Hey Bob, Thanks again for the rapid reply. As a rookie, I'm always looking to learn more!
What you've said didn't make much sense to me. Oh, you're quite clear, but the logic was confusing. Why would a radio cause a virtual PTT, tripping the microphone when the rear ACC1 port is in use? So, I fired up the spectrum scope. Sending tone only, the waveform doesn't change when speaking into the microphone. Whether using PTT or not. Regardless of mic gain and other settings. Not to be one to doubt, but I do tend to verify. 8-) So, I called Icom. Icom technical support says that an earlier version of the IC-746, in error, did that. But modifications since then have stopped that on newer versions of that model. They said the IC-735 never had that problem. So, I think I'll post this in the forum. Maybe others can offer their experiences? Vy 73, de Frank, K2NCC -------------------------------------------------------- On Thu, Jun 12, 2008 at 3:12 PM, Bob Donnell <[EMAIL PROTECTED]> wrote: Hi Frank, The comparison to operating VOX sounds like you took it too literally. The reason you want to unplug the mike is that when you ARE transmitting with any soundcard mode via the ACC connector, the mike will be LIVE - all room noise will be transmitted at the same time as your data transmission. If you have the radio's mike gain turned up pretty high for your digital setup, it'll pick up room noise even better. Any conversation you (or anyone else) might be having in the room at the same time as you're transmitting PSK31 (for example) may be able to be heard by people listening to yours or other digital stations operating near the frequency you're set up to transmit on. This is what you don't want to have happen. VOX operation had nothing to do with this, other than as an example of another way that room noise could end up getting transmitted on frequencies not legal for you to operate phone on. 73, Bob, KD7NM
