Brett: My apologies if this has already been asked and answered, but where do you have your IF offset? It should be 9000 Hz for AM operation.
Setup/General/Hardware Config/ [Check Expert] IF(Hz) should be 9000 On Sun, Dec 18, 2011 at 1:56 PM, Brett Gazdzinski < brett.gazdzin...@verizon.net> wrote: > The selectable sideband detection with sync detector is out there, the > sdr-iq has it, as well as a better > overall sync detector I think. > Its handy to click the sync button and switch between sidebands or both. > > I think the dsb also works like you think, without the carrier. > its been a while since I had one, but listening to am in the dsb mode had > it sound like AM.... > > Brett > > > > ----- Original Message ----- From: <ke...@3950.net> > To: <flexradio@flex-radio.biz> > Sent: Sunday, December 18, 2011 1:09 PM > > Subject: Re: [Flexradio] FlexRadio Digest, Vol 80, Issue 17 > > > On 12/18/2011 12:33 PM, Bob McGwier wrote: >> >>> Absolutely NOTHING. That is the REASON for having the (synchronous AM) >>> SAM >>> detector. Maybe we should not have included the AM detector at all >>> >> [...] >> >> >> I am glad it is included. Some AM QSOs, especially those involving >> antique gear, have participants separated by many hundreds of Hz, and it's >> nice in such cases not to hear the 'swoop' of the regenerated carrier >> locking in when the stations are breaking back and forth quickly. When >> everyone's very close to zero beat, of course, SAM is much to be preferred. >> >> Let me thank you right now for all the great work you have done with the >> Flex hardware and software. As I said in another venue recently "...doing >> all the filtering and demodulation with perfect mathematical accuracy in >> software not only gives you tremendous dynamic range and filtering >> capability, but it makes the recovered audio almost supernaturally >> clean-sounding. Listening to a Flex into a good sound system for the first >> time is like discovering that pillows had been strapped to your speakers, >> and gravel had been stuck to your voice coil, for all these years -- and >> finally removing them." >> >> I wonder if Flex, or anyone with the ability to do the coding, ever >> considered these four enhancements that definitely interest me: >> >> 1. Costas loop detection for receiving pure DSB with suppressed carrier. >> No transmitted carrier is required for a Costas loop sync detector. It >> depends on the audio null in the Q channel for phase lock. It makes DSBSC >> practical and supposedly does better than a carrier lock sync detector when >> propagation is turbulent, even on AM. >> >> 2. Provision for transmission and phase-locked reception of SSB with a >> pilot carrier down 20 dB or so. This was used by TMC for HF SSB broadcast >> relay gear and gave SSB a clarity, with perfectly aligned harmonics, that >> current ESSB techniques cannot (though they can come close with rubidium or >> GPS frequency standards). >> >> 3. Use of "selectable sideband sync detection" using the phasing >> technique to cancel the interference in either the upper or lower sideband >> of an AM signal. (Since there is no significant desired audio in the Q >> channel, the desired audio is _not_ cancelled from either sideband.) This >> gives a 6 dB s/n advantage over the "drag the filter edge" technique of >> chopping off one sideband when it is interfered with. This would also lend >> itself to a fantastically effective kind of binaural reception on AM: LSB >> interference in the left headphone channel; USB interference in the right >> channel; desired AM audio -- and _nothing but_ desired AM audio -- in the >> center. I have experienced this and it allows the brain to process the >> signal in a way that allows _much_ better intelligibility. >> >> 4. Adding the ability to see the modulated RF (really IF) on the receiver >> scope, instead of just the demodulated audio. This tells you a lot about >> the received signal, especially on AM, and would be a very valuable tool. >> >> >> With best Yule wishes, >> >> >> Kevin, WB4AIO. >> >> ______________________________**_________________ >> FlexRadio Systems Mailing List >> FlexRadio@flex-radio.biz >> http://mail.flex-radio.biz/**mailman/listinfo/flexradio_**flex-radio.biz<http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz> >> Archives: >> http://www.mail-archive.com/**flexradio%40flex-radio.biz/<http://www.mail-archive.com/flexradio%40flex-radio.biz/> >> Knowledge Base: http://kc.flexradio.com/ Homepage: >> http://www.flexradio.com/ >> > > > ______________________________**_________________ > FlexRadio Systems Mailing List > FlexRadio@flex-radio.biz > http://mail.flex-radio.biz/**mailman/listinfo/flexradio_**flex-radio.biz<http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz> > Archives: > http://www.mail-archive.com/**flexradio%40flex-radio.biz/<http://www.mail-archive.com/flexradio%40flex-radio.biz/> > Knowledge Base: http://kc.flexradio.com/ Homepage: > http://www.flexradio.com/ > _______________________________________________ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flexradio.com/ Homepage: http://www.flexradio.com/
