Re: Squelch crash on a MSR2000 (Squelch Adjustment) > "kc7stw" <kc7...@...> wrote: > Hello again. > > I have a UHF MSR2000 up and running now. Most of my radios have > the reverse burst in them. But just about all ham grade radios > do not. Is there a way to get rid of the squelch crash from > the repeater when a non commercial grade radio is used? > Repeater is stock, and would like to try and keep it that > way. Hoping there is maybe a jumper setting or a trick that > someone might know. > Single PL tone card in the repeater, card number trn073app on > back, trn5073 on front. > thanks
The MSR-2000 normally has two user accessible squelch pots, one on the R1-Audio and the second on the Squelch Gate Module. There is a quick way... The R1-Audio Module Squelch is the one you want to address, simply turn it up just a little bit until the squelch crash stops. The real alignment is something like allowing the repeater to transmit by rotating the Squelch Gate Module Squelch CCW and applying a weak signal. The repeater should key on with enough weak signal. Also rotate the R1-Audio Squelch all the way open (CCW). You then pick a value of signal near the noise where you want the repeater audio path to open and with the repeater keyed on and passing signal, increase the R1-Audio Squelch until the audio gates (turns) off. The repeater should/will remain keyed. As an example, pick .20 uV (micro-volts) where the receive signal might be noisy enough so signals below that value would be considered something you don't want hear. Set the R1-Audio Pot to close/gate the repeater tx audio off when signals fall below your chosen value. Onward, Then select a slightly lower signal value for the Squelch Gate Module to key the repeater on/off before the audio path opens. Using the .20 uV value for the audio path, one might select .15 uV as the Squelch Gate Module (squelch pot) value/position. The resultant operation is the repeater starts to transmit at .15uv (super noisy) and the audio path will open at .20 uV The process works in reverse and when properly set up as described above, one should not hear a squelch crash under any normal condition. The MSR-2000 operation should be considered fast, clean and result in professional quality repeater audio when properly adjusted. Reverse burst and tone filtering is supplied by the PL or DPL module you mentioned you don't yet have. Regardless you shouldn't hear received user signal squelch crash noise if you have the R1-Audio and Squelch Gate Module pots properly adjusted. You can play with the R1-Audio Squelch pot when you first encounter its setup for the first time to hear various examples of the various R1-Audio Squelch pot adjustment points. At some squelch pot value close to the audio open squelch (un-squelched audio path) point you'll start to hear the crash noise with receiver activity. As you travel to-far toward the "tighter" (clock wise) pot direction weak signal activity might not open the repeater transmit audio path early enough and is mostly noticed by portable users audio turning off (muting) as their signals rise in and out of the noise (usable signal levels). When properly adjusted, the "dead-band" area where the repeater keys (transmits), up to the level where the R1-Audio squelch opens the transmit audio path will/should be a noisy pretty much unusable received signal place. The transition speed is so fast the end result is normally any user selected (you choose) voice audio signal level and higher is allowed to pass through to the transmitter. The squelch gate module circuit will detect signal levels well into the noise before any real usable audio value is available. So the repeater comes on the air before the audio is usable and at your choice of usable audio level the audio path will open (become active). When the R1-Audio squelch pot is not adjusted "tight enough", you'll hear a crash noise with regular receiver activity. Quite different from the Micor Squelch but also resulting in a very clean crash-less audio operation when properly adjusted. Just more user adjustment pots to set for a real "season to taste". cheers, s.
