Competitive Cables 

Custom Cabling Solutions for Competitive Radio Amateurs

by Robert E. Naumann N5NJ

SO2R-1 Two Radio Switching System

Interfaces with most popular contest logging (CT, NA, TR, WriteLog) programs to switch your headphones, microphone, footswitch, and keyer between two radios to support "Single Op, Two Radio"(SO2R) operation.  Also included is the ability to key your modern (positive keying) radios for CW transmission from a single LPT port on your computer.

Consists of two cabinets, one small unit that is to be located adjacent to your keyboard, and the other larger unit which should be located near the back of your two radios.  A flexible multi-conductor cable connects the two cabinets.

On the small unit are 3 switches:

One low pressure, momentary pushbutton switch that swaps your headphones to the "other" radio.
A toggle switch that enables "stereo" listening - both radios, one radio to each ear
A toggle switch that manually switches between your two radios when not contesting

On the large unit are:

Individual Phono (RCA) jacks for each radio for CW keying, receive audio, PTT
6' Cables with a 1/8" plug to connect to a standard  mic adapter on your radio mic socket 
6' Cable to accept a standard 1/8" mic plug from your headset mic or other
6' Cable with a 1/4" stereo jack for your headphones
Cable to connect your computers's LPT port
Stereo Jack to accept the output of your CW keyer & paddle
Connection to your 12 volt DC supply

The schematic is included here:


Custom made by N5NJ in Plano, TX.

One year  warranty.

This item is special order only.  Please contact N5NJ for details of pricing and delivery.

Please email any questions to [email protected]

Robert E. Naumann

3568 Teakwood Lane

Plano, TX 75075-1752



Try AOL FREE! 250 Hours