nm9stheham
Newbie
- Joined
- Feb 5, 2014
- Messages
- 1
So we are working on a jail upgrade for a repeater driven distributed indoor antenna system and one thing is popping up that is new to us. When you key up on a radio, most of the time things are fine; the call is set up on the nearest Astro P25 simulcast site that is donoring to the jail repeater. But sometimes, instead of audio, you hear just a raucous squawk. If you hold the key down on the portable TX and continue to hold, it never clears up; it stays this way 'til the call times out, even if you walk around to and fro to vary the signal levels through the DAS/repeater. The squawk sounds like the very early TDMA cell phones with the early vocoders that got really crappy sounding when there was interference, or the call got too weak. It sounds like the vocoder data framing is getting all screwed up. Downlink signal levels are in the -90 dBm or hotter range when this occurs.
So, does anyone here have the experience to know if is this normal for non-TDMA P25 Astro portables, to have these types of occasional squawking-call issues? We have not yet tested outside direct on the simulcast system; only through the jail repeater. (The repeater is an Andrew/Commscope Node A unit set up in channel selective mode to suppress some nearby SMR interferers; it does well in that task.)
If it does happen on ohter systems, are there a particular set of circumstances in which it likely to occur?
So, does anyone here have the experience to know if is this normal for non-TDMA P25 Astro portables, to have these types of occasional squawking-call issues? We have not yet tested outside direct on the simulcast system; only through the jail repeater. (The repeater is an Andrew/Commscope Node A unit set up in channel selective mode to suppress some nearby SMR interferers; it does well in that task.)
If it does happen on ohter systems, are there a particular set of circumstances in which it likely to occur?
