Batboard

Shaun;

The Toronto Police have recently begun to install digital capabilites in it's Quantars (They run a 4 zone Smartzone system). All of the North Zone has been upgraded, but to date, nothing else has (yet). The audio on the North Zone sounds identical to that audio sample you posted (the click at the end), but the other 3 zones don't have it.

I don't know of any other 800MHz Astro capable SmartZone systems around here, but any other Astro system I know of doesn't do it - then again, they are Simulcast, not Smartzone, except the OPP system, but that's not 800MHz.

It could just be a coincidence, but...who knows.

-Mike

A true squelch tail is impossible if the system is running "PTT Trunking," since the receiver shifts to the control channel (with audio squelched) immediately upon detecting the disconnect tone (and while voice channel carrier is still up). It should be suppressed on "Message Trunking" by the shut-down of the "connect tone" about 135 ms before voice channel carrier shuts down.

This sounds to me like one of two things. On some Spectras, you'll get a good "chunk" out of the speaker both on unsquelching and squelching; this has something to do with the caps in the audio amplifier circuit. And on digital voice systems, I've heard reports of strange noises at the end of broadcasts, without a hint as to what is causing them.

Boy it sounds like the Connect Tone is cranked up. I don't know if its just me but it sounds like a PL tone with almost 2khz. deviation and you hear the "reverse burst" at the end of a transmission.

I've never heard anything like that in a trunked system before.

Mark

That is the sound of the button on the side of the microphone being released before the radio unkeys. I've heard this on several US-based systems.

oh yeah... "received"..

I may be wrong but it sounds as though the audio delay in the receiver-to-comparator-to-console and xmtr path is not enabled. This is what helps eliminate the connect/disconnect sounds in the sequence. Also sounds like the DPL steering level is set too high, if that's what's being used, or the line levels in the system aren't set right. This is the typical result if the audio line level of one of the stages in the path of the incoming received signal is low and the line level(s) after it in the path are cranked up to compensate. It happens quite often when a narrowband signal is patched to a wideband system for repeating.

I am unable to listen to that audio file, so I am going on what others here have said.
Some speaker mics have a button 'clunk' as the button is relaesed, typacal on Jedi s/m's. The portable radio's transmitter is still on and the 'clunk' gets passed along just as the transmitter is sending the turn-off code or 'reverse burst'. Sometimes the compensation is incorrect on the individul radio causing an increased low frequency deviation.. loud PL tone, ect. I found setting the compensation correctly would reduce the 'clunk' sound some.

I even took the PTT button off the speaker mic and added some TB20 inside of the hollow button to reduce the 'clunk' noise from the button.