to call up the time, other times it would not decode any of the 'even' digits. Sometimes it would decode on 440, but not on six meters.

The last work on this problem was my replacing the IC sockets for the DTMF decoders. The RC210 has NOT failed since that work, but it is too early to tell as the problem was intermittant. I am encouraged, however. Any additional failure due to this problem will cause me to purchase yet another RC210 in hopes to finally get a good one (note that the RC210 put in service at W8TVC/r appears to be good--- this RC210 for Empire is meant to replace an RC210 built from a kit in 2003 that has some wierdities).

Otherwise, at this point MOST of the functionality that the repeaters had has been returned. The 'quack' DTMF tests are not operational yet (I need to find that quack file!).

Additionally, certain two meter remote base frequencies are not available, as is the VFO mode of the remote base. The 147.04 and 146.78 (the two frequencies most used) are functional. Apparently the frequency data to program the Motorola SyntorX is not satisfactory to the unit. Investigation of this problem will be taken up later in the year. The VFO mode (and the memory channels that rely on its operation) are almost totally unused and time is at a premium right now.

The 224.56 remote base, and the Weather Radio are also functional. Readback of A/C and battery power at the site also works.

This new controller is set to pass all DTMF tones. No longer is it necessary to hit '555' to unmute the dtmf. This is in preparation for the new Echolink DTMF decoder to be installed at the W8TVC/r site later this week. The plan is to eventually make it easy to command the Echolink node via 444.725 and 52.92.

While this new controller sports an interface to eventually connect to the 145.36 wI0OK-HD DStar digital voice repeater, that machine is not yet linked in. The linking of the digital repeater to the analog is slated for late fall. Sadly, there are interesting issues that must be addressed with circuitry in order for the link to function as one would expect. An example is that DStar users can send data through the repeater seperately from the audio. The interface must know to ignore the data-only transmissions of the repeater, otherwise it would seem as if there are many 'dead carrier' keyups from the DStar realm making for an annoyance in the analog world.

Overall operation of the new controller should be identical to it's predecessor. I will be publishing a newly revised 'Cheat Sheet' shortly.

73
John KF8KK

W8TVC/r controller upgrade update

2007-07-13T10:59:00.000-04:00

Greetings!

Last evening more time was spent at the W8TVC/r repeater in order to finalize the controller installation. While the job is still unfinished, good progress was made.

The Echolink node interface (the computer side) was replaced, and additionally some circuit modifications were made to the controller side that communicates with the node. Apparently the 'phantom' COS signals were related to the PL Encode signals and the logic had to be rerouted somewhat for proper operation.

In addition, some capacitors were changed in the audio of the Echolink PC feed to the RF gear to provide additional high-frequency response (the Echolink audio sounded a tad 'muddy' previously).

An audio rolloff circuit was added to the outpu of the 144.67 receiver to bring the response of that into a more acceptable range.

Finally, an older multiport serial card was added to the Echolink pc in hopes of adding more serial ports (needed for the new Echolink DTMF decoder and the RC210 remote control software). Sadly, this older 'legacy' ISA board was not immediately recognized by the computer and the 'cheat sheet' which had the information on how the boards jumpers were set (and needed to manually tell the computer where the ports were) was elusive at the time. Being near 11pm at the time, Dave and I called it a day.

73, KF8KK

Empire Controller Upgrade Project Commences

2007-07-01T22:34:00.000-04:00

Greetings,

Yesterday, June 30, the first outage associated with the upgrade/replacement of the RC210 controller took effect.

Part of this project is the replacement of the old 'kk standard' three pin molex/nylon power connectors with the standard 30amp Anderson PowerPole connectors. During both Saturday 6/30 and Sunday 7/1 the power connectors were replaced.

On 6/30 the 'FCC Legal Controller' chassis was temporarily removed in order for some minor modifications to be implemented. These mods deal with the new DStar system and the current packet configuration on that site. Additionally, certain wiring was removed as it was no longer needed due to the added voting system that was put in service after this module was created. The revised controller chassis was placed in service on 7/1 and appears to function well. It now awaits the installation of the new, revised RC210 chassis.

Sadly, on 6/28, the new Arcom RC210 controller was shipped back to the factory due to a very strange problem (infant mortality) wherin it would not accept commands from port-1.

With the new 'FCC Legal Controller' mods in place, the new Anderson PowerPoles in place, and the new chassis for the RC210 fully wired, the controller update project is nearly complete. The DStar interlink is a seperate project which did require the added functionality included with this controller update in order to be interfaced. I expect the DStar project to be implemented in the early fall (there's a host of 'interesting gotchas' that get involved in recovering an accurate COS signal from the received DStar signal)(ahem-- and the IC2200h linking radio is too nice next to my easy chair!).

In other, somewhat related news, the new Echolink interface board (the part that mounts in the pc) for the W8TVC/r system has been laid out and needs to be etched. This board will be a multi-purpose board that can also be used to provide switching and delays that are often needed in interfacing the links (see the fix for the echoey feedback in a prior post).

It was also discovered that it appears the 'phantom cos' that was being fed to the Echolink PC was most likely related to the 'courtesy tone with ctcss' mode that the W8TVC port-1 output is configured. The CTCSS driver also feeds the Echolink PC as COS, and hence, it was adding an undesireable signal to the system. I have worked out a minor circuit change to fix this (the fix will also help with the DStar integration in Empire too). The new echolink interface board will also help as it has built in adjustments and configurability to deal with such things as needed. I expect the new boards to be ready to install early in the week and installation to take place later this week (pending Daves schedule, etc).

The updating of the repeater and linking gear at the W8TVC site to Anderson PowerPoles will be done gradually over the next three months. There is much work to be done with the W8TVC repeater (Echolink pc updates, RC210 programming, antenna replacement, etc) and the power connectors will be changed as time permits.

Film at eleven...

73
John KF8KK

Intermittant feedback fix incorporated

2007-06-23T22:28:00.000-04:00

Greetings!

This morning (FD!) a small board with timing and switching logic was incorporated in the PORT-2 I/O for the W8TVC/r RC210.

Apparently, the RC210 would on occasion open up the audio path from the received PORT-2 audio during times when it was also transmitting on PORT-2 with the audio from PORT-1. This isn't supposed to happen, but it does. Usually this manifestation takes a few minutes of PORT-1 'key down' to start and commences with a popping sound and then opens up into a really swell echoey feedback until the Port-1 signal dissappears. The feedback loop included the Empire systems.

The added board simply disconnects the incoming (from the W8TVC RC210 port2 perspective) COS and audio whenever there is PTT asserted on port2. An additional timer is incorporated so that these inputs are not returned to active for a full second after outbound PTT ceases, this should take care of the effects of audio delays and switching times.

73 John KF8KK

W8TVC/r Controller upgrade project commences

2007-06-18T22:25:00.000-04:00

Greetings!

Today the new Arcom RC210 controller was installed at the W8TVC 145.27 repeater.

This installation will be spread over a few days and it's certain that a handful of 'gotchas' will be discovered and eliminated over the next few weeks.

Temporarily the Echolink node has been put in VOX mode until a phantom repeater-COS to Echolink signal is identified and eliminated.

73
John KF8KK

wI0OK-HD 145.36 DStar operational

2007-05-30T22:14:00.000-04:00

Greetings!

Egads, it's been a long time since the last post.

It's been a quiet fall and winter-- not much to post as it was.

Now that 2007 is here there will be a flurry of activity, as there is much that's planned.

I am pleased to report that on the afternoon of Wednesday May 30, the wI0OK__C DStar digital voice repeater became operational on 145.36 at the Glen Arbor / Empire site.

Presently, the Icom repeater is feeding 25 watts through a six cavity duplexer and into a diplexer that combines it with the 52.92 repeater and feeds it to the six meter antenna at 330' up the tower. An ARR GasFet preamp is also in the system for added receive sensitivity.

In initial testing, the repeater seems to radiate reasonably well, even with the non-resonant antenna.

This DStar repeater will ultimately be linked (via a 'remote base' type setup on the analog system) to the 444.725 and 52.92 repeaters, but at present it is a standalone system.

Ultimately, the DStar will be capable of selectively linking with the analog, and will also be setup so that it's data channel is ported back to the Leelanau Hamgate with plans to implement a DPRS to APRS gateway and Igate (APRS node on 144.39 will likely be added to the mix too). The ultimate uses for the data channel have not been fully determined, as it would be nice to have some form of text chat integrated with the DPRS data.

More news as it comes.

73
John KF8KK

Packet & Cabling Updates

2006-07-13T10:37:00.000-04:00

Greetings!

On July 6th the WGFN/WJZZ diplexer cavities were changed and all went well with that project (which included some internal mtce to the WJZZ transmitter). The following day, 7/7, I noted that the packet repeater at the site was not responding. On investigation it appeared to be operating with considerable transmitter desense.

On 7/9 I replaced the packet repeater on site, but with a better duplexer (Cellwave PD524) and all is well. In a/b testing to my home packet node I could not tell any appreciable difference in RF between the packet rptr running into the SuperStationmaster or the Diamond X50, so the repeater was left on the X50, where it had been previously.

On 7/9 and again on 7/11 various jumper cables were swapped out with 1/4" superflex heliax cables as replacements. There are just a very few lengths of 'consumer grade' coax jumpers left in the system at this site. At this time the 449.725 and 52.42 sensitivity was checked and appeared normal, the 52.92 transmitter is on frequency. The 444.725 transmitter is close enough to NOT tweak at this time (as it moves seasonally and appears to have been tuned so that on both hot and cold days it's within tolerance). The receiver frequencies had NOT been checked, but since the reception sounded normal when checking for sensitivity, they should be within tolerance.

73 John KF8KK

Misc update June 18

2006-06-18T14:28:00.000-04:00

Greetings,

Today the temporary jumper of 1/4" superflex at the W8TVC repeater (duplexer Tee to Polyphaser) was replaced with a more permanent section of 1/2" heliax. This beefier cable should hold up to the stresses that the RF places on the coax at that location.

Last night (6/17 11p) I modified the 440.05 link receiver in Empire to put the PL decoders into 'and squelch' so that the occasional false PL detection bursts that had plagued the receiver the past few weeks would not trigger the repeaters unless the squelch of the link receiver was also opened at the time. So far (14 hrs) it seems as though this modification has done it's job nobly as there have not appeared to be any phantom kerchunks on the repeater since it was wired in place.

73
John KF8KK

W8TVC/r back online

2006-06-12T22:11:00.000-04:00

On Monday evening Dave, W8TVC and I took a detailed look at the failure of the system that occurred on Friday.

While we didn't find a truely conclusive 'smoking gun', we did find a very questionable short coax jumper of Belden 8214 that would provide received noise if it was flexed. This jumper was replaced and the system appeared to be functioning normally.

Of note is that there appears to be a 2:1 swr from the antenna which may have been the normal condition, but then again it may not be. There is no apparent desense, and the system is stable (now that the questionable jumper has been removed). The repeater appears to radiate adequately and as expected.

While feeding the signal generator a signal on 144.67 into the six meter ringo, near full quieting was achieved with a -50 attenuator setting.

The replaced jumper was a 4' piece and located between the duplexer T connection and the PolyPhaser. The PolyPhaser appeared to be functioning normally and did not show any swr when RF was fed through it to a dummy load.

The calibrated sock was checked and found to be properly mounted, though no fine adjustments were made to it.

73 KF8KK

145.27 down for repairs

2006-06-09T21:41:00.000-04:00

It's with regret that the W8TVC 145.27 repeater is off the air temporarily for repairs. I expect it to be back in operation by early this coming week (the next few days).

At approximately 7:15p this evening the 145.27 carrier came on and two audible beeps were transmitted on the carrier approximately every 20 seconds. At the same time the link to the Empire system was keyed up and rebroadcasting the same audio.

The manner of the transmitter keying appears to be outside of the normal repeater controller, as a strong station (and when I say strong-- I mean 'ht in the backyard of the rptr') can key the repeater and pass audio (mixed below the beeps) and cause the 145.27 courtesy beep to generate. Stations not quite that strong could not generate such a response, apparently.

At approximately 8:20p the repeater was observed to have the far right LED on the MTR2000 flashing green, with the far left LED a solid green. The transmitter was not very warm for being keyed down for an hour. The 145.27 system was powered down pending a return to the site with test gear and documentation.

This is the first failure of the 145.27 repeater in quite some time (I'm thinking it's been two years or more without a problem).

More news as it develops... 73 KF8KK

Packet Changes

2006-06-03T22:44:00.000-04:00

Greetings!

On Thursday 6/1 I received an email from a few hams near Midland that reported packet interference to their 147.000 repeater. A snapshot of some packet data identified it as coming from the system here somehow. Midlands repeater being 120 miles away made this report rather astounding to both them and me.

Thursday afternoon I took the spectrum analyzer to the site and did some checking. At first I noted a questionable blip on the meter near the 147.6 input to the Midland repeater. This blip was very weak, and only visible from an antenna pickup up the tower (there was nothing visible when the packet TX was put into the meter directly). Even though the blip was weak, I moved the packet node from 145.07 to 145.09 as a precautionary measure, in the event it was a temperature related item and to give me more time to assemble a better measurement technique and ponder the possible modes that the Midland hams could be receiving the interference. All of my other transmitters appeared clean on the Motorola spectrum analyzer.

Interestingly, when moving the packet node to 145.09, that 'weak noisy blip' (had what looked like FM broadcast modulation in it too) had moved up the band and was now squarely on the 147.64 input for the Benzie repeater-- just 12 miles away. I monitored the Benzie repeater through the evening and there was no packet interference to it. Please note that up until early May, this same node was on 145.09 for the previous year and there was no interference to Benzie, through both cold and hot temperatures.

On Friday I returned to the site with more gear (attenuators, etc) and and measured that 'noisy blip' to be approximately 75db below the 39w carrier level of my 145.07 transmitter. (measured by a 2m dipole antenna about 6' horizontal from the packet transmitters antenna). Surely this weak signal could not have made the 120 mile trip to Midland.

On mulling over the captured packet headers, I now conclude that the reception was NOT of the 145.07 transmitter, but of the 433.100 mhz transmitter. The captured packets do have some irregularities that are rather questionable, so the cause may be something other than technical in nature. The 433.1 transmitter is the 10w UHF packet repeater on site. 120 miles is quite a hike for 433mhz, but, if the Midland repeater happened to have a 433.1mhz link receiver on their tower (and it was carrier squelch and omnidirectional) there is a possiblity it could be heard if conditions were 'just so'. [It would be an interesting test to transmit on 433.1 in the Midland area and see if the 147.00 rptr responded].

As a precaution, I moved the 433.100 packet repeater up 25khz to 433.125 (listening on 438.125) in expectation that this would eliminate the problem if there was indeed a 433.1mhz receiver atop the Midland repeater tower, or if there was a mix of 433.1 occurring at a site external to the Empire site (perhaps in Cadillac or closer to Midland) that was then getting into 147.60.

Time will tell if this is successful in eliminating the interference, as I would expect it depends greatly on propagation effects. As I left the site, there was no combination of transmitters that I could amass that would cause any intermod products (greater than that -75dbm noted earlier) that fell within 100khz of 147.600. I continue to monitor 147.600 at my workshop (TS2000 and a dualband ant at 50') and have yet to hear any packet energy on that frequency. Certainly if it was to make the 120 mile trip from Empire to Midland, it would be audible at 2 miles from my transmitter.

In other intermod related news, The work on the WGFN antenna system performed this past January appears to have eliminated the extremely strong intermod that rendered the 52.42 receiver useless last summer whenever the temperature exceeded 72 degrees. After a week of near 90 degree weather without any intermod (and I looked for it), I am all smiles that it is now absent.

73 John KF8KK

Voting system adjustment

2006-05-30T17:05:00.000-04:00

Greetings!

After a few days with the new Kenwood link receiver in place it appears to be functioning very well, but the audio output does not have the same 'composite equalization' as the former Motorola Motrac receiver had. The audio feed to the voting systems has more high-frequency noise energy in it than the previous receiver, thus causing the voting systems to mistake full quieting signals from the W8TVC site as being noisy.

With the assistance of Tom N8STZ on 52.42, I was able to adjust (via the placement of a .01mfd cap in the audio) the output of the link receiver to properly feed the voting receivers. The voters appear to be functioning properly now.

Additionally, this being the fourth 'hot' day in a row without any 6mtr intermod at the Empire site, it appears as though the intermod problem of last summer is gone. This is very good news. Apparently a potential source of the problem was discovered last January during a tower climb for the broadcast stations on site. I owe Glen Walker and Del Reynolds a few cold beers in thanks.

73 John KF8KK

TVC-Empire Link Operational

2006-05-28T00:40:00.000-04:00

I'm very pleased to report that the problem with the 440.05 transmitter was conclusively found and has been repaired.

Apparently, the problem was with the Motorola Mitrek since it left the factory, but took all these years to manifest. A small ceramic bypass capacitor was mounted too close to the circuit board and the body of the capacitor would contact the exposed trace on the board beneath it (which happened to be the RF output of the exciter) and when the 'heat soak' of the unit reached that portion of the unit the expansion of the metal caused electrical contact to be made between the capacitor and the trace, thereby shorting out the exciter output and hence taking the transmitter down.

While the link was down, I proceeded to make the following improvements/updates:

1: A 146.2hz PL decoder was added to the 449.725 receiver at the W8TVC location (so mobile repeaters will have the voting system available to them).

2: The 440.05 link receiver in Empire was changed from the problematic Motorola Motrac 'L' to a Kenwood TK860. With luck, this should solve the problems the old receiver had with seasonal frequency drift and occasional interference on the IF frequency. The Kenwood is multichannel and includes scanning, which may prove useful for future linking configurations.

3: The PL decoders for the link receiver were changed from the former RCA700 series decoders to Motorola Maxar/Moxy decoders. This should solve some false-dropouts that have been noted on the 440 side.

4: The Kenwood receiver no longer requires the GasFet preamp in order to hear the link transmitter, so the Lunar GasFet preamp has been removed from the site and returned to workbench stock. It's a refreshing change to actually 'simplify' even a small portion of the system.

With luck, the linking setup will return to it's highly reliable nature.... or even better.

73 de KF8KK

TVC->Empire link Offline

2006-05-26T23:38:00.000-04:00

Sadly, the 440.05 link transmitter at the W8TVC location is still failing.

At 8pm today (Friday) the transmitter was removed and the crosslink between the repeaters was disabled so the unit could be repaired on the workbench.

film at eleven.

73 KF8KK

Link transmitter maintenance

2006-05-25T11:28:00.000-04:00

Greetings!

On Wednesday it was observed (for the second time) that the 440.05 link from W8TVC to Empire had failed intermittantly during a long conversation. On this day, the link transmitter was failing repeatedly and appeared to fail in a manner that would cause one to suspect it was heat related.

Normally, when the 440.05 link is transmitting, it is received at an S2-S5 level at the KF8KK TS2000 in the workshop. It can also be heard mobile on M72 in the area. It was not heard when failed, leading to the diagnosis that the problem was at the transmitter side.

On checking out the transmitter at 8:15p I found the unit transmitting a rather variable amount of power. The wattmeter reading fluctuated as if it was an SSB transmitter... everything from zero to 8 watts.

I did some tweaking and it stabilized and was set to 10.4w. An external blower fan was placed to add cooling to the unit (there had been no fan on the unit since original installation two years ago). It appears to be functional, but only time and long qso's will indicate whether this was an effective repair. What caused the detuning is unclear. It had been a couple of years since it was tweaked so there may be an ageing component to the 'tuning drift', though it equally could be some components in the process of failing.

Film at eleven after the late news....

73
John KF8KK

Packet repeater update

2006-05-24T17:27:00.000-04:00

Greetings!
Both Monday 5/22 and Tuesday 5/23 saw maintenance and improvements added to the packet systems. Apparently during the previous week the 433.1 node (ben12) would not properly accept NetRom connections. Hard reset would only have the node functioning properly for a few minutes at best. The 'stats' page showed cpu loops in the 200 range-- not the 500-700 range as it should be. Something was amiss. Thankfully, this appears to have been corrected (bad trace was found on board).

New 3v lithium batteries were added to the 145.07 and 433.1 nodes. The 433.1 repeater was modified to improve transmit and receive performance with pre/de-emphasized packet stations. Additional work was done to eliminate some 'apparent jitter' in the repeated data and to eliminate the oddball 'data feedback' that would occasionally appear and lock up the system.

The Mitrek timout timer was also installed as a fail safe should the data feedback ever rear it's ugly head again.

A GasFet preamp was added to the 438.1 receiver for improved performance.

In other observations, the 440.05 link transmitter at W8TVC's appears to overheat and cease transmitting at times. Work on that will commence soon.

The backup battery charger at the 444.725 repeater appears to be working well.

73
John KF8KK

Link Antenna Upgrade

2006-05-05T14:48:00.000-04:00

Greetings,

On Wednesday 5/3 the antenna for the 440.05 link at the W8TVC site was changed from a six element Cushcraft yagi to a M2 antennas 11 element yagi. It appears (so far- two days) that the fading problems on the link are history.

On Thursday 5/4 the Cushcraft yagi, formerly used for the link from W8TVC, was placed in service at the 'KKBBS' Jnos hamgateway to link it to the 433.1 packet repeater at the hilltop repeater site. After some tuning of the gamma match, the antenna appears to be performing well in this application.

73 John KF8KK

CTCSS addition

2006-05-01T21:13:00.000-04:00

Greetings!

Today a CTCSS decoder for 146.2hz was added to the primary 449.725 receiver at the Empire site. This is to allow those with premium grade dualband mobiles to utilize the 'mobile repeat' function with the 444.725 repeater (the repeater transmits the 146.2hz tone with incoming signals-- mobile repeaters should operate in 'pl decode 146.2hz' in order to operate through the repeater without having to wait for the system to drop carrier before the mobile can transmit).

Additionally, work was done to the wI0OK-7 145.07 packet node to improve receiver performance. It was found that the addition of a GasFet preamp provided extremely minimal improvement in reception. This was NOT enough improvement to make it worth leaving the preamp in position-- the SyntorX already has the Motorola 'hi sensitivity' option installed (which appears to be working fine). It was determined that the packet TNC was seeing too much high frequency audio noise on the incoming audio line and a R/C circuit was added to reduce the hiss presented to the demodulator. This appears to have improved the packet decoding.

73 John KF8KK

Packet Node Changes

2006-04-26T21:02:00.000-04:00

Greetings! It's been a fine winter and the repeater ran well all winter with the exception of a period of time when it was extremely cold and the VHF remote base did not properly link 'to' the 147.04 repeater (rx of the Benzie repeater was OK). It is working now that I am back to look into it and no 'smoking gun' was found. The suspect components were not the problem.

On the packet scene, the primary packet node has been moved to 145.07 (from 145.09) and has a new call/alias of wI0OK-7 / BEN11 . Additionally, the secondary vhf packet node has been assigned the call/alias of wI0OK-8 / BENQMN and remains on 145.76.

The UHF packet node has been transformed into a bit-regenerative duplex packet repeater (1200 baud) and transmits on 433.100 with receive on 438.100MHz. This repeater is attached to the wI0OK-2 / BEN12 TheNet X1j node.

All the packet nodes at the site are TheNet X1j4 and have tcp/ip routing enabled and configured. The node on 145.07 is 44.102.152.23, The node on 145.76 is 44.102.152.24, and the node on 433.1 is 44.102.152.25. These communicate with my Jnos hamgate at 44.102.152.1 .

The 433.1 packet repeater has no preamp yet (it will need one) and operates using a Motorola Mitrek with 20w out of the six cavity 'mobile' duplexer. The packet equipment is connected to the Diamond X50a antenna at 100' on the tower.

73,
John KF8KK

Packet updates November 28

2005-11-29T01:21:00.000-05:00

Greetings!

Over the past week or so there has been some updates and changes to the packet radio node at the Empire repeater site.

The system as of today consists of an MFJ1270B running X1J-4 TheNet code (BENZ03) and feeding a SyntorX on 145.09 and into the dualband X50 at 100'.

There is also an MFJ1270C running X1J-4 TheNet code (BENZ04) and feeding the remote base SyntorX on 145.76, which is feeding the former 6mtr repeater antenna at 100'. Also on this 100' level six meter antenna is receiver #3 on 52.42 and #4 on 53.42 w/146.2hz pl.

The node stack for packet contains cabling that allows for a third node, which may be installed this fall if the weather continues to permit. The third node would be on 431.90 mhz and used primarily to communicate with a Jnos BBS in the KF8KK workshop.

Today I also was able to run the battery charger on the backup battery for a few hours. There was a power outage for most of the day earlier in the week and the battery was in need of recharging.

Otherwise, all appears well. KG8CU happened to come on the air at an opportune time and the voting receivers all appeared functional, his 5w signal on 449.725 still lit up all three receivers, and the signal to the #1 receiver was DFQ. He also lit up all three 52.42 receivers when on that band, though it wanted to vote for the W8TVC site.

The weather radio was also reset at this time.

73 de KF8KK

6m Rcvrs added - Packet TNC removed

2005-11-04T00:20:00.000-05:00

Greetings!

Due to some apparent intermod problems now affecting the tower site during the cooler weather, I decided it was time to move forward, at least in an interim manner, and add additional receivers at the main site. Looking at the VHF-LO RF coming down the antenna line from the former rptr antenna it is obvious that something new in the area is causing wideband noise--- as this appears different from the cellphone based intermod experienced during the summer. This intermod being more wideband in nature.

A 52.42 (RCA 700--- from the backup rptr) receiver and a 53.42 (146.2hz PL) GE DeltaS receiver was added to the system and connected to the old 6m repeater antenna (through a Comet Triplexer) at the 100' level. These receivers are now RX3 and RX4 on the LDG 6m voting comparator.

The 53.42 receiver seemed to tolerate operating without any RF filtering, though the RCA receiver needed the addition of one bandpass cavity to reduce the desense to nearly zero (though it's not quite there). The triplexer was installed to allow for future use of the antenna
by the 2m packet station. I will get one section of 52.92 notch stub in line with these antennas, as it appears that modulation on 52.92 does somehow get into the 53.42 receiver to some extent.

While at the site tonight, I also noticed that the MFJ1270C packet TNC had yet again crashed (three red LED's lit on the front panel). This is now the second time the unit crashed in the same manner in two days. It's obviously time to put the unit on the workbench-- and that's where it is.

Have a ducky day! 73 KF8KK

Power Supply-Voter updates

2005-10-25T20:37:00.000-04:00

Greetings!

Today saw the long awaited upgrading of the repeater power supplies and the new voter for the six meter receivers.

The two Astron RS50 power supplies which have been doing a yeomans job for years were finally replaced by two Astron RS70M supplies. Finally we have meters to indicate the loading on the supplies-- much easier to judge loading than the 'finger-on-heatsink' test.

With these new supplies, the 2mtr remote base and the packet station are now on battery backup. The only portion of the site that is not on battery backup is the 6mtr gear and the second 449.725 receiver at the site.

With just the 'exciters' running, the current draw is negligible and at most an amp on either supply. The 6mtr power amp appears to draw about 10amp (a bit low I think-- will have to look at that later), the 440 power amp appears to draw about 23 amps (more like it). The SyntorX on 2meters draws about 9 amps when it's transmitting.

The installation involved moving many items around in the rack, thankfully everything fit. As I left the site this evening the backup battery was accepting a charge from my portable charger.

I also installed the new LDG RVS-8 voting receiver controller. The first four ports are wired to the KK standard 9pin connectors for use with my 6mtr receivers. The present two receivers were setup with the new voter and appear to be functioning properly. I will add an additional receiver (or two) to the voter in the coming weeks.

While dealing with alignment issues on the new voter (which went easily and well it seems) I also touched up the setup on the 440 side with it's Doug Hall voter.

Since the installation was going well, I decided it was a good time to add the extra circuits to the special 'Benzie PL one-shot' circuit so that it only functioned when the remote base was dialed up on the 147.04 repeater. After a bit of soldering and a few parts, the added circuitry was in place and now the annoying 'squelch burst' when non-Benzie repeaters (or simplex) was dialed up on the remote base is gone. The Benzie circuit is only functional when the Benzie repeater is selected-- the way things aught to be.

More improvements to follow shortly.

73 KF8KK

Benzie Link on PL decode

2005-10-12T02:20:00.000-04:00

Greetings!

Today I've installed a small 'one shot' in the COS line of the 2mtr remote base transceiver. The purpose of this is to allow the use of 'PL decode' when linked to the 147.04 repeater for the Wednesday net. By using PL decode, stations connected into the system via Echolink will no longer have to wait for all the repeaters to drop carrier before they can transmit. Sadly, when we first setup the 147.04 repeater to encode (100hz) PL during incoming signals only, it turned out that the oddball 'beat' (a heterodyne/IF mix from something at the Empire site) that appears on the 147.04 frequency interferes with reliable PL decode-- causing dropouts.

The small 'one shot' delays the closure of the carrier (or PL) sense line and masks any PL decode dropouts.

At present, this delayed COS closure is manifest on ALL frequencies used in the 2mtr remote base (it will appear as a burst of open-squelch noise when distant repeaters unkey). I plan to install the circuitry needed to restrict the delay to just the 147.04 frequency within the next few weeks. Please pardon the squelch bursts in the interim.... it makes linking in Echolink connections considerably better.

73 John KF8KK

PS... the new power supplies and new LDG voter (to replace the current 6m voter) have arrived and will be placed in service before the end of the month.

Packet node NOT diplexed

2005-10-12T02:14:00.000-04:00

Greetings!

While the test of the packet node diplexed with the six meter repeater antenna was a huge success for the packe node (reliable connections to TAWAS and Midland) it turned out that in the field the small loss in transmitted signal on 52.92 produced a VERY noticeable loss in downtown Traverse City and other fringe areas.

The packet station was returned to it's former configuration, mutually exclusive with the 2mtr remote base transceiver. During the winter I will work on designing and building an appropriate diplexer to use to diplex the packet node with the six meter antenna.

Because the small (3w) power loss on 52.92 made such a dramatic change to the coverage 'downtown', I will bump up the plans to raise the repeater output power to 250w to a higher position on the 'list'. While I have the GE 'Power Mate' amplifier, I need some parts to complete it's operation-- and to rebuild the 6m duplexer to withstand the higher wattage.

Progress on this project will likely become noticeable in the spring/summer of 2006.

73 KF8KK

Packet Node diplex with 52mhz rpt antenna

2005-10-09T23:58:00.000-04:00

Greetings,

Tonight I have put in place an experiment to determine how desireable it would be to feed the 52mhz antenna at the 330' level (the main 6mtr rptr antenna) with a diplexed feed that included the 145.09 packet node along with the 52mhz repeater.

Initial experiments show that the Comet Triplexer exhibits acceptable insertion loss (36.9w reduced to 34.0w on 52.92) and that the 145.09 packet node (using the SyntorX remote base) has a dramatically improved connectivity to known distant packet stations. The observed SWR shown at 145.09 (using the 52mhz DB products folded dipole) is roughly 3:1. While the SWR is not very good, the apparent transmission/reception range is noticeably better and that makes me stand up and wave at the standing waves.

If the experiment proves succesful, a seperate packet transceiver will be placed on site to use this higher antenna and the 2m SyntorX remote base will be returned to the dualband antenna at 100' where it has been operating from. During the test, however, the 2m remote base is also using the antenna at 330'.

Film at eleven...
73 KF8KK

Aux 449.725 rx preamp

2005-10-03T23:52:00.000-04:00

Greetings!

Today I installed another ARR GasFET preamp in the 440 repeater. This preamp is feeding the second 'main site' 449.725 receiver with amplified RF off the former repeater antenna (the Super Stationmaster at 100'). This should improve reception in areas which have poorer coverage due to the tower shadow (downtown Glen Arbor, for example).

Simultaneously with the installation of the preamp is the installation of a single Motorola bandpass cavity in this second receivers antenna line.

73, KF8KK

Traverse Link RX checked

2005-08-20T23:33:00.000-04:00

Greetings,

After hearing what sounded like noise on the 440.05 link from the W8TVC location I found no real 'smoking gun'. All connections seemed to be stable and the measured sensitivity appeared to be normal. However, since the new 440 duplexer was installed there seemed to be intermittant periods of 'not quite solid DFQ' signal from the link transmitter. I swapped the antennas for the link receiver, putting it on the former 440 repeater antenna (it had been diplexed on the dualband X50 remote base antenna). More research to follow in time.

I also did some fine tweaking on the new UHF duplexer--- all was good.

73 John
KF8KK

New 440 duplexer

2005-08-13T23:28:00.000-04:00

Greetings!

Tonight I installed the 'new to me' (er, used --- via ebay) Cellwave PD524 six cavity UHF duplexer at the repeater. I was successful in removing the four cavity DB products duplexer that was on loan from Evan N8JKV. The system now has three cavities in the transmit side and four cavities (one additional Motorola bandpass cavity added) on the receive side.

While there was no improvement in receive sensitivity (which already is quite good), the power fed to the feedline went from 35w up to 57w, quite an improvement.

This frees up the former PD524 duplexer for other uses.

73 John
KF8KK

6mtr RX noise problem

2005-08-05T22:20:00.000-04:00

Greetings,

There's a severe noise problem affecting the 52.42 receiver at the Empire/GlenArbor repeater site. The noise is intermittent, but when it's there it's strong enough to render a 100w signal within visual view of the repeater antenna rather noisy, sometimes unreadable.

On Sunday 7/31 I spent a few hours trying to locate the source of the noise and had no success. Both the Mitrek transmitter and receiver were swapped out for the RCA backup units with no change. The antenna system was switched over to the (still in place) older system with no change. Each section of the duplexer was individually taken out of the system and there was no change... the TX/RX antennas were even split and no difference was noted. The amount of desense did not depend on the amount of power the repeater transmitted-- as it was the same at 5w as it was at 50w. All RF jumpers were swapped out to no avail. I ran out of time and returned the equipment to the way it had been previously-- except for the removal of the ARR 6m GasFET preamp from the 52.42 receiver.

During the past week the noise was prevalent quite often. The weather was unseasonably hot and muggy. When the noise is present, the repeater is useable if the station accessing it is within receive range of the W8TVC site receiver-- as the voting system does it's job well to allow that receiver to 'pick up the slack'.

Today the weather was more seasonable and with temps in the 70's (as opposed to the 90's) the noise is not present. Tonight I ventured up to the site to look into the problem and was able to document what the receiver saw from the antenna when there was no noise present. The system appeared to be functioning properly.

73 KF8KK

220 remote base repaired

2005-07-25T23:44:00.000-04:00

Greetings!

Tonight I finally FIXED the Icom IC37a 220 transceiver so that we shouldn't have any more problems with the 220mhz audio received not making it to the repeaters. The volume pot on the unit (which controlled the audio going into the repeater) had numerous 'dirty spots' and it would always seem to find a way to NOT pass any audio after a while.

I have replaced the worn out volume potentiometer with an internally mounted, brand new, hermetically sealed, 10 turn pot-- which should provide reliable service into the next ice age.

While at the site I charged the backup battery, reset the repeater clock to the correct time (it had drifted off by 5 minutes since last December), set the packet TNC clock, and replaced the RF cable from the 440 duplexer to the GasFET preamp with a cable made with superflex heliax. I also attempted to remove the additional 440 cavities (on loan from N8JKV), but it appears that the main duplexer is tired and in need of replacement or refurbishing. The system works as it is presently, but there is an extra 1.5db of loss in the system (both RX and TX) due to these extra cavities. I'll get a new duplexer on site within the next few months, and we'll squeak a few more miles out of it at that time.

73 KF8KK

Link RX frequency reset

2005-07-16T23:39:00.000-04:00

Greetings!

Sadly, due to caring for my dad, N8NCO during his final days (and the funeral issues), it took a few weeks to tend to the apparent frequency drift that the UHF receiver used in the link from the W8TVC site to the Empire repeater had developed. As the weather approached 90 degrees the receiver would drift further down the band, as the temperature moderated, the receiver would drift back toward normal reception.

Tonight I managed to spend an hour at the repeater and found that the receiver was tuned for 440.043--- seven khz low-- and just outside the range of 'useable'. I reset the receiver to the proper frequency and the system appears to be functioning properly now.

I also reseated the connections to the 6mtr duplexer and in my checks did NOT notice any of the odd noises that were intermittently present on the 6m received signal (no noise present both before and after the connector reseating). There is, however, a somewhat questionable connection in the factory 1/4" superflex connector at the polyphaser, which I will tend to soon.

More maintenance work to commence later this week as my schedule gradually returns to 'normal'.

73
KF8KK

New Antennas Connected

2005-06-18T21:55:00.000-04:00

Greetings!

I'm pleased to report that at about 3pm today the new and higher antennas for both the 444.725mhz and 52.92mhz repeaters were connected to the system and appear to be functioning properly.

The SWR on the 440 antenna is indicating a close to optimum match with little, if any, reflected power. The six meter antenna shows a 1.8:1 match with the repeater transmitting into it. Both repeaters appear to be putting roughly 50-60w into the transmission line (though the metering is not a benchmark for accuracy).

There is no perceptible desense. No interference from the nearby FM broadcast transmitters, or other odd noises have been noted. All appears good.

The grounding and lightning protection devices have been installed. Due to the new cable routing, the six meter output power sampler has been removed from the circuit pending longer
leads for the sample voltages.

73 KF8KK

Repeater Antenna Raising

2005-06-17T21:48:00.000-04:00

Greetings,

I'm overjoyed to report that today the new antennas for the 444.725 and 52.92 repeaters were raised to the 330'-340' point on the tower.

Thanks to the hard work and expertise of Glen Walker, Del WB8DEL, Keith WA8ZWJ, Mike N7LMJ and myself, todays work went smoothly and appears to be functioning as it should.

The antennas are oriented properly and affixed at the southeast leg of the tower. The 440 antenna is arranged to provide 9db of gain towards the east and downtown Traverse City. This is an 'offset-omni' arrangement with a very wide lobe of gain.

The six meter antenna is oriented towards the south and Evart.

There is a tower shadow that effects the areas near Glen Haven. It appears to manifest between the main intersection in downtown Glen Arbor at it's eastern edge, and the Glen Haven maritime museum at the western edge. Adding to the tower shadow is a rather large and ominous terrain feature that would be hard to pass a signal over regardless of tower shadow.

As of this date the repeaters have not been connected to the new antennas.

More to come, 73 KF8KK

Summer Alignment Notes

2005-06-07T14:57:00.000-04:00

Greetings,

Today was the day for the summer frequency alignment and audio tweaking at the main repeater site. Sadly, it was spurred on by the 'dirty pot' in the 222mhz receiver manifesting itself again. The volume control on the IC37A transceiver was exercised and hopefully the audio loss through it has been exorcised.

Additionally, the audio levels from 449.725 and 52.42 receivers was checked and set. Sadly the existing logic problem with the 6mtr voter board made adjusting the 6m side a bit tedious. I expect to change out the 6m voter with another board with my improvements incorporated at some time later this month.

The 444.725 transmitter was found to be 1.7khz low in freq, and the 52.92 transmitter was almost 1khz low. I brought both of these to about .25khz low. The temperature at the time was in the low to mid 80's outside--- typical summer weather. The VHF remote base was right on frequency when checked on 144.92. the 52.42 receiver had been adjusted about a week ago and was not checked again, neither was the two 449.725 receivers-- which will be needed to be checked on the next visit (oops-- I knew I forgot something).

Sadly, today it was noted that the 52.42 receiver at W8TVC was picking up a fair amount of what I would call 'AM Noise'. This had manifested about a month ago and never noticed since then, but it was back today. It was NOT on the UHF link between the TVC site and Empire, nor was it on the 449rx there, but it was on the six meter receiver only.

That's the latest... 73 KF8KK

Packet TNC reset

2005-06-05T12:31:00.000-04:00

Sadly, late in the evening on Saturday the wI0OK digipeater got stupid (mid connection to the wI0OK-1 mailbox) and returned to 'factory fresh' parameters.

On arrival at the repeater site the TNC was looking fine and appeared functional but the callsign had reverted to 'nocall' and all the localized parameters were reset to factory defaults.

Oh well--- let's hope this doesn't become habit forming.

73 KF8KK

Six Meter Receiver Tuning

2005-06-05T12:25:00.000-04:00

Greetings!

Today turned out to be the day to take the 52.42 receiver at the W8TVC site and move it up to the proper frequency from about 2khz low. Thankfully, swapping out a 10pf capacitor for a 5pf was all that was needed to bring the Mitrek channel element within tuning range of the desired frequency.

While at the site I also did some snooping into the intermittant desense problem that seems to be affecting the 145.27 repeater. While there was nothing that stood out as definately bad, it did seem that one of the cables (between the Polyphaser and duplexer Tee) might be suspect. I will have to return with a 4' length of superflex heliax (N male - PL259) and give that a try.

73 KF8KK

TVC voter alignment

2005-05-29T12:05:00.000-04:00

Greetings!

Today a new 6' equipment rack was installed in the W8TVC hat room to replace the former 4' rack that was overwhelmed with gear. The new rack has adequate space for the equipment in use, and some additional area for possible future expansion (it also looks nicer).

Once the gear was moved to the new rack (all of the voting receivers for 444.725/52.92, link tx/rx, and backup 145.27 rptr) the alignment and adjustments were checked. It was suspected that some of the audio levels had drifted downward.

Apparently the 52.42 receiver output was about 3db lower than it should have been. The audio levels were set to provide a -3db output from 144.67, 449.725 and a -4db output from 52.42.

The 440.05 transmitter was significantly on frequency and at 10w output power. The 52.42 receiver appears to be about 2khz low in frequency. Retuning of this receiver (involving changing caps in the channel element) will be done at a later date.

Alignment checking of the Empire end of the voting system will be done soon.

73
John KF8KK

6m RX freq adjustment and more

2005-05-16T01:15:00.000-04:00

Greetings!

Today (er, Saturday) I spent some time with the Empire 52.42 receiver and managed to bring the crystal 'right on' the desired frequency. When I arrived on site I found that it had drifted even further down the band than when it was last measured. Today it was receiving at 52.417 and last December it was at about 52.418. Sadly, the channel element (with xtal installed by Bomar) never really was able to make it to 52.42 (the 'ordered' frequency) since it was received. There is a similar (though not as far off) problem with the 52.42 receiver at the W8TVC location-- that will be tended to in the next few weeks.

While spending time with the repeater, I also changed the remote base inactivity timer setting so that it would have more of a tendency to unlink the remote base if there was no activity. The timer had been set to 30 minutes, which would never time out when certain repeater frequencies were dialed up (those with ID's that beaconed). The setting has been reduced to 7 minutes, which SHOULD allow the system to time out and unhook the link if no QSO develops when the link is turned on. This should alleviate some of the problems should the remote base be enabled and then the controlling station find themselves out of range unexpectedly. For those who are wishing to monitor a remote system for a scheduled QSO my best advice would be to kerchunk now and then to keep the link up.

Additionally, I attempted to set the 'DTMF second tone mute' for both 6m and 440. I thought I had done this a few weeks ago, but it seemed that it was just active on the 440 side. After entering the codes tonight, it seems as if it's no longer active on either port. Yet another gremlin shows it's ugly head in the controller. If things operated as they should, when you hit a DTMF sequence the first tone should pass through the system and all the rest be muted. I also shortened the 'inter-digit-dtmf-mute-time'... so that the muting period is shorter. These muting parameters are being changed in an effort to possibly eliminate the randomly intermittant 'dead carrier keyup' when stations come in on 52.42 and their audio does not pass through the system (but their COS/PTT does). The next step in this line is to remove DTMF muting entirely and see if that eliminates the manifestation of the problem.

Of interesting note is that numerous times today, while entering DTMF commands, the system blurted out erroneous command responses--- and would, at times, put the repeater into unusual operating modes. For those entering DTMF commands, please let me know if the repeater comes back with a response that doesn't make sense. The machine may need to be reset at that time also.

Otherwise, life is grand!.... er, ducky.

73 KF8KK

Repeater Firmware Updated

2005-04-29T01:30:00.000-04:00

Greetings!

In the (seemingly) never ending pursuit of a bug free repeater, I installed the RC210 version 4.30 firmware today. Thankfully, this version loaded and it should take care of the odd audio irregularities we've been having.

4.30 appears to have stable audio levels. I also hope it no longer has the problem where a station on 52.42 will occasionally find that his whole transmission was passed out of the repeater without any audio (just the ptt/cos). Time will tell. At the moment, everything I tested appears to function and I'm crossing my fingers.

Sadly, due to a hardware bug that's somewhere inside the board or Mega128 microprocessor chip, this will be the last firmware update for the forseeable future. The updates produced by Arcom past the 4.30 version appear to cause the 52.92 transmitter to come on and continuously broadcast the weather channel. Oh well.... so it goes.

The code to set the DTMF muting to mute starting at the SECOND (and subsequent) tones was turned on. I verified that it did mute on the second tone while I was standing in front of the rack at the site, but while testing again along the way home it appears as if it's muting (as it had in the past) on the first DTMF tone. Why this is happening will be investigated on the next trip to the site. The theory is that perhaps the 'no-audio-transmission' failure may be related to DTMF muting. While version 4.30 may have a fix for the 'no-audio-transmission' problem, it may also not have such a fix. The theories bantered about when the 4.30 version was originally created wat that the no-audio problem must have been related to DTMF muting in some way, and muting on the second code entered would likely eliminate a false triggering of the mute algorithm (and hence, eliminate the no-audio-transmission problem).

73 KF8KK

More Repeater Issues

2005-04-26T23:50:00.000-04:00

Greetings yet again!

After loading the 4.28 firmware into the RC210 it wasn't too long before the bug in that version related to the 'inactivity timer' surfaced-- causing the repeater to periodically report that the remote base was inactive and turn it off, even if the remote base was already off.

Additionally, I was able to witness firsthand, the bug that causes the 6mtr receiver to properly process the COS/PTT yet not pass any audio to the system (it happened to N7LMJ this evening). This is a problem that we hadn't noticed since the 4.29G firmware was loaded last December.

Adding to the list was what appeared to be an RF signal problem on the 440.05 link from the W8TVC repeater. I happened to be measuring some RF cables for replacement (with nice 1/4" superflex heliax) and perhaps I had dislodged a marginal cable feeding the 440mhz receiver. On wiggling the cable, the loss of signal would appear and dissappear (though I'm not certain that this was the root of the problem-- as during the test the noise would change in a manner similar to that experienced if there was another signal beating with the desired signal-- with all the noise in the repeater shack, it was hard to tell for certain).

I made up the needed piece of superflex cable (the permanent replacement that I was planning to build and install next week with a few others) and put that in circuit and now I can flex the cables all I want and the signal stays stable and strong.

I also attempted to load the newer firmware for the RC210, the 4.36 and 4.370 versions-- but both exhibited the same problems as the 4.375 did-- which is unacceptable. I was unable to download the 4.30 version from the Arcom site, and so I loaded the 4.29 (no letter) version in hopes that it was pre-audio-problems. After considerable testing, this first version of 4.29 (no letter) does NOT have the audio level problems. Sadly, I remember that at the time the 4.29 firmware came out there were numerous attempts at fixing a problem where intermittantly the audio would not properly switch--- so, I'm not certain what problems we might experience with this firmware. Time will tell. This 4.29 firmware should eliminate the problem with the inactivity timer alerting when it's not supposed to.

After a fair amount of testing, the system was returned to service and all seems to be functional.

73 KF8KK

Audio problem fixed

2005-04-26T16:42:00.000-04:00

Greetings!

Today I concluded without a doubt that the audio level irregularities the repeaters have been experiencing since December were indeed brought on by the version 4.29 firmware in the RC210 controller.

Sadly, upgrading to the newer 4.375 software opened up a different problem that is even less tolerable. This latest software causes the 6mtr transmitter to remain keyed-- and playing the weather radio-- full time. Even attempting to disable the 6m transmitter just caused the controller to readback that it was going to do that, but it stayed transmitting. Harumph.

I downgraded the firmware to version 4.28, which appears to function properly. Surely there are some caveats with the 4.28 firmware (as 4.29 was a bug fix). The repeater had been running with 4.28 for a few months last fall without noticeable ill effects. With the 4.28 firmware, all the audio levels are steady. Sadly, there are a few newly added features that the latest 4.375 firmware would have added. Oh well.

The audio levels were set so that what comes into the repeater leaves the repeater just the same. The Weather Radio works just as it should also (this was broken in the 4.29 firmware-- along with the audio level problems).

Film at eleven...
73
John KF8KK

2m remote base & packet digi operational

2005-04-26T02:44:00.000-04:00

Greetings!

Monday 4/25 saw the return of the SyntorX two meter remote base transceiver to operational mode at the repeater site. With this return the ability to properly encode the PL tone when the 146.78 Manistee repeater is selected, and the ability to require a 100hz PL tone on the 147.04 Benize repeater for linking have been added.

The 100hz tone for Benzie was chosen in order to avoid conflicts with other tones in the system should some of it leak past the PL filters. This completes this end of the upgrade that will ultimately allow for better Echolink function when the 147.04 repeater is linked in for the weekly net (Wednesdays at 8:30p). The PL tone encoding still needs to be added to the 147.04 repeater for this new mode to be operational. In the interim, a means has been provided to link to 147.04 in the 'former' carrier squelch manner.

The 2mtr SyntorX is now setup to rest on 145.09 when not in use as a remote base for the repeaters. When on 145.09, the audio/cos/ptt is switched away from the RC210 repeater controller and over to an MFJ 1270C packet TNC. This will give the SyntorX something to do during those times when the repeaters are not linked to other systems (which is the vast majority of the time). The packet station uses the callsign 'wI0OK', with a mailbox at 'wI0OK-1' and a digipeater alias of 'LEEL' (for LEELanau county).

More repeater work to be completed shortly.
73 KF8KK

2m Remote Base Offline

2005-04-21T17:09:00.000-04:00

Greetings!

Today I pulled the 2mtr SyntorX remote base transceiver from the repeater in order to make a few changes to it's configuration.

I expect to have the unit back in service this coming weekend.

More information on the changes will be forthcoming once they happen. I also plan to tend to the audio level problem on the repeater (along with other updates) this weekend as part of this project.

73
John KF8KK

444.90 Lake Ann Rptr repaired

2005-02-06T11:58:00.000-05:00

Greetings,

Today the wI0OK/r 444.90 repeater hosted by N7LMJ in Lake Ann was returned to service after a brief time offline (removed for repair late on 2/4). I am happy to report that the repeater is back up to 100% performance as far as can be measured.

The repeater had developed 'Mitrek Disease' sometime over the previous few months. Mitrek Disease is a loss of receiver sensitivity (dramatic in some cases) due to poor solder connections between the helical resonators of the receiver and their shielding. Over time the connections fail and the receiver 'front end' tuning changes. In this case, it looked as if a couple of the resonator sections had poor solder joints from the factory. The receiver tuning would change with the transceivers temperature-- yet never fully become optimum. The 449.9 receiver was noted to be anywhere from 20 to 40db less receptive than it should have been. A few minutes with a propane torch and some solder (and flux) was all it took to heal the receiver.

After the repair was made and the system returned to service the sensitivity was measured and found to be amazingly good. 0.06 microvolt into the duplexer antenna port would key up the repeater. By the time you got to .1 microvolt reception was near DFQ (this was with the ARR GasFet preamp in line).

Yee Haaa!
73
KF8KK

GasFet preamp added TVC-449 rx

2005-01-16T14:20:00.000-05:00

Greetings!

Today a fresh new ARR GasFet preamp was added to the 449.725 receiver at the W8TVC site.

The measured system sensitivity of the 449mhz receiver improved by about 10db. That's a nice improvement. [measured by putting the signal gen into the 6m antenna. 449mhz squelch opened at -40db before and -50db after the preamp was inserted in the system]

73 KF8KK

Phantom link glitch expunged

2004-12-19T20:05:00.000-05:00

Greetings!

Today Dave, W8TVC and I installed a small circuit into the link for the 145.27 repeater to eliminate the phantom second squelch tail on stations entering the system from 144.67. This extra tail was caused by the aggregate summation of the PL decoder 'hang-in' along the link path and manifested itself as a quarter second of the 444.725 repeaters audio inserted on the 145.27 transmitter at the end of every 144.67mhz transmission. This also caused the 'ping-pong' bouncing occuring on many echolink connections. Hopefully it will clear up the 'bull horn' beep that somehow appears now and then on echolink connections. The cause for this occasional manifestation hasn't been fully determined, so this fix may have no effect on that situation.

We also updated the Echolink software to the most current version on the W8TVC node. Sadly, this version may not be stable on the computer we use as it has crashed the machine twice since it was installed. Work is underway to provide an adequate and reliable method for remote echolink users to control the remote bases in the system. Sadly, the DTMF pad in the newer Echolink software does not seem to be the best approach for making this functionality useful in this particular system (DTMF twist and kerchunker filters get in the way). My prospective workaround should be not only adequate, but easier to use.

The audio level irregularities continue, and will likely so until the spring. Thankfully the audio levels have been adjusted so that they are 'reasonably close' to optimum for most of the time. Occasionally the system will overmodulate a little for transmission, but this is tolerable considering all issues.

Film at eleven...

73
KF8KK

Audio Levels Update

2004-12-11T16:23:00.000-05:00

Greetings!

Thanks to the continued good access to the repeater site I spent some time today troubleshooting the audio level fluctuation problems in the repeater controller.

Sadly, the problem is not limited to the 'audio crosspoint' switching IC, but appears to be an intermittant trace or a poor solder connection on the circuit board.

After swapping in a new crosspoint chip the problem persisted. I removed the board and reflowed the solder on the connections near that crosspoint chip. I'm not certain, but there may be some improvement, or not-- as my testing setup was lacking. I did, however, boost some of the levels to the 444.725 and 52.92 transmitters in hopes that it would make the problem more tolerable while we 'lived with it' for now.

Further troubleshooting will be lengthy and involved and require a period of time for the controller to reside on the workbench. This will not be attempted until the spring.

While at the site I programmed an Echolink speedial for the AL7RV node in Florida.

73
KF8KK

Loose Belt possibly tightened

2004-11-29T01:19:00.000-05:00

Greetings,

On Saturday the first attempt was made to cure the 145.27 system (linked into the wI0OK system) of the intermittant 'loose water pump belt' sound. With careful consideration, the prime suspect was the Echolink equalizer box portion of the 145.27 controller. It was noted that the past month or two the 'canned speech' from the Echolink software was unusually 'tinny' and 'sharp' (having considerable high frequency audio energy). Perhaps the pre-emphasis circuit in the interface had a component failure and was on the edge of oscillation.

I reduced the amount of equalization tilt in the interface, which brought the Echolink status announcements into a more pleasant sounding state. While at the site, varioius audio adjustments were made (some of which later had to be undone on 11/28). Frequencies were checked and adjusted as needed, with the exception of the 52.42 receiver which (like the receiver in Empire) was found to be on 52.419.

It was noted that there's a 'ping-pong' that sets up when Echolink is connected to certain systems (the test server and WA5KUB sites had this) that appears to be related to the speed at which the COS signal from the Echolink software progresses through the linking system. When Echolink unkeys there is a slight delay before the PL decoder unkeys at the W8TVC 444.725 receiver used for the Empire-->TVC portion of the link. This slight delay is enough to trigger a transmission via Echolink to the remote node, which sometimes is mysteriously bounced back. The bounce-back from the remote site was not noted in connections to the K2TC node, which seemed to ignore the momentary echolink keyup. This problem is still under investigation.

Another Echolink problem was noted and solved. Interestingly, with the addition of the '#' command to the Empire system for use in disconnecting the W8TVC echolink node, users on 145.27 were unable to disconnect the echolink connections. A station on 145.27 would hit the '#' to disconnect, and their # would register in the Echolink computer, but their # would also propagate through the links to Empire where it would be regenerated on the 444.725 transmitter, and then decoded by the same Echolink computer and added to the other '#' that was entered. Effectively, hitting a single '#' on 145.27 would enter a '##' command on the Echolink computer. [Note that hitting '#' from 444.725 or 52.92 worked as expected, entering a '#' command on the Echolink computer.]. Because of this code conflict, the Empire repeater Echolink disconnect code was changed to a '*'. Users on 440/6m need to enter a '*' to disconnect Echolink connections from the W8TVC node. Users on 145.27 can use either a '#' or a '*' to disconnect the Echolink node.

While working on Echolink, there were two other code conflicts that were changed to eliminate potential problems. Sadly, users from 145.27 will find conflicts with entering the commands to put the Empire remote base on 146.52 or 146.76, as these would simultaneously initiate Echolink connections in addition to linking on two meters. Most all of the other commands to the Empire repeater (when entered on 145.27) would generate the begnign 'not found' response from the 145.27 Echolink computer.

FYI--- at the antenna terminal of the 145.27 duplexer the power level was measured at approximately 75 watts.
The 440.05 transmitter was measured at the transmitter output to be approximately 9 watts.

While at the Empire site it was noted that there is an irregularity in the audio system that causes random (one in every ten) audio level jumps of about 6db. These level fluctuations were not localized to any input and appeared on both outputs (unknown if simultaneously). There was nothing noted to affect the levels by physical shock or 'therapeudic touch'. Approximately 3-4db of gain was added to the 440 and 6m transmitters, as the more commonly found audio levels were below optimum by about 6db. The current adjustments 'split the difference' so that should the audio jump to the higher level, it will be 'hot' but not overtly so, and when the audio is on the more common lower level it will be lower than optimum but within reason. The repair for this will likely be time consuming and involve removing the controller to the workbench for a few days-- a project for the spring, not right now.

Additionally, the 6mtr voter appears to be having a problem voting. Perhaps a hanging chad is gumming up the works, perhaps it's detected voter fraud. Either way, it seems to not always want to vote as it should and can leave the audio of the poorer receiver switched into the system. I had not brought adequate documentation to deal with this unexpected problem with todays trip. This may or may not be resolved quickly.

Finally, the command to initiate an Echolink connection to the WA8ZWJ 442.85 repeater has been put in the system with the Echolink node of '9999' setup temporarily. This will allow for connections to the test server until ZWJ's repeater is equipped with Echolink.

More news as it's available.

73
KF8KK

Firmware 4.29G -- 220 audio

2004-11-25T01:31:00.000-05:00

Greetings!

Today a new version of the firmware [program code 4.29G] for the RC210 was installed. This version includes a fix for the audio muting problem on the remote base port when it decodes a DTMF tone.

Additionally, the audio and PL levels for the 220 transmitter were set to be as near 'optimum' as possible at the moment.

Sadly, it appears that the weather receiver audio isn't making it through the system when it should. The weather alert alarm function appears to be working, and there is audio coming out of the receiver itself. It could be either a relay contact in the receivers audio path (yes, there's a relay in there) or an error in the program code for the repeater controller (just as possible). I didn't have the proper tools to diagnose this at the time and it will have to wait for my next trip to the site-- whenever that may be. Since the alarm function is still functional, that's the important part (most modern mobile transceivers have weather radio reception capabilities), it's less important to actually be able to rebroadcast the weather on the repeater as it is to alert users that bad weather is on the way.

With any luck, this hopefully will be the last repeater maintenance at the Empire site for this year. We'll see...

73
John KF8KK

220 link repaired

2004-11-23T20:32:00.000-05:00

Today I found that the PL encoder on the Icom IC37A 220 transceiver had apparently ceased to encode tones. While I would have preferred to repair the internal encoder in the transceiver, it was a more timely and quick repair to insert a ComSpec TS32 encoder inside the unit. The unit is now working, but in operational testing after leaving the site the audio on the transmitter is a bit too 'hot'. I'll get back to the site and turn that down soon.

Sadly, during a qso, it appeared that the COS from 220 worked as it should but for that one transmission the audio crosspoint never opened up the audio-- dead carrier with PL on 444.725 and 52.92. Harumph.

In related news, on Sunday 11/21, Keith WA8ZWJ was given the 'repeater tour' and we also upgraded the RC210 controller to the latest firmware 4.29E.

73 KF8KK

Winter Maintenance Update

2004-11-12T01:14:00.000-05:00

Greetings!

Today was a fairly cold day and so I decided to take Johnny KG8CU's Motorola service monitor to the site and check and adjust the frequency settings to put the system in 'winter' mode. FYI-- both the 444.725 and 52.92 transmitters drift DOWN the band with heat. They both were adjusted a half kHz high at rest so that as the rptrs get used they should slowly drift through the correct frequency. No major surprises were found in the tests/adjustments (they were incredibly close to where they should be which was a small surprise). Sadly, the 52.42 receiver crystal needs to have the trim cap in the channel element changed as it's about 1khz low with the adjustments max'd out. CTCSS encode levels were also checked and found to be within tolerance.

I also uploaded the latest RC210 firmware 4.29A and did some minor housekeeping on the programming.

Included with the programming was commands to initiate Echolink connections to the WA5KUB and K2TC (Memphis and New York City) repeaters via the W8TVC Echolink node. These two commands (and the requisite disconnect command) was tested and worked great.

Within the few days before this update the backup battery was fully charged up.

This evening Mike N7LMJ was given the full 'repeater tour' and markings were placed on the cabling involved in switching the system to the backup controller to make it easier to switch controllers.

On Thursday, 11/11, an odd unstable audio oscillation was heard on signals coming in on the link from the W8TVC site. This oscillation appeared to be steady when it appeared, and change pitch on unkeying, but it was not present when I was at the site to look into it. When the oscillation was heard it was the first cold day of the season, though the evening when I was at the site doing mtce was yet colder. It's been a few days since the tone was heard and it has not reappeared.

Today the documentation was updated and backup CD's were created.

73
KF8KK

Updates and enhancements

2004-10-31T01:14:00.000-05:00

Greetings!

I'm happy to report that the newer receiver for the TVC link (voting receivers, 145.27 link) has been installed and appears to be functioning well. It's possible that with this change there may be tweaks needed to assure the voting systems are unbiased, but I am encouraged that the newer receiver will work so well we'll all forget that it's in the system. Time will tell as to whether it's all it's cut out to be. I expect that we've heard the last of the interference from the shorwave broadcaster on 12mHz.

With this update comes a few more linkable local repeaters. An updated 'cheat sheet' will be forthcoming denoting the additional frequencies available. Of note also is that the 2mtr synthesized remote base, when operated in VFO mode is set to encode a 114.8hz PL tone. This is an interim solution until the remote programming of the PL tone can be done, but that's likely a ways off.

Of interest also is the change to the remote base inactivity timer. This timer now will cause the repeater to key up and say 'link under active timeout... remote links off' when it unlinks the remote base after 30 minutes of inactivity. The timer now will fully set the remote base back to the known default mode too, instead of just unlinking it.

With this update is the loading of the newest 'beta' firmware for the RC210 controller, version 4.29. Hopefully this latest software will be reliable and trouble free. There's a phenomenal amount of complexity in the system, when it runs smoothly it's a wonderment.

73 KF8KK

Voting/TVC Link RX work

2004-10-30T11:42:00.000-04:00

Greetings!

I'm happy to report that the crystals have arrived from Bowmar and the new 'Motrac M series' receiver for the link from W8TVC has now been tuned to frequency. I now need to pull the existing 'H series' receiver down from the repeater and swap in this better one. With luck, this should only take a few hours.

The plan is to start this work about 5pm today, Saturday Oct30, with the removal of that receiver (which disables the 145.27 link and the remote voting receivers). If all goes as planned, I will return to the site later this evening (again, Sat 10/30, likely around 10pm) and install the new receiver. The new receiver should not be prone to interference from shortwave broadcasters (or so we hope).

If all goes well, I may update the RC210 controller to newer firmware that allows the unit to notify repeater users when the remote base times out due to inactivity. Presently, when there's no activity on the remote base for 30 minues (and it was enabled) it quietly/silently disables the remote base. It'd be nice to get an indication on the repeater when this occurs (helpful if a sked has a vague start time). I also plan to put the battery backup battery on charge. In the past month there was a period (about 10 hours) where the site lost power and the repeater was running off the battery. The machine operated fine in this mode, with the only notable oddity being that the PL encoding on the 444.725 output was continuous with PTT, which is a minor annoyance but something to ponder.

I'll post another update once the new receiver is re-installed.

73
KF8KK

Repeater On Vacation

2004-10-21T01:46:00.000-04:00

Greetings!

Since it seems most of the regular users (and all the control ops) for the wI0OK 444.725/52.92 repeater are taking a few days vacationing out of town it has been deemed appropriate to let the repeaters have a few days of rest too.

In other words... the repeater will be off the air for a few days.

I expect it to resume normal operations late in the evening on Tuesday 10/26.

Thanks for your understanding.

73
KF8KK

Anonymous Mode

2004-10-05T02:26:00.000-04:00

Harumph...

Today (er, Monday Oct 4) found the repeater apparently working normally, but it would not automatically identify. If the ID's were called up using the '888' ID command, it would ID both sides (6m vs 440) properly, which confirmed that the repeater knew who it was-- just that it wasn't wanting to broadcast this to the world without someone prodding it with tones.

Issuing the code to force the 2am housekeeping reset didn't make the ID's reappear. Harumph.

Late in the evening I issued the remote software reset (and then set the repeaters clock and date) and that caused the ID's to return to normal functionality.

The cause of the 'anonymous mode' is still unknown. Harumph.

73 KF8KK

Link RX & Battery Backup work

2004-10-03T01:01:00.000-04:00

Greetings!

Tonight I made one final 'last ditch' attempt to alleviate the 12MHz shortwave interference from the UHF link receiver. This involved increased shielding of the old Motrac receiver. While I did measure an improvement on the workbench, it's hard to determine if it's enough. Time will tell. Sadly, the next alternative involves ordering crystals which will slow up the resolution by a couple of weeks.

I also added a little kludge box to the system to 'brute force' solve the problem of the power sneaking into the 6m Mitrek from some 'back door' during operation off of the backup battery. My earlier fix, did not appear to solve the problem of the 'continuous beeping' (6m cos triggering repeatedly) when the repeater was operating off of the backup battery. It's not pretty-- but it will assuredly get the job done while I explore the circuit and figure out a better way. While I was at it, I also added a power-cutoff for the UHF link receiver so that that unit goes dead when the AC power does. I noticed that the receiver PL decoders didn't like the slightly lower voltage of the battery, and they were operating erratically on the backup power. My new relay box cuts off the 6m COS line and removes power to the link receiver when the AC mains goes out. The repeater was run for about 15 minutes on the backup battery power and it seemed to function well. The 220 link worked fine, but the weather radio oddly would not hold up the PTT on the repeaters (it does work properly when on A/C power).

There were a few other minor programming changes performed tonight also.

Hopefully good progress on both issues (link interference and backup power operation) has been made tonight. Time will tell...

73 KF8KK

Miscellaneous update September 26

2004-09-26T22:16:00.000-04:00

Todays repeater work included a little bit of everything all over the place.

The 444.725/52.92 repeater controller had gone stupid and forgot that it needed to send Icom CI-V format data to the 2mtr remote base. I reset this in the controller and all is well now. Hopefully 'going stupid' will not become a common occurrence.

I also changed the 'pending ID' timers so that the repeaters will ID in CW when it senses activity using the repeater. The six meter hang time was also extended a second and the 440 timeout timer was also lengthened a bit.

Today we saw a repeat of the interference problem on the link receiver from the W8TVC site. At times the interference was strong enough to capture the receiver and close the PL squelch on the signals coming in on the link. I believe this is caused by a strong shortwave broadcaster that operates on the IF of the old Motorola Motrac H series receiver. This problem had occurred in the units last use, in 1991, and it was hoped that some repairs to the receiver would have solved it. The next step in solving this issue is the use of a different receiver, which will be pursued. It'll take a month or more for a new receiver to be put in place, patience with it during the times when 'Radio Caracass' is broadcasting the 'Juan Reyes' show 'beamed to North America' is the best we can do for now, sadly.

Sadly, the '14692' remote base link to the N8JKV repeater in Lake Leelanau does NOT reach Evans repeater with it's operating on the temporary rptr antenna (Evans temporary antenna). I suspect this method of linking to the JKV repeater will continue to be inoperative even when the repeater returns to full coverage, as there is a very strong 146.910 repeater heard at the 440/6m repeater site. Good news, however, is that the 444.725 remote base transceiver for the N8JKV repeater was tested and adjusted today and should work splendidly for linking once the repeater returns to atop Evans hill.

As an adjunct to some unrelated work at the W8TVC 145.27 repeater today, it is now possible to command the W8TVC echolink node from 440/6m. The DTMF is being decoded at the W8TVC site with varying amounts of reliability. More work on this may be needed, but it's mostly where we want it to be. Additionally, adjustments were made to reduce the 'link dropout' heard on 440/6m when stations on 145.27 were either noisy or unusually loud.

Finally, the audio levels were set and adjusted at the 444.90 N7LMJ repeater and Echolink node today. All was found to be reasonably close to proper with the exception of the Echolink-to-repeater/link level, which was turned UP about 12db.

73 KF8KK

Assorted system news 9/25/04

2004-09-26T01:36:00.000-04:00

Greetings!

I'm happy to report that the link with the W8TVC/r 145.27 repeater is up and functional.

I'm referring to the 'system link' and NOT the remote base linking via the '14527' command from the 444.725 or 52.92 repeaters. This 'system link' is comprised of a connection (and extra receiver) residing at the W8TVC location. By linking the two repeaters in this manner the users of 145.27 can benefit from all the remote base functionality of the Empire-GlenArbor repeater. As with the 'remote base 145.27 link', users from 440/6m can also communicate via the W8TVC echolink node.

One caveat to note is that while the users of the 145.27 system can issue DTMF commands to the GlenArbor-Empire repeater, they will NOT hear the command acknowledgements or courtesy tones coming through on 145.27. Similarly, while the weather receiver can be dialed up from 145.27, it will only play on the 440/6m system (and get automatically reset after a certain time). The system is setup so that courtesy tones, ID's, meter readings, etc do NOT get linked between the two repeaters in order to provide cleaner communications for the system users. In this manner, additional systems can be linked in without having a buildup of unnecessaary beeps, tones, and confusing ID's. Remote echolink users will NOT have to wait for the the 145.27 or 444.725/52.92 repeaters to 'drop' in order to transmit (they will have to wait for any remote-base linked repeaters to 'drop' before transmitting should such links be enabled during an echolink connection).

At the present time, DTMF commands from the 145.27 system will be decoded by the 440/6m GlenArbor-Empire repeater. Sadly, the converse is not true. DTMF commands sent from the 440/6m side do NOT yet get decoded by the 145.27 repeater or its Echolink node. This will eventually be working, but it's not likely to happen very soon. When it does become functional, this mode of linking the repeaters can be turned ON or OFF from either side of the link (either 145.27 or 440/6m), but for now it's only controllable from the 145.27 side.

There is a distinctive courtesy tone that plays on the 145.27 repeater when this link is operating, regretfully there is no such indication of link status on 440/6m. Unlike using the '14527' remote base mode to link to the W8TVC repeater, when the 'system link' is in operation there are no audible courtesy tones or ID's from the W8TVC repeater heard on 440/6m, the audio heard is just the repeater users 'in the clear' (which is highly desireable if it is desire to link a third system via the remote base). To users on 440/6m, a user coming in via the 145.27 repeater is indistinguishable from a regular user on the 440/6m repeater who is using the 449.725 repeater input.

Additionally and unrelated.....

The firmware used for the 440/6m Arcom RC210 controller has been downgraded to version 4.27. This returns the remote base inactivity timer to full functionality. If the remote base port doesn't hear a signal for 30 minutes it will silently turn off the remote base link.

I also was able to recalibrate the RF output power metering and perform a handful of other minor tweaks and changes. The output power measured at the point where the duplexers connect to the feedline is approximately 45w on 440 and 48w on 6m. The PL encoding in the 2m remote base VFO mode is still non-functional.

On leaving the site tonight (9/25) the backup battery was put on the charger.

73 KF8KK

RC210 Controller back online

2004-09-14T22:38:00.000-04:00

I'm happy to report that the freshly modified RC210 controller chassis is back in service at the repeater site. The buffers to isolate the RC210 microprocessor from the outside world (the data lines to the 2m remote base synthesizer were previously direct to the Mega128 microprocessors pins) are now in place and this should keep any RF on the lines from getting into the unit and 'fooling with it's mind'.

Being that the original problem was intermittant in nature, it may take some time to determine if this work had any effect. I'm also curious as to whether the remote base port 'inactivity timer' has started to work now that this mod is in place. The inactivity timer (which disconnected a remote link after 30 minutes of inactivity) ceased to function at about the same time that the VFO mode was enabled and firmware 4.28 installed. I had previously blamed the failing inactivity timer on the 4.28 firmware, but it could have been an early victim to RF on the data lines. Time will tell.

73 KF8KK

Backup controller online -- updating underway

2004-09-14T19:49:00.000-04:00

Greetings!

At about 7pm today I switched the repeaters to the backup controller (both 6m and 440 repeaters are functional, but the other 'bells and whistles' are not) so I could put the modifications into the main controller to buffer the data sent to the SyntorX 2m remote base.

As I write this (7:50p) the modification to the RC210 chassis (adding a cd4049 as a buffer for the data and clock lines) has been completed and tested on the workbench (using an oscilloscope to observe the data) and is ready to return to the repeater site. In IOOK style, I cannot interrupt my dinner for such trivial things as repeater work, so the controller will not return to the site until about 9pm, after dinner.

With luck, this will solve the oddball 'controller losing its mind' problems. It certainly isolates the RC210 processor from the outside world (which is a good safety measure in and of itself). Only time will tell if this cures the intermittant oddities.

More later after the main controller is back online.

73 KF8KK

RC210 controller losing its mind

2004-09-14T01:55:00.000-04:00

Greetings....

Sadly, it seems that the RC210 repeater controller has been having problems with sanity of late.

The problems are intermittant and seem to occur at random times and with random changes of 'mode'. Sometimes it just drops the link between the 6mtr and 440 repeaters... other times it just makes a receiver inoperative, or a transmitter. I've seen where it split the repeaters and dropped the hang time to zero on one. In some cases it fixes itself in a few seconds, other times it requires a reboot.

This seems to have become noticeable after the controller was updated to the version 4.28 program, and the SyntorX VFO mode enabled.

While it would sound logical to blame the problem on the new 4.28 firmware, knowing how the data gets from the RC210 to the SyntorX VFO makes makes me suspect that RF is getting into the communications line between the SyntorX and the RC210. (this data line goes directly to the RC210's microprocessor without any buffering or RF bypassing-- not the nicest thing to do in such an environment).

I plan to pull the RC210 down from the site sometime in the next couple of days and install some buffering. It's not a big job, but not something to do 'on site'. The modification should only take a few hours and I may just let the repeaters rest 'off air' while I put in the modification.

When the work is to be done I'll post a note here.

73 KF8KK

Six Meter system improvements

2004-09-14T01:47:00.000-04:00

I'm happy to report that the 52.92 repeater now sports two full sized bandpass cavities in the antenna system. One bandpass cavity is in the transmitter line, and the other in the receiver. These will not only assist the duplexer in isolating the transmitter from the receiver, but they will also keep the entire system from sustaining interference from the two broadcast stations transmitting at the site.

Thanks for Dennis, KA8ABM for the two cavity filters!

Now that these filters are in line, I was able to install the ACC GasFET preamp into the receiver circuit and it gives a measured 2-4db improvement in reception from the 52.42 receiver at the repeater site.

I was also able to turn the power control to 'full' and the repeater is now putting out 90watts (up from 30) into the feedline to the antenna. Perhaps the added power will be a bit more noticeable than the receiver improvement.

What's nice is that there's not even a hint of desense with the preamp and the higher power.

73 KF8KK

2m RB VFO mode PL encoder inoperative

2004-09-10T23:41:00.000-04:00

Greetings,

It is with a heavy heart that I report that the setting of the PL/CTCSS encoder for the 2 meter remote base transceiver in VFO mode (commands beginning with '1442...') does not appear to be functioning at this time.

The command had worked a couple of weeks ago when the VFO mode was initially made functional, but for some reason it has ceased to work for reasons unknown. The SyntorX/XCat appears to be accepting frequency and transmitter offset commands just fine.

Sadly, at the moment there is no workaround for this.

More news as it's available, film at eleven....

73 KF8KK

2m Remote Base update

2004-09-10T01:12:00.000-04:00

I'm happy to report that a few more local frequencies have been added to the 2mtr remote base.

An updated 'Cheat Sheet' has just ben sent out with a listing of what's been added. (If you're not on the email list to get the 'Cheat Sheet', send me an email-- lookup KF8KK on qrz.com to get the email address)(I'd put the email here, but it'll get scooped up by spammers).

The VFO mode 'command prefix' has been changed to allow peole without the A-D buttons on their tone pads to access the command.

Sadly, it appears that the 'controller memory' channels don't properly set the PL encoder on the 2mtr SyntorX, this limits the usefulness of those memories and hence the number of local systems that I can program in. I have a partial workaround in the plan and hope to implement that in the next few days.

73 KF8KK

VFO Mode now functional

2004-09-03T01:55:00.000-04:00

I'm happy to report that the VFO mode for the 2mtr Motorola SyntorX remote base is now working.

Thanks to some specially configured programming by the 'XCat' (SyntorX pic based code plug) creator WB6YMH, the unit is now receiving commands from the Arcom RC210 repeater controller (using the Icom CI-v protocol).

While the commands to select the frequency/offset/PL are not hard to understand, they'll require their own page added to the 'Cheat Sheet'. I'll get a revised document sent out in the next few days.

Sadly, the interface is not perfect. It seems that the first time you enter the command for frequency/offset it just changes the frequency. If you need to change the offset also, the same command needs to be entered a second time in order for both the desired frequency and offset to 'take'. The PL programming seems to be fine.

73 KF8KK

Weather Receiver online

2004-09-03T01:53:00.000-04:00

The NOAA Weather receiver and alarm is back online as of tonight.

73 KF8KK

Weather Receiver offline

2004-09-01T03:12:00.000-04:00

While setting the audio levels on the freshly modified controller I disturbed the weather receiver (it needed the audio output cranked up just a notch to '7' from '6') and found that the stereo-sub-mini plug appears to have joined the ranks of the intermittant.

I brought the weather receiver home for some time on the workbench. Hopefully it will be back in service sometime this weekend (not a big job-- just a teeny tiny plug needs to be fixed-- not something for 'on site' maintenance, however).

73 KF8KK

Main controller online -- updates completed

2004-09-01T03:03:00.000-04:00

I'm happy to report that the Arcom RC210 now sports all the current audio mods recommended.

The controller was put back in service and should have more stable audio levels when the various links are turned on and off. I also added a 'click & pop mod' which should make certain audio switching smoother.

Additionally, the response resistors for the DTMF decoders were changed to values that supposedly make the decoders less prone to false decoding. Later this week the DTMF muting mode will be changed to allow just the first DTMF digit to pass through the system unmuted, while muting subsequent digits. This should virtually eliminate the annoyances of false DTMF detection. The 'mute on second tone' mode will also assist in Echolink disconnects-- as a single # disconnects an Echolink connection, and the # will then pass through the system without the user having to first disable DTMF muting.

Sadly, the new firmware for the Xcat (SyntorX 'code plug') that would allow it to listen in Icom CI-v mode for 2mtr VFO commands from the RC210 did not load as it should have and the 2m remote base still does not have a working VFO mode. I did perform the minor modifications to the SyntorX so that the data lines are all connected for Icom mode. All that's needed now is for the two computers to agree on baud rate and transceiver address and it'll work, the hardware is passing the data just fine.

More later... film at eleven...

73 KF8KK

Backup controller online -- updating underway

2004-08-30T20:57:00.000-04:00

Greetings!

Since today was an unusually 'slow ducky day', I decided to move forward the planned updating of the RC210 controller and swap the backup controller into the system for a day or two.

Until further notice the remote bases will not be functional. I expect to have the main controller back on site late on Tuesday, but perhaps it could be Wednesday.

Off to grab the gear and bring it to the workbench!

73
KF8KK

Scheduled Updating Mid Week

2004-08-29T15:32:00.000-04:00

Eff Wye Eye....

Sometime near mid-week the main repeater controller and the 2m remote base will be removed for some hardware and software updating. The repeater should be on the backup controller for about a day, perhaps two. While on the backup controller both 6m and 440 rptrs will be operational, but none of the remote bases nor ancillary functions will work, the voting systems will remain in operation.

The work will include some modifications to the DTMF decoders to reduce falsing, audio switcher mods to improve audio level consistency when remote links are turned on/off, a mod to prevent the phantom powering of the six meter rptr during times of power outage, and hopefully a successful fix for the VFO mode for the 2m synthesized remote base.

There will be another post on here when the switch to the backup controller is made (though it should be easily distinguishable on the air by the 'sound' of the repeaters).

73
KF8KK

Power Outage - Friday 8/27

2004-08-27T11:21:00.000-04:00

Harumph,

With a mass of thunderstorms passing through the area early this morning it was bound to cause problems. The A/C mains power at the repeater site is off at the moment and the 440 side of the repeater is functioning on battery backup.

Sadly, it appears that there was a phantom power backfeed path from the controller into the six meter Mitrek causing it to partially power up the Mitrek and continuously trigger false COS's from six meters. On the air this manifested itself as a continuous parade of six meter courtesy tones, holding the repeater in transmit.

The quick fix at the time was to pull the interface plug from the six meter Mitrek in order to return the 440 repeater to normal service. I'll break the phantom power path sometime in the next couple of weeks as I need to perform some other minor modifications on the repeater (DTMF decode issues, 2m VFO mode issues, etc).

This was the first time since the battery backup has been installed that we actually had a chance to make use of it (other than to cover up momentary burps in power).

Depending on the time of day that Consumers Power restores power to the site will determine how fast I can get up there to restore six meter operation. Worst case scenario would be that it wouldn't be restored until late this evening.

Otherwise, it appears the repeater survived this rash of storms unharmed. whew.

73 KF8KK

Remote base inactivity timer inoperative

2004-08-27T11:18:00.000-04:00

FYI---

Apparently the inactivity timer that turns off the remote base (either 2mtr or 220) after a half hour of inactivity has ceased to perform it's function. I suspect this may be related to the recent software update in the RC210 controller. Perhaps I can coax it to work again, or perhaps the latest update of software is broken. More info to follow as the story evolves...

73 KF8KK

RC210 controller updated to 4.28

2004-08-24T01:47:00.000-04:00

For those who might be interested in such things (and for my own records-- as this is the running log of repeater technical issues) the Arcom RC210 was updated to the 4.28 firmware today.

The data/clock for the 'Doug Hall RBI' frequency agile remote base mode still is not being transmitted by the RC210, but the data does get transmitted when in the Icom CI-V mode as it should.

73
KF8KK

New 220 link access code

2004-08-24T01:39:00.000-04:00

Sadly, last week when I updated the controller and the 'Cheat Sheet' I mistakenly programmed '22256' as the ON code for the link to the WB8DEL Stutsmanville repeater. The code should have been '22456' as that is in keeping with the codes for the other various links (the WB8DEL repeater is on 224.56MHz).

I've added a code to turn on the 220 link that responds to '22456'. The older codes, both the '22256' and '222#' will remain functional for another couple of months but will eventually be dropped.

73
John KF8KK

224.56 link operational

2004-08-24T01:30:00.000-04:00

The desense to the main 449.725 receiver from the 222.96 transmitter has been traced back to some internal mixing product leaking out of the units case. The problem was frequency dependent and it turned out that the 224.56/222.96 repeater pair just isn't too nice near a 449.725 receiver. Since the 220 transceiver was originally sitting directly atop the 449.725 receiver, I was able to almost completely (though not totally) eliminate the desense by placing the 220 transceiver in a different position in the rack. More work will ensue, but effectively the 220 link is fully operational (the desense present now is almost undetectable).

73
John KF8KK

Remote voting receivers installed

2004-08-22T21:40:00.000-04:00

The 449.725 and 52.42 receivers located at the W8TVC repeater site in Long Lake Township (3/4 mile south of Moomers and co-located with the 145.27 repeater) have finally been installed and made operational.

There may still be some tweaking to optimize their performance, but they appear to be doing what remote voting receivers do--- fill in holes in the receive coverage of the repeater.

Comments relating to whether they are voting for the best signal in an unbiased manner are welcome, as it is possible for the voting system to vote for the worse receiver when the adjustments are not quite optimized.

Should you find that the 449.725 voting system is voting improperly, you can force reception from the main repeater receiver by using a 151.4 hz PL tone rather than the normal 114.8 hz tone. The main receiver at the Glen-Arbor/Empire site has a second PL deccoder for the 151.4 hz frequency, which the receiver at the W8TVC location does not have such a decoder (just 114.8 hz).

The bi-directional link to the 145.27 repeater is not installed yet and due to be operational within the next few weeks.

The synthesized 2m remote base is functional in 'memory mode' only. VFO mode will be somewhat delayed as software problems need to be overcome. The current selection of channels in memory is changeable should different frequencies be desired, please let kf8kk know your thoughts on the frequencies in memory.

Sadly, there appears to be some interference to the main 449.725 receiver when the 220 link to the WB8DEL repeater in Stutsmanville is enabled. This interference manifests itself as desense on 449.725 and will cause the 220 link transmitter to pulsate when a signal is received on 449.725 unless the 449.725 signal is quite strong. With the addition of the remote voting receiver, this interference may not always be problematic (but that depends on your location). This appears to have started recently and may be related to the move in frequency of the WB8DEL repeater. Troubleshooting and repairs will happen soon. In the interim, please use the 220 link only when either within range of the receiver at the W8TVC site, or via six meters.

Finally, this blog has been created in order to notify interested repeater users of updates and changes to the repeater system. It will also be used to let people know of planned maintenance and other events that might effect the use of the repeater. For those with the capability, an RSS feed will be available shortly.

73 John kf8kk