hi Tim - Never ever seen that. I'd suspect audio cabling first, and a
defective sound card second. Fortunately both are relatively easy to swap
out and see. Or perhaps your levels are so high it is bleeding over, but
then you would be getting overflow warnings and having other issues too.
Leakage between channels is not normal! 73 jeff wk6i
On Fri, Sep 4, 2015 at 9:47 AM, Tim Shoppa <tshoppa@gmail.com> wrote:
> I am a bit mystified by some observed behavior in my SO2R RTTY setup.
>
> I feed the left radio into the left audio channel, and feed the right radio
> into the right audio channel.
>
> I have one MMTTY and one 2Tone per radio, each set up to only look at the
> appropriate left or right audio channel.
>
> Doing this all in SO2R seems to work. But every so often a really loud
> signal on radio 1, will be decoded and printed in the decoder for radio 2,
> especially if the signal on radio 1 is pinning the S-meter and radio 2 is
> looking at a signal in the noise. Same things happen with 1 and 2 reverse.
>
> The first time this happened I was stumped, but then figured out that I had
> left a microphone plugged in to the sound card at same time. Audio was
> escaping from my headphone, finding its way to the microphone, and then
> being fed into both channels! (Evidently microphones are treated as mono
> devices.)
>
> But now I have the microphone unplugged, and still the leakage is still
> continuing at a lower level. I don't see any signs of decoder leakage in
> the decoders' waterfalls when just looking at band noise and regular
> signals but we all know in a contest there are some really loud signals.
> I'm trying to figure out if this "leakage" between channels is in my PC
> hardware, in the audio cabling, or in the windows driver, maybe a
> microphonic effect in the PC case, or some common coupling through ground
> or a power supply, or what. Or maybe there is some AGC function being
> applied by the sound card ADC in response to a loud signal, such that a
> loud signal on one channel shows up very weakly in the other channel. Any
> advice on tracking this down?
>
> Tim N3QE
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>
--
Jeff Stai ~ wk6i.jeff@gmail.com
Twisted Oak Winery ~ http://www.twistedoak.com/
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