Technical Notes

A collection of articles about radios and other assorted electronics.

Automatic Volume Control Problem in PD3

A problem has been found in the automatic volume control (AVC) circuit. It occurs only on units # 17 through # 47, and affects the AVC action when in SSB mode. The fix can be left out indefinitely without causing damage. However, if you wish to experiment with the circuit, you will probably want to put it in before proceeding. January 31, 2010.

Connecting an R-388/51J Receiver with a KWM-2 Transceiver

Having a second receiver connected allows you to work “split” – that is, you can transmit on one frequency and monitor another. November 12, 2009.

Lead-Free Solder

There is a world-wide trend towards lead-free electronics. Treetop Circuits uses lead-free solder and has found there are minor differences between this and traditional solder. December 28, 2009.