Batboard

We use a MOTO TRBO system at work and only have three different talkgroups. One is typically used and the other two are very rarely used. Usually, if I want to transmit, I press the PTT switch, hear the Talk Permit Tone, and life is good. Occasionally I get a different tone, I am not sure of the correct terminolgy, but I suspect it is Channel Busy or something along those lines. Anyway, what will cause that tone to be generated? I realize that if another conversation on our talkgroups were in progess I would likely get that. Also, if I understand MOTO TRBO correctly, we should be allowed to have two completely separate conversations on different talkgroups simultaneously. In this case, that is not likely happening. So, does something like the IDer capture both channel paths until it completes its identification or is there likely to be something else causing this. I am a little bit nervous (from an officer safety standpoint) to get a busy signal for just a CW id'er, if that is what is happening.

Also, I apologize ahead of time for what is obviously a very elementary question. I must admit that I "cut my teeth" in the digital world on a statewide 800 mHz APCO P25 system, which, as many here already know, operates very differently than MOTO TRBO in many respects. Also, the extent of my radio training on MOTO TRBO has pretty much been: turn it on, select channel, talk, etc.

There could be a few things going on. If it is indeed a channel busy (repetitive 'bonk', much like a busy phone line sounds), it would show that on the screen...unless you don't have an LCD model.

First, even though the repeater has two slots & is capable of allowing two simultaneous conversations, if the radios are all programmed to only use 'slot 1', then the other slot isn't being used. You'd have to read the radio to figure that out. Sometimes this is done to accommodate the 'All Call' feature, which is slot specific in conventional mode...it won't reach radios sitting on the other slot. Or, the programmer just didn't understand how TRBO works.

Another thing that could be an issue is the radio is programmed with "channel free" as the admit criteria, and the threshold is left at the default of -119dBm. This means just about any sort of background RF noise will cause the radio to think the channel is in use & you won't be able to transmit. Much better to set it for "color code free" where it needs to see a proper digital stream before it'll consider it valid & not allow transmit.

Lastly, is there any GPS/telemetry/text messaging going on? Text & telemetry take place on whatever slot the radio is sitting on for voice & can cause busies. For GPS, even if it's set to revert to the other slot to send it's location update, all the "ARS" (automatic registration services...power on, power off, channel change, etc) take place on the voice slot and if there are a large number of radios in your system it can certainly cause issues with busies.

That is good information to know. Thank you for the reply.