"clf" ) writes:
I seen a Sonar brand RF Linear - Model BR-21 - last evening. It had no "Band
Select" switch on it - so am wondering, what purpose it served? This one was
in ok condition - but not sure if it worked.



Do a websearch, and you'll find that it's a 25 to 40MHz amplifier.

I have no idea whether it was a legit amplifier or not, but they always
use to sell that sort of amplifier as for the business band adjacent
to the CB band. Not being in the US, I never looked at the US rules
to know if they were legit for that purpose or not.

Sonar was a big name in two-way radios.

The only reason a bandswitch is needed is if the amplifier or rig
covers more than one band. That sort of thing is common in amateur
radio, but not in other services. Note even within amateur radio,
people would build single band amplifiers (sometimes low power, sometimes
full kilowatt), and a good example of commercially built amplifiers are
all those amplfiers for the VHF and UHF bands.

Michael VE2BVW