Thursday, October 6, 2016

PCB soldering and testing MMDVM

Well got couple boards assembled and started testing digital modes on the MMDVM hardware and software. the SP8nth board works nicely and i made some modifications to suit my use better, (change of some resistor values etc...).

So far its working decent, once I was able to get the audio levels calibrated. DMR has been working great talking on the national Talkgroup TG3100 on the Brandmeister network.  I am using a Kenwood TK-860H that I modified for ham band use and made the custom accessory cable to access the data audio input and discriminator audio out. 

on the Yaesu Fusion side its been working pretty good as well... been connecting to the Alabama Link reflector and been able to monitor QSO's easily, and tested some transmissions and so far no dropouts of audio.

The level on the output of the MMDVM is at mic level and the Kenwood DI (data input) likes to have line level audio so i had to add an outboard audio amplifier to boost the modulated data to get the right level and deviation to support digital modes. so far I only tested it with the Kenwood radios as that's all I have, and looking to get a couple Motorola GM300 or the 1250 radios used cheaply as many others have had great luck with MMDVM...

more updates soon...
73's WV8TIM

1 comment:

  1. Hello! This is Rick, LU9DA from Mar del Plata, in Argentina. I working on interface my zum board to a KW TK860H and find the same problem, low modulation level... can you tel me what kind of amplifier are you using?


    Rick LU9DA