Standard 3.5mm stereo connector wiring is: shell is ground, tip is left channel, and ring is right channel.

What kind of mic are you using?  If it is a condenser mic, make sure that the recorder is providing bias voltage on BOTH tip and ring of the mic jack.  Test it by plugging the mic into each input jack of the splitter, without the radio cable plugged in.  Also, some recorders have a "line/mic" switch to select the input level, and if set to line, will probably not supply bias voltage on the mic jack.

George, KA3HSW

----- Original Message ----

From: Bill Acito W1PA w1pa@hotmail.com To: amsat-bb@amsat.org Sent: Thu, July 28, 2011 4:55:49 PM Subject: [amsat-bb] Pin assignments on a stereo mic input?

One more for today...  I am using a stereo digital recorder for logging. It has a stereo 3.5mm mic socket. I am using a "attenuating" patch cable from the HT audio into a "stereo splitter" plugged into the mic input (it has a stereo plug, and two mono sockets ---  tip and base, and ring and base). The other side of the splitter has a mic.  So the intent it to put the HT into one channel, and the external mic (recording me) into the other channel, when recording.

I am only hearing the HT audio on playback. I have a feeling that the plug "base" connection is not ground -- it is on the ring or tip.

Any one have or know the signal assignment on a recorder mic jack?  base, ring , and tip?  I would assume it would also match the assignment of the mic input of a PC (if you know that)?

Bill W1PA