At 03:47 PM 08/19/08, you wrote: > > if you run full time tone mode you can run open squelch > > (i.e. and blow raw carrier into the tone decoder) and > > maximize the system sensitivity. > >... with an advisory caution to use a serious quality >ctcss/dcs decoder. Less than optimal designed circuits >might false on or off.
Yep, I forgot to mention that (coming from a Moto environment, not a YaeComWood environment) > > This is because a weak carrier that otherwise wouldn't open > > the squelch will decode. > >The question is... would the now active weak carrier have an >honest usable voice quality signal? Is the difference worth >getting excited about? Probably not. Another trick - have the carrier squelch set so it requires a certain quieting signal - maybe 12-15db ... then have the tone decoder force the squelch open. > > If you didn't know it was toned you'd think it was a > > well-designed carrier squelch system (at least until the > > first YaeComWood showed up with it's no-reverse-burst and > > the PL reed in the system receiver had to freewheel to a > > stop to mute the audio). > >Wasn't GE's scheme to simply delay the carrier drop while >the ctcss went away... no reverse burst. Early GE, yes. When the Moto reverse burst patent expired GE came up (with a lot of marketing fanfare) with a great new invention - the Squelch Tail Eliminator circuit (called "STE" in the LBIs). I know that Mastr IIs have STE, not sure of the other series. >An early ACC Repeater Controller with the audio delay module >was a miracle cure-all for many would could not tame the >squelch crash noise gremlin. Yep. Easier to put a time delay in the repeater audio path than have every member build up a reverse burst encoder (or add an RB-1 to their TS-32). >s. I still remember the day that WA6KL:A and I had a conversation on a local 2m box, which at that time was Moto A strips with a factory PL decoder added on to an originally carrier squelch receiver. We both had U73MHT Motracs with reverse burst. Neil had rigged the repeater receiver squelch so that it required a decently quieting signal to repeat normally but a PLd signal would repeat even if it was a lot noisier. At that time I lived in the fringe area of the repeater, even for a 110w +3db gain mobile. I was maybe 1/4 to 1/3 quieting but had no squelch tail. Neil was full quieting and had no tail. Other hams had carrier squelch mobiles, could be line of sight but had a tail. It drove some of them nuts for months because they couldn't figure out what was going on. Mike
