At 10/22/2009 12:01, you wrote:
><mailto:[email protected]>[email protected] wrote: >> >>At 10/21/2009 13:23, you wrote: >> >> >> >>> >>>Anybody got any suggestions about fixing the squelch circuit? (Spare me >>>the get a REAL repeater comments please!) >>> >>> >>> >>>Is the MICOR squelch still available? Anybody done it to one of these? >>> >> >> >>I added a Micor squelch board from LinkComm to a Kendecom RX once. It >>worked fairly well, though it was still somewhat susceptible to off-channel >>signals, making the squelch excessively tight whenever a strong signal was >>present 15 kHz away, regardless of modulation level on that signal. I >>suspect this to be due to design flaw in the MR4 design (mid-stage IF >>amplifier overload). A 10 kHz LPF in front of the Micor squelch board may >>cure that problem. >> >>Bob NO6B > >Funny you should mention that, Bob... The Kendecom repeater the local >club had would indeed overload. If you were within a mile of the repeater >site and forgot to go to low power on the mobile rig, the repeater would >remind you - by cutting you off. If you reduced the power level on your >radio to 5 watts, you could use the repeater almost right up to the >site. This is the only repeater we have utilized at that site that >exhibited this behavior. It was replaced about 7 years ago with a 30 year >old MICOR. > >Kevin Custer The built-in Kendecom squelch is rather odd in that it is a bilevel squelch, but IIRC the fast squelch is activated not by noise, but by an RSSI indicator that comes from the 1st IF, not the 2nd. As such, it's susceptible to adjacent channel interference since it sees adjacent channel energy that makes it through the 1st IF filters. The problem I described with the Micor squelch is unrelated to this. In your case, I suspect a simple misadjustment with the fast squelch circuit, as it sounds like it completely cut off the squelch when it was activated. Bob NO6B
