On Jul 29, 5:54 pm, Anonymous wrote:
What's all this about channels 30 through 40being ssb only?

That's the gentleman's agreement in north america, yes.

I have listened for months and years here, in the U.S.,
and except for channel 38,every channel I hear, including
the upper channeels and channels 39 and 40
are all AM-only,

Your area is special. There's excpetions in parts of the country to
many of the gentleman's agreements, such as 17 being a local channel
in Oregon's Willamette Valley and the Columbia Gorge, predating the 17
North/South travel channel "rule."

If you broadcast in SSB on channels 30 through 40 here, you
wil get chewed out by someone or many someones..

Unless you're using channel 38

It seems to me that the "gentlemen's aagreement" is
to use only AM on every cb channel except for channel 38.

One of the sidebands (which one I can never remember and just flip
between the two until I hear traffic) on 38 is the de-facto sideband
calling frequency. Generally speaking, above 30 is sideband, below 30
is AM (though sometimes once in a blue moon people use FM if AM isn't
getting the job done, you don't want to run more than barefoot given
the distance, and the radios involved can run that mode).