I guess this could be done in software these days. It is possible to feed left and right channels to two separate RTTY decoder instances and interpolate the decodes by eye at the level of the decoded text, but I'd have thought some cunning software ought to do a better job of comparing/combining signals using their strengths, SNR or some other quality measure, bit-by-bit. Or something.
73 Gary ZL2iFB > -----Original Message----- > From: elecraft-boun...@mailman.qth.net [mailto:elecraft- > boun...@mailman.qth.net] On Behalf Of Jack Smith > Sent: Tuesday, 19 February 2013 12:51 p.m. > To: elecraft@mailman.qth.net > Subject: Re: [Elecraft] Bridging L-R of stereo Line Out for single channel > diversity RTTY > > Classically, in ye olde days of mechanical printers, diversity combing was done > post detection in the modem. Two receivers feeding two modems, and the > detector outputs of the two modems were combined with a switching device > that selected the output with the best SNR. > > With CW, the operator's wet-ware can separate the two channels and > perform a version of best channel selection. > > Jack K8ZOA > > On 2/18/2013 6:15 PM, conw...@aracnet.com wrote: > > I'm wondering if diversity receive might help with RTTY decoding, to > > reduce deep fades. > > > > I shorted together the left and right channels from the Line Out jack > > on the back of the K3, and fed them to right input of computer sound > > card. (The left input of sound card is connected to a TS-850, for > > SO2R.) > > > > I was concerned that bridging the two audio channels in this way would > > cause the diversity separation in the headphones to be lost (e.g., > > when operating CW, and having the bridged audio line for RTTY decoding > > still connected). But the headphones seem to still work as before, > > with separate channels audible, L-R. I'm guessing there's a buffer > > amplifier that feeds the rear panel line out jack, so that shorting > > those channels doesn't effectively short the other audio L/R outputs > > (e.g., headphones). > > > > Does anyone know for sure? 'Anyone see a downside to this approach? > > > > (I recognize I might be trading one problem for another: instead of > > QSB in one channel, I now might sometimes have the L- and R-channels > > equal in amplitude and out of phase, leading to a nil combined signal > > for the decoder at odd intervals. But that seems a low probability.) > > > > Tnx, > > > > /Bill, K2PO > > > > > __________________________________________________________ > ____ > > Elecraft mailing list > > Home: http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/mmfaq.htm > > Post: mailto:Elecraft@mailman.qth.net > > > > This list hosted by: http://www.qsl.net Please help support this email > > list: http://www.qsl.net/donate.html > > > > __________________________________________________________ > ____ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
