[EMAIL PROTECTED] wrote: > There is no 'reverse burst decoder' per se in a tone decoder - it is > just driven with the out of phase energy long enough to cause it to > close very quickly. All tone decoders react to the reverse burst, not > just one that is specially configured to react to a reverse burst. I > don't know of any special circuitry in a tone decoder that makes it > more susceptible to a reverse burst than a normal tone decoder. > > 73 - Jim W5ZIT
The cheaper decoders that don't have good 'talk-off' immunity will have a delay cap in the output to keep it open for a period of time no matter what. Some of them are so long that even 'chicken-burst' won't work. Even the early TS-32's were like that. Many newer 'decoders' are actually in software/firmware in the radio, and sense the phase inversion in S/W. In fact, many new radios do everything in S/W except the actual RF filtering and amplification. Feed the high-IF in one pin, get audio out another. -- Jim Barbour WD8CHL
