Talk:PSK31
Bandwidth
The image doesn't show PSK31 bandwidth. LeighKlotz
Sound Sample
There is no sound sample. LeighKlotz
AM Modulation
PSK is not produced by modulating the RF carrier directly; that would produce AM. LeighKlotz
- I believe PSK is usually FM modulated, although I think it can be AM modulated. This is true for most data radio modulation modes, even standard TV signals. Esentially, the data is modulated to an audio frequency signal, which is in turn modulated, usually with AM or FM. --ssd 15:40, 24 December 2005 (UTC)
PSK31 uses Single sideband modulation - while one could use FM or AM to send the audio generated by a PSK program, the resulting signal would NOT be a PSK31 waveform, and would NOT have the narrow bandwidth of PSK31. In effect, the computer + the SSB transmitter form a Software defined radio with the first local oscillator being the numerically-controlled oscillator in the PSK software and the first intermediate frequency being the audio signal out of the soundcard. N0YKG 19:54, 10 April 2006 (UTC)
CB
Somebody wrote: "A serious user of the Citizen's Band is an oxymoron". Well, first thanks for your comment, which really added much value to the page. I can't speak for the USA, but here in Europe we have some CBers who take their art seriously. Some who I have spoken with could probably just walk into the Advanced exam and pass it with flying colours. They just don't want to, as they prefer the friendly, inclusive atmosphere of CB to the self-righteous, cliquish, 'anal' image of ham radio that such comments project. Chris G4PDJ 08:08, 8 February 2007 (UTC)
Emission Code
Not wishing to open a can of worms, but what is the correct emission code for PSK31?. I make it 'J1B' (i.e. 'J' = SSB with suppressed - or nowadays - 'no' carrier; '1' = One channel containing digital information, and 'B' = Automatic telegraphy for machines to read). To be honest, I just write 'PSK', ' Ritty', 'CW' or 'SSB' in my log, but just wondering :-) 86.170.182.192 (talk) 01:00, 29 September 2010 (UTC)
- It would be G1B G for phase modulation. Graeme Bartlett (talk) 12:10, 29 September 2010 (UTC)
- Hmmm...That was my first thought too, but you are not phasing the carrier, you are phasing the sideband. I'll just write 'PSK', and if the man from the RA doesn't know what that means, He's in the wrong job :-)86.170.182.192 (talk) 12:54, 30 September 2010 (UTC)
- Second thoughts. I've read through Peter M's article three times now. There is one confusing reference in there about the phase shifts being like swapping the wires of a twin feeder over 31 times a second. That would be phase-shift keying, but Peter is then talking about somebody else's earlier idea, which gave him the 'genesis' of varicode. PSK31 is (as Peter says) just like high-speed morse. It is purely a transmitted 'sound'. You can cross-connect two computers' sound cards and send PSK31 back-and-to between them without any carrier (or for that matter even a radio) being involved. In fact, if my laptop's microphone 'overhears' my rig, it can even read the code through air!. The PSK 'idle' signal (i.e constant 10101010 reversals) is identical to a stream of high-speed morse 'dits' (albeit 'smoothed' with a longer rise and fall time); and 'no reversal' is a 'dah', but only twice as long and not three times longer like morse. To read PSK, the software looks at the demodulated audio waveform and compares it to how it was 180 degrees ago. If the voltages are the same then that is one state, and if they are opposite that is the other state. Really really clever, simple and elegant. Therefore I would say that the emission code is the same as for very high speed machine-readable morse, not 'on-off keyed', but sent as audio 'beeps' through the microphone. So it's 'J1B' for an SSB transmitter; 'F1B' for an FM one, etc. etc. 86.170.182.192 (talk) 18:21, 30 September 2010 (UTC)