Category Archives: Pixie

How Well Does the Pixie Receiver Work?

Posted on April 11, 2017 by robert

My club, Newport County Radio Club, just completed our third and final meeting on the 40-meter QRP Pixie kit.  We packaged the inexpensive Chinese QRP kit with sockets for the crystal and final transistor, two additional crystals (7.030 and 7.040) … Continue reading →

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Pixie with 5-pole Axial Filter Passes

Posted on March 14, 2017 by robert

Willy, W1LY, decided to try using the standard unshielded 1 uH axial inductor that the Pixie uses for it’s current 3-pole filter (C5=47o pf, L2=1 uH, C6=470 pF) as the starting point for a 5-pole filter that could easily fit … Continue reading →

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Elsie Plot of QRP-Labs 7-pole 40-m LPF

Posted on March 5, 2017 by robert

This is the schematic of the 7-pole LPF used in the QRP Labs 40-meter LPF: The plot from Elsie 2.77 for the above filter looks like this: The actual SA response curve looks like this: The curves are remarkably similar. … Continue reading →

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Pixie Perfection

Posted on March 4, 2017 by robert

As has been noted in several posts, the stock Pixie 3-pole filter is hopelessly inadequate to suppress harmonics.  A typical Pixie will have a 2nd Harmonic that is only about -21 dB down from the carrier.  An external 5-pole filter … Continue reading →

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P2N2222A for the Pixie

Posted on February 27, 2017 by robert

On Semiconductor has a variant of the old 2N2222A in a plastic case called the P2N2222A and characterizes it as a small signal RF amplifier.  I picked up a few samples and ran three of them through the Pixie.  In … Continue reading →

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7-Pole Filter + Pixie

Posted on February 26, 2017 by robert

A friend of mine, Paul K1YBE, gave me a QRP Labs 40-meter Low Pass Filter Kit.  The kit came with three T37-6 cores, some #28 wire, 4 caps, a tiny PCB, and a couple of headers. Normally used with one … Continue reading →

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A New Transistor for the Pixie

Posted on February 21, 2017 by robert

Of course the Pixie final transistor, Q2 S8050, gets darned hot, and I’ve blown one out in the past just holding the key down more than a few seconds.  With my Pixie + Red Core Filter, I was seeing about … Continue reading →

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Passing Pixie!

Posted on February 21, 2017 by robert

After experimenting with T37-6 yellow core inductors, it was time to change to the T37-2 red core.  These have a lower operating frequency, up to 10 MHz, and it is possible that they might have a higher attenuation on 14 MHz … Continue reading →

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Pixie PLUS 5-Pole LPF

Posted on February 20, 2017 by robert

My Pixie produces about 500 mW of output power when driven by a 13.8 volt supply.  The total input power to the board is about 1.5 watts.  As I’ve mentioned the Pixie only suppresses the 2nd harmonic by about 10 … Continue reading →

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A 40 Meter LPF for the Pixie

Posted on February 20, 2017 by robert

As I mentioned the 40-meter Pixie QRP rig has pretty horrible harmonics, well above the maximum allowable FCC limit (-43 dBc).  One Pixie was about -9 dBc, and the other was about -20 dBc. The output filter in the Pixie … Continue reading →

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