September 26, 2004

Miscellaneous update September 26

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


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

September 14, 2004

RC210 Controller back online

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


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


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

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

September 10, 2004

2m RB VFO mode PL encoder inoperative


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

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 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

September 03, 2004

VFO Mode now functional

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

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

73 KF8KK

September 01, 2004

Weather Receiver offline

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

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