Over modulation?

Help with D-Star related issues
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Joined: Tue Apr 24, 2018 5:34 pm

Over modulation?

Post by G4AON »

I'm not certain, but it sounds like some "loud" stations break up with a "beep" while otherwise being a good signal. This seens to be more of an issue with an MMDVM board than a DVAP dongle.

In the MMDVM config (Expert, Edit MMDVM Host), there are several level settings that by default are all "50", which I guess means 50%. Reducing those to 30 seems to reduce the break up, but not entirely clear it. Reducing the levels below about 30 seems to stop things working...

I haven't altered the DC Offsets but have the RX and TX frequency offsets set pretty close to optimum and obtain less than 0.5% BER on DMR.

Anyone been there and fixed this issue?

73 Dave
ID51E plus 2
AnyTone AT-D878UV
Chinese MMDVM on a Pi Zero W
DVAP on a Pi 3B
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