can't hear most transmissions. why?

do1jml
Posts: 53
Joined: Fri Sep 11, 2020 10:56 am

Re: can't hear most transmissions. why?

Post by do1jml » Tue May 11, 2021 6:21 am

OE2WHP wrote:
Wed May 05, 2021 7:22 pm
I can hear some OM's but quite often,the green LED comes on, indicating some activity but I can't hear anything. I tried monitor mode (promiscous mode) on as well but that doesn't change anything.
There may be non-voice activity on the repeater. A check on the local repeaters with a SDR shows them to switch on from time to time, sometimes for half a minute or so. It is also possible to switch them on by using non-voice functions on the GD-77, for example "radio check".

ok1pt
Posts: 167
Joined: Mon Jul 20, 2020 3:38 am

Re: can't hear most transmissions. why?

Post by ok1pt » Tue May 11, 2021 9:33 am

OE2WHP wrote:
Wed May 05, 2021 7:22 pm
I can hear some OM's but quite often,the green LED comes on, indicating some activity but I can't hear anything. I tried monitor mode (promiscous mode) on as well but that doesn't change anything.
Hi!
Here in Czech Republic, DMR repeaters operated by emergency services (Ambulance, Fire Brigade - Police uses TETRA) are keyed on very frequently - at least 30 seconds per minute - but you can hear voice once or twice per hour. Most of the information are data packets, i.e.
- SMS
- GPS coordinates of mobile stations sent about three times per minute (when moving)
- repeater beacons, reachability checks by mobile stations etc.
OpenGD77 is just silent, which is moreless perfect - for example, letting Anytone AT-D878UV receive such a repeater leads to a total freeze of the radio software in a few minutes - you must remove the battery to restart.
I believe that it's very similar in your case.
WIth regards / 73,
Pavel

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