Sunday, October 15, 2006

pixie2 modification on Kenneke Communications

Kenneke Communcations provides the memo for pixie2 modification. It describes the change of Q2 to 2N2222A to increase the output power and the addition of 0.01 uF capacity to ensure RF noise to be bypassed adequately.

It describes the AC BC Band interference to install ferrite chokes. The memo uses 5 mH. It uses 5.62V Zener Diode to be stabalize the power line to LM386. R5 to 500 Ohm and put 250 or 470 uF capacitor from pin 6 on LM386 the GND. It will get immediate improvement audio and bc interference reduction. IT recommends as follows:
  1. Definately the RF choke going to the audio input of LM386.
  2. RF Choke on headphone/spkr jack center lead.
  3. RF Choke to keyed line.
  4. RF Beads on each line to oscillator/PA resistors.
  5. Shielding between stages.
To eliminate the surging current, add 100 ohm from D1 diode cathode to key line.

1 comment:

Steve "Snort Rosin" Smith WB6TNL said...

Instead of simply cut-&-pasting, Kenneke could have at least given credit to Ed Loranger WE6W, the guy who came up with and wrote the text of those mod's. back in 1999.

http://www.indianapolis.net/QRPp-I/pixie2_WE6W-info.html