Sunday 27 September 2015

Building the QRP Pixie v3 ham radio transceiver

When I saw this kit on Banggood, I just couldn't resist. A 7 MHz / 40m ham radio transceiver for just under 4€ is certainly worth a try.
The kit came with very sparse instructions, partly in Chinese. It had a circuit diagram, a parts list and enlarged PCB silkscreen with it.
I arranged the components on my desk in the order of the BOM. This made sense as it starts with the passive components.
Bits'n pieces

I was a bit unsure about the inductor values, but found a nice calculator here.
The soldering was painless and took about an hour.
The assembled 40m Pixie
For the initial tests I soldered a 9v clip to the legs of the power socket. My power supply caused a bad 50Hz hum, so I had to go for battery power.
The Pixie prefers battery power
To check the output, I connected a 50 Ohms resistor (came with the kit) to the output and had a look at it with my scope.

Transmitter output
By the looks of it, I can't expect perfect spectral purity. But it is QRP, so I can let it get away with it. The signal will most likely pass an ATU anyway.

My friend CP had printed me this case from thingiverse. A perfect fit:

The enclosure designed by egil
Next thing was listening in: With a random length of wire (abt. 3m) I could hear some stations from all over Europe very faintly but good'nuff to follow the CW QSOs. I heard all of them at the same time. There is no narrow band filter. So be prepared to use your ears/brain to do the signal processing.
There is also no volume control and the "RIT" is not accessible with this enclosure. (This THING addresses the RIT issue).
The Pixie circuit is as basic as it can get, while the nice key/phone/power/antenna sockets feel like luxury to me.

73 de dl9set

PS: You must be a licensed radio ham of the appropriate license class to operate this transceiver.

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