SSB expressed as a theoretical frequency

spacellamaman

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so re-found a radio shack 200-0629 (ats-505) bought years ago, the one with the Clarify 1.5khz knob on the side for SSB. Finally heard enough traffic on 11.175 the other day to get pretty close to the right spot and taped that sucker down.

what has occurred to me though is, if the rheostat is even and accurate (i know it's not likely) with 1.5khz on both sides, and USB for 11.175 is in the 0.25khz position, approximately, IF that is correct I would be aiming for 11.17525, in theory that is?

will the offset be generally the same regardless of freq or source tx equipment?

i have never seen it described this way, presumably for the obvious reasons of equipment design makes it irrelevant in most cases etc.

just curious if there are any thoughts on the matter or corrections.

oddball sidenote: what made me track this thing down was i was scanning thru the coverage from end to end with a BR330T recently and it actually stopped on 11.175 tx, and was remarkably understandable, though the 330 is not designed for such.
 

jonwienke

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You're overthinking this.

SSB has the carrier and one sideband removed from the modulated RF.

The receiver adds the carrier back to the RF, and used that to demodulate the audio.

If the receiver adds the wrong carrier frequency back into the RF, the demodulated audio will be off-frequency by the difference between the transmitter and receiver carrier frequencies.

The nominal frequency for the channel is always the carrier frequency, not the constantly-changing frequencies in the sideband(s).
 

popnokick

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.... and you'll also find that "tuning by ear" for what you consider to be the most intelligible, pleasant-to-listen-to audio will be the best way to tune in SSB. Minute adjustments of the "Clarify" knob will do this for you. So when you hear the "Donald Duck" initial audio sound of an SSB transmission, grab the Clarify knob and adjust to your liking... never mind whether you are "on" or "off" frequency. Also: female voices often require different adjustment than males. On a large military or commercial net such as what you are listening to, nearly all stations will be right on frequency. However, your consumer-grade radio may "drift" in frequency with temperature changes.... or just bumping the tuning knob by accident.
 

majoco

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I found a while ago that the best way to set the clarifier knob was to tune to WWV and set the dial frequency correctly, 5,000kHz or whatever, then switch to SSB and tune the clarifier for zero beat. Mark the clarifier knob with a spot of paint or nail varnish so that you can return to that setting. It may not be right for hams as they don't have to transmit on a particular frequency, especially on a net they will wander around a bit but it should be good for a known frequency.
 
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