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Why?

r carl

Well-Known Member
Jan 26, 2020
291
475
73
Nebraska
One day I was listening to two guys on AM, then I switched to LSB and heard them, then switched to USB and heard them there too. Is that normal?
 
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Sure is. If you turn your clarifier knob the pitch will change and you will start to hear a squeal. That is the AM carrier mixing with the carrier that the SSB receiver inserts into the RX signal on SSB to be able to demodulate the audio. This is what always pissed me off when SSB CBs were advertised as having 120 channels. They simply have 40 channels but different MODES not channels or frequencies. https://en.wikipedia.org/wiki/Single-sideband_modulation
 
One day I was listening to two guys on AM, then I switched to LSB and heard them, then switched to USB and heard them there too. Is that normal?

Sometimes. Should have to work for it with one of our little radios while mobile. (Meaning, I run into it occasionally in the big truck).

Maybe, the better all aspects of the radio rig the more likely (?).

Days of heaviest skip is when I get some “across the board”.

.
 
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So if your on USB can you hear someone on LSB?

If decent equipment is being used there can be 2 different conversations going on on the same channel if one party is using usb and the other lsb.

Say you're on ch 20 (27.205) using upper sideband. With 300 to 3000 hz audio bandwidth the signal will occupy 27.2053 to 27.208. On lsb the signal will occupy 27.2047 to 27.202.

This can't be done with typical cb equipment that's been golden screwdrivered and/or a crappy amplifier that bleeds on adjacent channels.

Play around with some web SDRs or check out some YouTube videos of Flex or Anan radios. That will give you a good visual of what's happening.
 
This is a good trick to use when you are getting interference from an adjacent frequency.

Anybody dumb enough to try blocking a group of sidebanders with a dead carrier will eventually figure out that all they have to do is turn their clarifiers and "zero beat", or put the interfering carrier on the same frequency as the sideband radio's "suppressed" carrier. They can carry on as if the carrier wasn't there at all.

73
 
Anybody dumb enough to try blocking a group of sidebanders with a dead carrier will eventually figure out that all they have to do is turn their clarifiers and "zero beat", or put the interfering carrier on the same frequency as the sideband radio's "suppressed" carrier. They can carry on as if the carrier wasn't there at all.

73

Plenty of people are that dumb. Notch filters make it really easy to ignore them. There has always been a problem with ssb operators on HF getting too close to an AM qso for various reasons. SDR receivers have a few features to deal with this, but if you have an old receiver switching to ssb works.
 
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