gregmrfs wrote: > Hi Everyone, > > I have been tasked with programming and installing a UHF quantar by > my local amateur radio club. I got it on the air tonight. The P25 > side appears to work fine, however the analogue side has some annoying > static at the end of the TX audio, just before the tails drops. > > Basically it is just as the person dekeys, there is a split second of > static prior to the tail dropping. The tail drops clean. > > The unit is programmed with a 123Hz tone and 293 NAC. > > Any help on removing the static would be appreciated. > > Thanks > > Greg
ummm-it's called a "squelch burst" or "squelch tail" or "squech crash" by most. It takes a short period of time for the squelch circuit to mute the receive audio, so a brief 'burst' is normally heard. To eliminate it, there are two main methods: -All the users use commercial gear that has 'reverse-burst' or 'squelch-tail eliminator', which inverts the phase of the CTCSS tone for abt 100-200 mS after PTT is released and before the transmitter unkeys. Anyone using a 'made-for-ham' rig will still have the 'tail' -Install an outboard controller that has an audio delay circuit of some sort in it. It delays the audio by abt the same 100-200 mS, but mutes the repeat audio path instantly, closing the gate before the signal goes away.
