Audio Attenuator for PSK/RTTY/SSTV/...

Been using a RIGblaster plug  & play interface between the computer and the radio for digital modes. Works OK, but to get the proper output level to drive the radio, the computer volume needed to be quite low, around 10%. Since the same computer is also used to play music, I always had to adjust the volume way down for radio use, then back up to listen to music.

Finally got around to build a simple attenuator. The junk box happened to contain a 4k potentiometer with nice knob, so I used that. Computer output connects to the pot, and its wiper goes to the RIGblaster. The computer (laptop) output volume is now simply set to "100%", which is easy to reproduce, and the attenuator was once adjusted to give proper audio drive to the radio.

People with more patience should be able to put a smaller trim pot inside the RIGblaster, but I preferred to keep that as is and instead plugging the attenuator in-line.

 In the picture, the pigtail on the right side of the black box goes into the computer's headphone jack. Audio from there is then attenuated, fed via the blue/green plug into the rigblaster and on into the radio.