Thursday, February 16, 2012

Finished and boxed Ensemble RXTX SDR

I'm pleased to report that the build of the Ensemble RXTX kit is complete and I've hacked it into a box.

While there is a purpose built box available, I found something off the shelf that is the perfect width although deeper than really required.

Maybe I could fit rechargeable batteries in there?

I built to cover 20, 30 and 40m and reception is working really well. There is lots of software around but my favourite at the moment is PowerSDR IQ. Note that you need to set the audio jumpers to straight through for this software as it has no reverse I/Q setting.

So far I haven't got transmitting going, partially due to the mystery, to me, of how to control it over USB. As you can see I'm fitting a hardware transmit switch for cases where the software doesn't support TX control over USB.

If I inject a tone into the audio input socket and enable transmit in the test utility I can see that it puts out just under 1W, but for some reason the Transmit button in Rocky 3.7 is dim for me:

Update: Duh, OK, figured this out. Rocky only transmits in CW mode.

I would like to thanks WB5RVZ for the fantastic build notes. These really helped me through the process and covered great detail where it is needed.

A few of the transformers were pretty tight by the time I put the bifilar and secondary windings in them but otherwise all went pretty smoothly. I didn't solder any surface mount devices in backwards on this occasion!

My kit was short 1 10K resister - no big deal (or most likely I've put one in the wrong place...). As the construction notes say:  Even Leonardo DaVinci would have used an ohmmeter on these had he had one! Those reds and browns are really close.

Useful links

I see that KC7IGT has had a QSO, he has a video here:

So I should be able to get this going!

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