DMR MMDVM does not see my radio

Help with DMR issues
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Joined: Fri Jan 17, 2020 8:38 pm

DMR MMDVM does not see my radio

Post by KL6M » Mon Feb 10, 2020 10:37 pm

I have a Pi-zero-w and a MMDVM I got on Ebay for $18.98 from, you guessed it, China. I cannot get the radio portion to work. The MMDVM does not respond to my radio TX. I have Pi-star running and have checked and rechecked all configuration entries and see nothing wrong.

My MMDVM has a STM32F103 and ADF7021. On the Admin page it detects the hat as FW HS_HAT:v1.4.17. I selected modem type STM-DVM/MMDVM_HS-Raspberry Pi Hat (GPIO).

It boots up with all the LEDs flasing and settles with green power on solid and rapid flashing red SVC. If I press reset button on the hat, the red flashes much slower.

I changed TX & RX frequencies on both Pi-star and my radio from 446.5 to 433.2 which made no difference.

I fiddled with a few RXDCOoffsets and RXOffsets in Pi-star expert with no luck. I checked the TCXO frequency with a counter and it measured 14.74556, so only 40Hz low. I also checked frequency on my Retevis RT3 and it is only 20Hz low.

Any other ideas? Pleeeeeze? [email protected]

Posts: 16
Joined: Sat Dec 14, 2019 3:31 am

Re: DMR MMDVM does not see my radio

Post by VK3HAW » Wed Feb 12, 2020 5:26 am

Had any luck? You could try changing the RX/TX offsets by -150 at a time and see if it starts hearing each time, maybe go as far as -1000.

This post may help viewtopic.php?f=5&t=1983

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