--- In [email protected], "Thomas Oliver" <tsoli...@...> wrote: > Tom, the receiver and squelch appear to operate normally when using a service monitor to generate signal. Noise floor issues can certainly be a problem, although a Motrac receiver works fine on the same exact antenna. It's getting blasted by the same noise...
> I wonder if it is a noise floor problem. How does it act on a service > monitor when it is not hooked to an antenna picking up high levels of noise? > > tom > > > > [Original Message] > > From: Adam Feuer <feu...@...> > > To: <[email protected]> > > Date: 7/12/2009 7:30:11 AM > > Subject: Re: [Repeater-Builder] Micor Bi-Level Squelch Circuit > > > > 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 > > > > > > > > > > > > > > > > > > > > > > > ------------------------------------ > > > > > > > > Yahoo! Groups Links > > > > > > >
