I am a very big fan of the Micor bi-level squelch. It's action is second to none on my 440 and 900 system however, I too am having the exact same problem on my 29.540 receiver in carrier squelch. I just will not take anyone into the noise but rather near quieting signals just "pop out" and disapear under the squelch. I have tried cleaning all of the pins and swapping out the audio control module but nothing seems to help. Interesting enough, this is NOT happening on my 6 meter Spectra Tac!
At the moment, I have placed my 29.540 Spectra Tac aside and replaced it with a GE Mastr II auxiliary receiver on 10 meters. The results are much better as pertains to the squelch, but this is not to start a Micor vs. Mastr II comparison.....something is just not right on 10 meters with a Spectra Tac receiver. If it can work on all of the other bands (especially six meters!) it should work on 10. If anyone has any suggestions, perhaps some part changes on the audio control module, they would be greatly appreciated! Adam N2ACF kq2h wrote: > I've been impressed with the operation of the Micor bi-level squelch circuit > based on the M7716 IC. I use Micor Spectra-Tac receivers exclusively on 440, > 902, 6 Meters and 222 MHz (VHF to 222 conversion) with excellent results. > However, I am perplexed by 10 Meters. The Spectra-Tac squelch circuit doesn't > work well at all. It squelches up on fading signals that aren't all that > noisy and drops out for no apparant reason. It appears that the squelch is > set too high, but it isn't. I've tried different audio/squelch modules, > receiver boards and housings. Even the IMTS modification which defeats the > short squelch tail doesn't help the situation. When a UHF reciever is > substituted in place of the 10 Meter receiver, the squelch circuit works > fine. > > An old 25-30 MHz Motrac receiver, with its simple 3 transistor squelch > circuit, works perfectly on 10 Meters. There are no problems with drop outs. > The receiver squelch remains open well into the noise. This leads me to > believe that the Micor bi-level circuit needs to be optimized for 10 Meters. > > Does anyone know of any component value changes in the Micor bi-level circuit > to optimize operation on 10 Meters? > > > > ------------------------------------ > > > > Yahoo! Groups Links > > > > >
