9046	2013-08-30 19:45:42	Peter Parker	Binaural receiver listening - experiences
Message	Date	From	Subject
Have just mocked up a simple binaural receiver. About as simple as it gets - 1 x RF preamp transistor / 2 x 2 transistor AF amp / 2 transistor VFO - all discrete parts with no audio filtering. 2 x IN4148 based product detectors (refer SP5AHT). I'm phase splitting the 7 MHz incoming signal with a trimpot + capacitor This was successful in a direct conversion phasing SSB receiver / transceiver (see SP5AHT design and my YouTube videos) and the setting for 90 degree phase shift was critical when nulling out the other sideband. Some observations: * The setting of the phasing trimpot is nowhere near critical. I suspect it's because the phase shift doesn't have to be exactly 90 degrees unlike if you needed to shift the audio later for single signal reception. As long as it's different the ears will distinguish it 'solid' as opposed to 'flat' monaural reception. * Band sounds like it has 'depth'. Sort of like stereo vs mono. It's an interesting sensation but it requires more of your brain than mono reception. Similarly mono music may be less taxing to listen to when tired. * Lightning static vs desired signal. Appear in different 'planes' so I think signals are slightly more readable in binaural mode. * CW signals on other frequencies. Interesting effect when carrier zips across band. But not as good as expected when trying to seperate signals close in frequency. * Fading. Here's the suprise. I'm sure fading was less aparent when in binaural mode listening to CW signals. A crude form of diversity reception despite the single antenna? Overall. Interesting experiment. But for a transceiver I'd either go ultra simple and straight direct conversion or have the extra audio phase shift network for a true SSB receiver with image rejection. The S/N advantage of this is higher in my view than the benefits of binaural reception. 73, Peter VK3YE
9049	2013-08-30 23:03:07	Ashhar Farhan	Re: Binaural receiver listening - experiences
Shut up and show the circuit!!! (grin) - farhan On 8/31/13, Peter Parker <parkerp@internode.on.net> wrote: > Have just mocked up a simple binaural receiver. > > About as simple as it gets - 1 x RF preamp transistor / 2 x 2 transistor AF > > amp / 2 transistor VFO - all discrete parts with no audio filtering. > > 2 x IN4148 based product detectors (refer SP5AHT). I'm phase splitting the > > 7 MHz incoming signal with a trimpot + capacitor > > This was successful in a direct conversion phasing SSB receiver / > transceiver (see SP5AHT design and my YouTube videos) and the setting for 90 > > degree phase shift was critical when nulling out the other sideband. > > Some observations: > > * The setting of the phasing trimpot is nowhere near critical. I suspect > it's because the phase shift doesn't have to be exactly 90 degrees unlike if > > you needed to shift the audio later for single signal reception. As long as > > it's different the ears will distinguish it 'solid' as opposed to 'flat' > monaural reception. > > * Band sounds like it has 'depth'. Sort of like stereo vs mono. It's an > interesting sensation but it requires more of your brain than mono > reception. Similarly mono music may be less taxing to listen to when tired. > > * Lightning static vs desired signal. Appear in different 'planes' so I > think signals are slightly more readable in binaural mode. > > * CW signals on other frequencies. Interesting effect when carrier zips > across band. But not as good as expected when trying to seperate signals > close in frequency. > > * Fading. Here's the suprise. I'm sure fading was less aparent when in > binaural mode listening to CW signals. A crude form of diversity reception > despite the single antenna? > > Overall. Interesting experiment. But for a transceiver I'd either go ultra > > simple and straight direct conversion or have the extra audio phase shift > network for a true SSB receiver with image rejection. The S/N advantage of > > this is higher in my view than the benefits of binaural reception. > > 73, Peter VK3YE > > > -- Sent from my mobile device
9051	2013-08-31 09:32:40	petervk3ye	Re: Binaural receiver listening - experiences
Farhan - it's basically SP5AHT's 80m phasing rig but without the AF phase shift network or AF low pass filter but with 2 audio amps (design for latter is comm
9052	2013-08-31 09:33:08	w8nf	Re: Binaural receiver listening - experiences
When I was messing about with phasing method SSB, I did an experiment. I simply took the monaural output of an RX and fed it through one of my SSB phase splitter circuits. The ordinary cascaded op-amp all pass design, a single quad op-amp covers 300-3000Hz adequately, using QUAD by Jim Tonne to design it. Sure enough simply splitting the phase after the demod was enough. Had a sense of 2D, although not 3D. Later I got to hear the FX
9054	2013-08-31 11:59:39	Todd F. Carney / ...	Re: Binaural receiver listening - experiences
Peter, Would you say that binaural audio increases the intelligibility or clarity of SSB? 73, Todd ------------------------------------------------------------------------------------ K7TFC / Medford, Oregon, USA / CN82ni / UTC-7 (PDT) ------------------------------------------------------------------------------------
9056	2013-09-01 04:37:41	petervk3ye	Re: Binaural receiver listening - experiences
Todd - only marginally if at all. It seems to make lightning static less harsh. It does sound different though - almost like a multipath signal on 20 metres. The real test is would you build it in a transceiver. I think I've only seen one design on the web by someone who did. It's more common to either go simpler with normal direct conversion or go more advanced with a phasing single signal receiver. Both have different performance / complexity tradeoffs and both have their place. But a binaural rx is more an interesting curiousity. 73, Peter VK3YE
9057	2013-09-01 15:43:24	Todd F. Carney / ...	Re: Binaural receiver listening - experiences

9058	2013-09-01 18:14:24	Ashhar Farhan	Re: Binaural receiver listening - experiences
Binaural experience is a little like sitting in a planetarium. There is a dark dome of noise against which signals appear in different directions and distances. It would be a perfectly acceptable transciever to have binaural receiver and a phasing transmitter. In fact, it could be ideal for those like me who ragchew rather than chase dx. It is also pretty easy to pick out weak signals. In addition to frequency of cw, now your ears can home into a direction as well. Quick! There's a weak VU4 at 10 o'clock position! - farhan On 9/2/13, Todd F. Carney / K7TFC <k7tfc@arrl.net> wrote: > >
9059	2013-09-02 01:49:26	Johan Bodin	Re: Binaural receiver listening - experiences
Yes, listening to an I/Q signal is a pleasant experience indeed. I have found "Stereo reception" quite interesting as well, it adds another spatial feeling. Just remove the splitter ahead of the mixers and connect two antennas with different radiation patterns to the mixers, for example a pair of crossed dipoles or two random wires in different directions. I got inspired by KK7B's articles on the EMRFD CD and made this selection switchable and added another switch to select either quadrature LO from a 90-degree hybrid or "same-phase" LO. I could play with this little receiver for hours on end - constantly smiling :-) 73 Johan SM6LKM Ashhar Farhan wrote: > Binaural experience is a little like sitting in a planetarium. There > is a dark dome of noise against which signals appear in different > directions and distances. > It would be a perfectly acceptable transciever to have binaural > receiver and a phasing transmitter. In fact, it could be ideal for > those like me who ragchew rather than chase dx. > It is also pretty easy to pick out weak signals. In addition to > frequency of cw, now your ears can home into a direction as well. > Quick! There's a weak VU4 at 10 o'clock position! > > - farhan
9109	2013-09-09 23:36:20	patt896	Re: Binaural receiver listening - experiences
Ref: Kanga, Bill Kelso & EMFRED/ Rick Campbell Kits?. Any news?