220 remote base repaired
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
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