A ham recently reported that his Flex, in transmit, sounded great in AM mode, but had distortion when he operated in SSB. When I heard this, I scratched my head and wondered how it could be possible? But...I ran an experiment, and I found it to be true.
My test was made using a second SDR-1000 in LSB mode as the receiver to copy my 5000's tramsit audio (when the 5000 was in AM mode, I listened to the lower sideband of the AM signal on my 1000 using LSB mode).
[I also performed the test with the 5K only in AM mode by varying the amount of carrier insertion (this is possible in the 5K setup menu). At 0 percent carrier insertion (i.e. DSB) the distortion is clearly audible, and it decreases as carrier insertion is increased. Again, the receiver I used for monitoring my audio was an SDR-1K in LSB mode.]
As to the reason why...I can't explain it myself, by somewhere there's sure to be some sort of mathematical analysis or intuitive explanation. I just don't know what or where they are.
By the way, if you'd like to hear the LSB vs. AM test, I can send you an mp3 file. Send an email to me at jca1955 "at" sbcglobal.net and request the "Flex AM vs LSB test. " The distortion in SSB is subtle, but you should be able to hear a difference between AM and SSB.