Inconsistent key-up activation with MD-390

MMDVM_HS Hat hardware
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kd2jal
Posts: 2
Joined: Fri Mar 01, 2019 9:52 pm

Inconsistent key-up activation with MD-390

Post by kd2jal »

Hi folks. I've about exhausted the limits of search so I figured I'd turn here.

I have an MD-390 (running the TyMd280Toolz firmware) and Pi-Star running on a RPi Zero W with a N5BOC duplex MMDVM modem. Pi-Star is at version 4.1.4, and the modem is running v1.5.2 (but this issue also occurred with v1.4.16)

The behavior is this, very often I key up the MD390 to activate the hostpot, the red PTT LED will light up on the modem, but the radio does not negotiate and I get the "bong" tone of the radio telling me so. The log shows the following:

Code: Select all

Downlink Activate received from KD2JAL
The log does NOT show

Code: Select all

"received RF voice header"
as you would expect. If I try again it may happen several times, as many as 10 times even. Eventually, it will negotiate and work fine. It may work fine for an entire QSO, and then it'll happen again randomly.

I only have this DMR radio so no other modes are enabled. (I’ve heard that could affect things if it’s trying to detect another mode)

I know what you're saying. BER, Calibration, etc. Here are some troubleshooting steps I've taken:

1. I've calibrated my TXOffsets using this method and Imy TXLevel with an SDR using this method. My BER is usually under 0.5% and ver often it is 0.0%

2. I've moved away from the repeater just to make sure it wasn't an issue of testing too close and de-sensing.

3. Updating MMVDM firmware versions, as mentioned, this was a shot in the dark but the update didn't fix anything.

4. Starting from a factory Pi-star configuration, in case I fat fingered some setting somewhere (there are a lot of them)

I'm out of ideas and figured I'd see if there was a logical next step. Most of the traditional troubleshooting here has to do with reducing BER... but I see a very low BER when I do get a voice downlink to negotiate, so I don't think its that and I'm stumped.

Thanks for your time.
73,
Jake
kd2jal
Posts: 2
Joined: Fri Mar 01, 2019 9:52 pm

Re: Inconsistent key-up activation with MD-390

Post by kd2jal »

In case anyone else sees this issue:

I found this post: https://github.com/juribeparada/MMDVM_HS/issues/63

Bumping up the DMRTXLevel setting seems to have improved my situation.
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