Will an Astro receive with a broken tx? (trunking)

[Elroy Jetson]

Just curious about this.

of course there is some interest in people having an Astro working as a
"perfect scanner" on such sophisticated systems as a fully digital SmartZone
system. And there have been many methods tried to get the radio to truly
be quiet and not announce its presence to the system in any way. Full "stealth mode".


I'm not in a position to do any such explorations, but I wonder...if you had
a fully programmed Astro on such a system and the transmitter in the
radio was incapable of operating (say it has a bad PA driver), would the
radio be able to receive despite the lack of ANY transmit capability whatsoever?

I'm just not so clear on how important it is for the radio to get an acknowledgement of a login or status request.


Elroy

[Victor Xray]

Probably not, especially if it's of the ASTRO25 family, as all those radios must affiliate before they start to receive.

[mr.syntrx]

Yeah. In SmartZone mode, the radio will just say "OUT OF RANGE", even if it can hear the CC.

[Pj]

OBT radio's seem to be more picky, but we had a 800 radio that had a bad PA (ASpectra) and still would see the TRS. I don't think anything with real power was getting out, especially with the distance to the "local" tower. I'd find it difficult that the system heard the bad order spectra.

HRR Astro spectras WILL properly track a SZ system without ever AFF. Of course, if there is no activity on the selected talkgroup out of zone, your not going to hear anything...but all the SZ side feature work (RSSI, site alias, etc).

As for the Sabers and XTS3k's, I'd imagine they could work the same way, since the operating principles are very close.

ASTRO25 is another story, but would be interesting to see if the "bad pa" trick would actually work. I don't have access to a ASTRO25 system, so can't help you there.

[wavetar]

Here's what I've found over the years with a 'fair-to-middling' amount of testing:

XTS3000/Astro Saber/ Astro Spectra - If the PA is bad/disabled/whatever, these radios will constantly scan through the control channels, not stopping on any one for more than a few seconds. However, if it happens to see valid talkgroup activity on a site while it happens to be sitting on it, it will then "settle down" on that site & appears to remain there indefinitely, or until the radio goes out of range/turns off/changes channels/whatever. On a fairly busy system with lots of talkgroup activity on the towers near you, you may not even notice there's an issue. Bellersly has noted that using "site lock" works well in this scenario.

Astro25 radios (XTS/XTL1500/2500/5000 series) - Well, since we have a real problem with XTS5000 PA failures on our own 3600bps system, I can readily attest to the fact the radio will not work if it cannot tx to the system. I have seen a couple of different errors come on the screen...sometimes it'll say "no comms", other times it'll say "out of range". I assume it would be the same for 9600bps systems as well, but cannot test it to verify.

There's much of the same info on your old "hidden groups" thread, Elroy:

http://batboard.batlabs.com/viewtopic.p ... 2&start=50

Todd