Monday, February 9, 2015

Low-Cost Pixie Transceiver Kit

The Pixie transceiver is a simple QRP amateur radio transmitter design. I earlier blogged about and made a YouTube video covering's version of this design, the Lil Squall.

I recently picked up one of the inexpensive Pixie kits that are sold on eBay. This one was only US$6.80 with free shipping, so I thought I would take a chance and buy one.

After a few weeks waiting for shipping, it arrived. The kit includes a nice silk-screened and solder masked PCB and all parts and connectors including a 7.026 MHz crystal and a 2 Watt 47 ohm resistor for use as a dummy load.

It needs headphones, a code key or keyer, and antenna and power source. It runs on 9-12 VDC and puts out about 600mW of RF power.

It went together in less than an hour and worked when I powered it up. It uses one IC, two transistors, and fixed inductors (no toroids to wind). The parts are all through-hole. The board is a little tight with some parts mounted vertically. It came with two sheets of instructions - basically a parts lists and a schematic - which was adequate to figure out how to put it together for someone with some experience with electronics.

On transmit I measured 240 mW at 9VDC and slightly less than 600mW of RF power at 12VDC into a 50 ohm dummy load.

The transmit frequency is fixed by the crystal, but the receive frequency can be adjusted slightly using a potentiometer. You could use different crystals but the circuit is only intended for the 40 meter band with the parts supplied.

As is typical with this design, this is not an easy rig to make contacts with due to the lower power and fixed frequency. The receiver is also not very sensitive and can suffer from AM broadcast band station overloading. A preamplifier, like this Ameco unit, can help a lot.

The one I bought was listed on eBay as "HAM RADIO 40M CW Shortwave Transmitter Receiver 7.023-7.026MHz QRP Pixie Kit DIY".

All in all, a fun little kit for the price.

1 comment: said...

These Chinese pixie kits are great fun to build! If you want an even smaller QRP kit thats fully built and made in America then check out the new KeychainQRP HF transmitter. It's so tiny you can keep one on your car keys and not even notice its there! You can currently find them on Etsy.