Just thought I would pass this along. I just set up a really simple and inexpensive audio switch for SO2R applications. I found a 1 OUT/3 IN stereo audio switch at Radio Shack, catalog number 42-2112, for $14.99. This gives me headphone (or speaker) control of two audio channels for each radio, and also radio A in the left ear and radio B in the right All that's needed are a few jumpers and the above listed switch, total cost was less than 30 bucks and about 2 hours time!
The 42-2112 had 3 interlocked pushbutton switches labeled 1,2, & 3, arranged left to right. I have 2 rigs, a Mark V (A) and a 1000D (B). The left switch (1) is the Mark V, the right switch (3) is the 1000D, and the center switch (2) is both. The switch assy has 8 RCA jacks, 2 common (output) for left/right channel, and 3 switched inputs, left/right channel.
First set your headphones up on the output side of the switch, you'll need a cable made up with a female stereo 1/4" plug on one end (to accept your headphone jack) and 2 male RCA jacks on the other end to the switch. Then make up the input cables to run from the Rig's headphone jacks, each with a 1/4" male stereo plug on one end and 2 male RCA's on the other. Then open up the switch and solder 2 jumpers on the PC board, one from the the maim channel of each input pair, usually the tip of the 1/4" plug. That's it!! It works just like the Top Ten or other SO2R controllers. You can listen to Rig A, single or dual receive, Rig B, single or dual receive, or press the center switch and hear both!
I use this in tandom with a 4PDT Toggle switch to switch the Mic and PTT from A to B. This allows me to have seperate control of transmit and receive between the two rigs. I set the switches in the center of my console, above the rigs and it feels very natural...
Again, just thought I would pass it along. If anyone needs more informaion, drop me an email.. A word of caution, the grounds are all common in the RS switch so it should not be used for Mic and PTT as the Mic ground usually needs to be isolated. This does not seem to be a problem for the audio out.
73, Dave, N4XC