"Jay in the Mojave" wrote in message
...
Hello Brian:

The Smart Squelch is supposed to be smart, just as its said! That is the
squelch will open or turn on the receiver audio when a signal is
received in the receivers IF. A separate pick off of the IF RF is
sampled and then its supposed to only open the Squelch when there is a
real signal, and is not supposed to work on noise, bleed over, static
and such. The Smart Squelch is supposed to be able to discern between
noises and a real RF signal. And its advertised as having a very high
percentage of success, being able to only open the receiver with a rf
signal and not noise.

I built a Analog Smart Squelch back in the 80's for my Motorola System
500 Mobile SSB/AM CB Radio. (which all ready had a active Motorola noise
canceling circuit in the IF Section) It worked real well. It was great
driving down the freeway and not hearing motor noise, like setting at
home. The Smart Squelch came from a article in a magazine, and I bought
the kit and put it together.

But this new circuit is supposed to be digital. I haven't seen it yet.

But I know a lot of guys are using the Heil, Alpha Delta, and others
External Speakers with DSP for extra noise cancelling. I have a Heil DSP
External Speaker, and it works great, just need a smart squelch to go
with it.

Jay in the Mojave

Telstar Electronics wrote:
Jay in the Mojave wrote:

I have a good friend on 40 that is going to send me a custom circuit
that is supposed to do all this, and has a smart squelch to. We will see.


Smart squelch? Please explain...

www.telstar-electronics.com


I remember something that use a "bucket brigrade" audio delay line in a
sqeich circuit in late 70s or early 80s. The audio was delayed a few
milliseconds so the hardware would have time to analyse the signal to see if
it should be squelched or not. Is this what yu are talking about. Probably a
piece of cake for DSP.

My first experience with DSP was in the Air Force. I was sent to school on
this new modem and endured a month of theory on how modems worked all built
around analog devices. In reality this thing was just a RISC computer
attached to D/A and A/D converters. The only thing analog about it was a
couple of op amps used on the input and output.. The modem itself was tiny
but the cabinet it was in was huge. I guess it had to be this way for all
the human interface that was needed.