Saturday, September 05, 2015

ozQRP MDT Double Sideband transceiver kit review

I learned of the Minimalist Double Sideband Transceiver (MDT) kit from the video review by VK3YE and thought it might be a fun project.



The price is $75 but it includes everything you need except a microphone. The parts are well packed and clearly marked. The circuit board is excellent quality and all parts fitted well.


The manual is very clear and I found construction quite smooth.


The only confusion I experienced was figuring out which way around the BD139 transistors go in the board (the label side is closest to the edge of the board).

I spent a lazy Saturday on and off doing the build in short bursts. Late in the afternoon I was tuning around and the direct conversion receiver sounds excellent. The carrier nulling was easy and from what I can hear off air transmit audio sounds good. So far no one has responded to my CQ calls for a report but I'll get back to you when that milestone is passed.

It's a great kit for a constructor with at least a little experience. A very compact rig that could be good to take on a hike.

Update: First contact with Mal, VK2BMS who said the audio sounds good although a little basey - which is probably more due to the microphone than anything. Mid dial was 7.10604 so that's good to know.

With the second varicap link open mine covers 7.090 - 7.127MHz. Tuning is quite sensitive so I wouldn't want more range without a multi-turn pot so I think this is a good range.

Just had another contact with Ian, VK3AXH in Ballarat who gave me a 5 and 3. He's running 200W and I'm running about 2W DSB. He commented that the rig is "doing a remarkable job". I do find that after switch on it drifts a bit but it's a pleasure to use.

2 comments:

Joel Caulkins said...

Peter, I built one also and thoroughly love using it. Mine is running on a 7.38Mhz ceramic resonator that puts me nicely into the US ham band. It covers from 7.213 to 7.298, so 84Khz coverage is great. I have made many contacts on mine including one at 6:00PM Tuesday night that was 420 miles away. The audio reports are good although some people say I have too much audio and others say I need to turn it up a bit, cant win there. I hope you enjoy yours as much as I do mine.

Joel
KB6QVI

ShootAnyAngle.com said...

Check out my review of the 40m MDT DSB kit from ozQRP: http://www.examiner.com/review/diy-review-mdt-ham-radio-40m-qrp-transceiver-kit