Home Brew Dstar - DV Node Adapter

For those interested in home brewing and Dstar, Pictured right - Michael Carey VK5ZEA has recently constructed his own fully operational Dstar Digital Node Adaptor (click picture to view in more detail, note there are also further pictures below to view.)
Michael's story follows.....

Last week I received my CML CMX589AP4 GMSK modem chips and quickly fitted them to my Satoshi DV Node Adapter boards which have been built ready to go for several months. With my initial experiments, I had limited success in using some Icom IC-F121S commercial radios, Satoshi had released new firmware for the DV Node Adapter that auto detected the receive audio polarity and also allowed the user to select the appropriate TX polarity as well. This eliminated the need to mod the DV Node Adapter PCB or build an external circuit to invert the audio for radios that required it. The Icom radios did work well on receive but transmit was a little more difficult to get right, it didn't seem to matter where I injected the transmit audio, things just didn't work very well.

I've not given up on using the IC-F121S radios but I found that another radio I had lying around worked even better. I ended up pressing an old Simoco SRM9010 radio into service and immediately found that it worked 100%, all the time!

One of my first contacts using the DV Node Adapter plus the D-Star Hot Spot software was Demetria, K4DPW. I was thrilled to make my first D-Star/Dplus contact using a non-Icom solution at the business end (of course, I was talking into an Icom IC-91AD, but the gateway to Dplus had no Icom gear anywhere near it!)

I've had it running on and off through the weekend and it's been connected to REF001 C most of today with no issues at all. I love home-brew D-Star gear!

Regards,
Michael.
VK5ZEA

Related Files

Close up photograph of the Icom transceivers and node adaptor.
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Close up photograph of the Dstar DV node adaptor circuit board.
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Close up photograph of the Simoco transceiver and DV node adaptor board.
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