On 5/3/2010 12:08 PM, N1BUG wrote: > I'm guessing I am not the first to want to do this... > > I want to use a UHF Micor for a link. I want to be able to stop the > PL encode immediately when a user unkeys, but I want the controller > to be able to hold the transmitter up (without PL tone) for sending IDs. > > There appears to be no PL on/off gate on the TLN5731A encoder. The > only tone gate is Q703 which only gates the out of phase tone used > for reverse burst. > > Other than using a mechanical relay to interrupt the encoder tone > output, any suggestions? > > Thanks, > > Paul N1BUG
The usual method we've used is to pull it to ground when you don't want tone with a transistor or a FET. You can remember though that, depending on your link rx, letting the Micor encode reverse burst will close the squelch quicker than just letting it coast. My experience is that the reverse burst on the stock Micor encode board works on the vast majority of radios, both Motorola and not. It worked on every Kenwood I had except for the old TK-801. Ham or commercial. The only other radio I have had in recnt years that it did not work on is the Yaesu VX-1R. Not even "chicken burst" works with that radio. I can't say for sure, but I think that if you key it with the PTT input, after the reverse burst delay, the tone will shut off...I could be wrong though...I'm sure there's a simple way to do it though. A one-transistor switch in the right place shoule do it.
