Friday, October 7, 2016

Good day testing

Well today was a good day and after a week of playing around with settings adjustments etc I had two good QSO's one on DMR and one on YSF, so far i had no reports of dropouts in audio and reception was good too... I still have a little bit of tweaking on the receive side as I occasionally will get a small drop in audio or digital garble. I was able to confirm that today on the System Fusion side while listening to a reflector off of the internet where the internet didn't drop and my radio had a couple blips. Not sure but may also be my Kenwood radio and hope to get one in from a different manufacturer soon and go back to the test bench.

more pics and details to follow soon on what I did and how I got it all working.


Thursday, October 6, 2016

DMR in action

Here are a couple pics of the MMDVM working in DMR mode and showing reception on a TYT MD-380 Radio..

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