On a sunny day (11 Jun 2006 16:51:31 -0700) it happened "Telstar Electronics"
wrote in
.com:

I looked at your document. It's exactly what I'm talking about AM...
without a solid carrier at no modulation. That's exactly what mode I'm
running. With my amplifier being able to key on a multiplexed signal
from my radio... The DSB-SC mode really is impressive on the air at
high power levels. I would never go back to pure AM mode. And you
already know my feelings about SSB... it's got too many negatives for
my liking.

www.telstar-electronics.com

Hmmm does not clear up confusion, do you receive it with an AM receiver
and no BFO? Then it is no DSB-SC.

There exist AM modulation modes where the carrier is somewhat reduced during
low modulation levels..... This wil lwork, but is still AM.
Maybe that is what you mean?

You will note the 'double phase rectifier' like waveform for DBS-SC.
In case of that modified AM you have sine wave.

So: if you can receive it on an AM receiver without BFO it is AM or
a variant there of.
If you need a BFO in any way it is DSB-SC, SSB, LSB, USB whatever.

As far as range is concerned, SSB DSB will beat any system (with SSB being
better then DSB).

The variable carrier level AM, if used to give some 'extra' power to the AM
stage at high amplitudes, will give some extra rane.
however for weak passages in the audio there will be more noise then a similar
AM system with noraml carrier, as simply there will be less carrier output.

Some AM broadcast statons, if not all? Use that system.

But who knows HiFi these days.. mp3... low bitrates...