OpenGD77

Could use help solving a problem.

I’m listening to an analog net on a repeater. Someone is speaking, good strong signal and audio, with the RSSI indicator bar at around 75%. That person transmitting completes their conversation and there’s a second of silence (squelched). The next person begins speaking, but their signal is poor, “staticky” and weaker, maybe 45% on the signal bar. If I change the channel and come right back, the second person is still speaking and their signal now sounds better and indicates 75% on the signal bar.

It seems that the receiver signal level is low when breaking squelch, but fine when tuning to an analog channel. Is this a hardware problem, a software bug, or a setting issue?

Thanks.

I have never observed that behaviour. However even a signal level of 45% should still be a good signal. So it sounds more like some form of interference or frequency error. The squelch closing and opening should not have any such affect.

If your radio is entering power save mode between transmissions then it might not be starting up correctly.

What eco level are you using?
Does the problem still exist if you set level 0?

Colin G4EML.

Its definitely worth switching Eco Level to 0, to disable it

However 1 second latency would be very strange for the default Eco Level of 1, as power saving is does not start for at least 10 seconds after the last signal ends.

Also. Another test would be to try an older version of the firmware eg. The last 'stable' release or the 'stable' release last October

Still having the problem. Here’s a video demonstrating it.

https://www.dropbox.com/s/zhusm6gho5cfb ... 4.MOV?dl=0

WA0YCN wrote: ↑

Fri Mar 19, 2021 1:36 am

Still having the problem. Here’s a video demonstrating it.

https://www.dropbox.com/s/zhusm6gho5cfb ... 4.MOV?dl=0

I just tested this, but I can't replicate the problem demonstrated in the video.


Do you get the same problem using the VFO?

I am trying to reproduce your problem but have also been unable to do so.

Some questions so that we can progress this some more.

What ECO setting was being used? If I was anything other than 0 please try again with 0.

Was the radio using an external antenna or a whip antenna?

The S Meter level seems very high with with no signal, what does it read with no antenna connected?

73
Colin G4EML

After some more experimenting I did manage to reproduce something like what you are seeing. However it involved feeding a strong interfering signal on a nearby frequency into the radio along with the wanted one and only occurred with careful adjustment of the relative levels.

Do you have any other strong signals in your location? For example another repeater or a local FM broadcast transmitter. The chip used in the GD77 is known to have problems when used in such an environment. Such problems can sometimes be improved by reducing the signal level being received. Either by using a lower gain antenna or by adding an attenuator.

Colin G4EML

I think its also necessary to test the same conditions with the official firmware, because although the official firmware does not have a usable S meter, the signal can be audibly heard to be weaker when the station re-transmits and this effect may be audible in the official firmware

ECO setting is 0.

Experienced problem with both external and whip antennas.

S meter is zero with no antenna.

No strong or interfering signals in the area.

Originally switched to OpenGD77 because I thought I was having a squelch problem with the factory firmware (only two squelch levels) because while scanning, when the radio detected an active channel it wouldn’t keep the squelch broken. Now I realize it was essentially the same as what I’m seeing now with OpenGD77.

Are we thinking it’s a bad radio?

It does seem to be a strange problem.

It looks like the RF chip may be faulty.

We've also sometimes seen strange problems caused by dry joints, but the dry joint , intermittent weak signal seems to happen when switching from Tx to Rx, though it was similar to the the problem you are seeing