m II wrote:
Michael Black wrote:
You needed
to convert radio to a lower frequency to get any sort of amplification.

Could you clarify this for me? I don't believe frequency generally has
an effect on the ability to amplify.

mike

This might have been true back in the audion days, but it would not
have been valid with octal or miniature tubes like a 6SK7 or a 6BA6.
These more modern tubes had plenty of gain at 455kcs.

After WW2, a lot of hams used a BC-453 ARC-5 receiver to make a double
conversion system out of their single-conversion shortwave radio. The
BC-453 was tuned to the 455kc IF, and its 85kc IF gave improved
selectivity.