Batboard

Maybe you all can help my understanding of the new digital trunked networks? Here in Baltimore MD, ALL of our PS use the 800 Mhz digital network now (and use XTS3000 type radios). I've been content to listen to the simulcast of fire/ems dispatches on VHF, but I'm interested in hearing the police now.

If I were to buy a used astro saber, even the model 1, could I use this as a scanner (actually, a monitor), programmed correctly? I know that the new digital scanners can listen in, but sometimes the used astro sabers are cheap and I'm also cheap...

It was my impression that every time a radio is added to the network, the control unit (or whatever you call it) knows it because the radio begins exchanging info on the control channel. And then they can disable the radio remotely. Is that correct? Yet if you get one of the digital trunktracker scanners, obviously this can't happen.

So, is trying to listen in with a real motorola transceiver a bad idea? or feasible? what if the tx were disabled?

thanks for your expertise!

Just go and buy a digital capable scanner. It will be a lot cheaper. Wait until the new Radio Shack scanner comes out. It should be able to monitor 3600 and 9600 baud Astro systems. Buying the real radio and getting it programed will cost more in the long run.

My rule of thumb for people asking about getting a digital RADIO vs a digital SCANNER is this:

Do you have a NEED (work, pleasure, whatever) to operate in the digital mode?

If not, what costs less, the scanner or the radio?

If the radio, did you factor in the extra costs of: The RIB, the cable, the cost of the software?

If no, will your local MSS program the radio for you?
-In case of a trunking system, figure NO unless you know someone who works there and is willing to lose his job.

Is it worth the hassel if stopped by the cops?

In most cases, the scanner is the better option, and you won't have to deal with the programming issues and possiblilty accidently transmit on the system. In case of trunking systems, you cannot lockout the PTT. Yes there is a way around it, but generally (I find) people just program them up as normal radios.

ok, this advice makes sense. I'll probably wait for that radio shack model to come out this fall...

but a question about this:

If no, will your local MSS program the radio for you?
-In case of a trunking system, figure NO unless you know someone who works there and is willing to lose his job.

why? Is it illegal to program radios for that purpose?

Well, I being really technical and legal, I think there is a FCC reg or something that says no. However, MSS shops usually have contracts and legal obligations with their customers that prohibit the release of such information, etc. Also think of the liability. I program your radio so the state police's trunked system. You decide to get crazy and start keying up the radio and create all sorts of havoc. A troopers call for help doesn't get thru due to busy signals or whatnot, and they find out it comes back to you (yes there are ways)....Where does that put you and the MSS? Big time legal hot water.

Also on the flip side..... Say you lose your radio and someone picks it up and starts to play with it. Its happened several times with legit radios...

To add to the foregoing (the conclusions of which I agree with): if you buy a public safety grade radio for use as a scanner, you are likely to be disappointed, since the scan list in virtually every trunked Motorola portable I am aware of is limited to 15+1 "channels".

Yeah, forgot about that. Also, if you use it to scan a trunking system, you are usally limited 10 members in the scan list, which REALLY sucks especially if want to scan multiple talkgroups in multiple systems. 10, and that's it.

Not to kick a dead horse, but in any radio -- public safety or consumer scanner -- if you try to scan a list that includes trunked talkgroups on different "systems" (where for present purposes I define a system to mean a combination of a control channel and SysID), there is a large but not often recognized penalty that one should be aware of.

A trunked radio does not scan but sequentially testing a list of discrete frequencies. Rather, it parks on a control channel for a set period of time and listens to the data, following group talk channel grants for any talkgroup that is in its scan list. Usually, the amount of time it parks on one control channel is X seconds of silence, which means that if a listed channel grant comes up within X seconds, the timer is started again.

Here is the critical point: while the radio is parked on one system's control channel, it cannot hear or know anything about any other system.

So you can have a huge audio hole, missing valid traffic, even though the radio is quiet.

Hence the rule when programming radios for public safety uses: never mix systems in a scan list.