SSB and power usage

[GeneWiseman]

This is probably a stupid question but it's been on my mind for a while now. While listening to hf, does it use more power in ssb mode? I have a Tecsun pl 330 that goes through batteries pretty fast. I thought it was just because of the cell phone battery that it uses but I recently got a Eton Elite Executive that uses 4 aa batteries. It runs though batteries just about as fast. My other radios without ssb seem to be easier on batteries whether analog or digital. I am thinking that ssb is the culprit but my two examples aren't really enough for a good experiment. Am I right or do I just happen to have a couple of inefficient radios?
Thanks a lot!
Gene

 

[merlin]

Transmitting wise, SSB is about the most power eficient as there is no carrier and all the audio is in one of the sidebands.
Reception I think is mostly about the audio PA stage. for high gain and low distortion, class A or Ab amplifiers consume power even with no audio. So, battery operation, you should get the highest watt/Hr ratings for the batteries.

 

[jwt873]

An SSB signal is an AM signal. The only difference is that in order to make it intelligible, the missing carrier must be re-inserted.

This is done by mixing a signal from a beat frequency oscillator (BFO) with the incoming SSB signal at the detector. See the diagram below. (For comparison purposes, an AM only receiver diagram will have a detector rather than a product detector and there would be no BFO).

The thing is, in modern receivers, apart from the audio amplification stage, all the blocks you see in the diagram below exist on a single IC... A receiver on a chip... The extra current required by the BFO and product detector would be negligible. I can't see how receiving SSB signals could reduce battery life.

 

[GeneWiseman]

Thanks for the replies! I guess I was just wrong. I'm a little smarter now anyways. I appreciate the information!