Pixie 2 Build
Doug DeMaw, W1FB (SK) was one of the founding fathers of QRP building and design. He was also the guru who designed and started the Tuna Tin 2 (TT2) revolution. This lead to many new TT2 “look alikes” over the years.
One of these was the PIXIE and PIXIE 2. A half dozen of CARS members built their own PIXIE 2 at the April meeting. Hopefully sometime next fall, a slow speed 80 CW net will be born in the Jackson area using these 9 volt, shirt pocket size transceivers. Here is a short run down of the PIXIE 2 as per Jim, AL7FS and additional info can be found on his web site, http://www.al7fs.us/AL7FS2.html.
“The first under $10 transceiver that has been very successfully built and used on the air is called the “Pixie 2” transceiver. This kit has had a history over the past three to four years and has seen much experimentation and modification. The big kickoff for this rig came from Doug Hendricks, KI6DS, and QRPp magazine (The publication of the NorCal QRP Club). It was originally Published: QRPp June 1995 pp. 45-48 and was billed as “The Great Dayton Building Contest 1995” and was sponsored by the NorCal QRP Club.
This building contest was an endeavor to have fun, promote fellowship, and provide a learning atmosphere. Chuck Adams, K7QO (ex-K5FO), came up with the idea and gave Doug Hendricks, KI6DS, the job of finding a suitable project that could easily be completed in less than an hour, have readily available parts, and preferably a circuit board.
The project that Doug came up with was the Pixie 2, which is a transceiver that can be put on 40 or 80 meters, determined by the crystal frequency chosen and changing one coil. This little rig traces its origins back to where the circuit first appeared in an issue of the G-QRP Club’s “SPRAT” (The QRP Club in Great Britain). Although most of the QRP circuits today have evolved into using superhet receivers, a diversion back to direct conversion is not unusual…since QRP, after all, is a unique part of amateur radio and simplicity is certainly a part of it.
The Pixie 2 is a tiny rig, with a standard two-transistor transmitter. It’s a Colpitts oscillator, left running, and a keyed power amplifier. There is no external mixer used to feed the audio amplifier. Instead, the mixing is done at the final amplifier itself with the resulting audio taken off the emitter.
There’s no Receiver Incremental Tuning (RIT), a simple switch and capacitor in parallel, between the crystal will work as an offset though. You’ll lose QSK but, here again lies the call for enhancement. The whole idea here was to make a tiny rig that worked, with LOTS of room for improvements, using a minimum of parts.
Many contacts using a simple end fed quarter wave wire, worked against a good ground, have been made with this rig. Most of them have been over hundreds of miles away. The transmit signal is very clean as the oscillator is always running. There are no key clicks. Just listen to it!! Power output is in the 200 to 300 milliwatt range. You’ll be amazed what happens at this power level with a decent antenna.”
At the March 17th meeting, several club members participated in a group build of a RF Probe. This is the beginning of hopefully several group builds being hosted by Mike, WB8ICN to promote homebrewing interest within the club. The probe can measure RF energy from a few milliwatts up to a couple of watts. It can be used when homebrewing oscillators, filters, mixer, and driver circuits. The RF Probe will be used for the next projected which is an 80/40 meter CW transmitter called the TT2 (Tuna Tin 2, designed by Doug DeMaw, W1FB back in 1976). Mike is hoping that enough interest will be generated over the next few months to form a quarterly activity of building simple rigs, test equipment or useful shack items. If you’re interested in getting involved in this new club activity, please contact Mike at firstname.lastname@example.org or call him at 841-9401.
“The Worlds most popular SWR/RF analyzer MFJ-259B gives you a complete pictures of your antennas performance. But you can do more than just read antenna SWR and Complex Impedance. The MFJ-259B is a complete ham radio test station including — frequency counter, RF signal generator, SWR Analyzer, RF resistance and Reactance Analyzer, Coax Analyzer, Capacitance and Inductance Meter and more! We will cover the basic uses and then delve into the “advance mode” of operation to use some of the more fancy and useful features.
Heres what you can do:
– Find your antennas true resonant frequency. Trim dipoles and verticals. Adjust your Yagi, quad, loop and other antennas, change
antenna spacing and height and watch SWR, resistance and
reactance change instantly. Adjust your antenna tuner for a perfect 1:1 match without creating QRM.
– Measure your antennas 2:1 SWR bandwidth on one band, or analyze multiband performance from 1.8 to 170Mhz!
– Take the guesswork out of building and adjusting matching networks and baluns.
– Measure distance in feet to a short or open in faulty coax.
– Measure length of a roll of coax, coax loss, velocity factor, impedance.
– Measure inductance and capacitance. measure resonant frequency and approximate Q of traps, stubs, transmission lines, RF chokes, tuned circuits and baluns.