running dogg wrote:

tube radios and that remains the same because of social inertia. IF for
FM is 10.7 Mhz, another standard developed early on (early in FM's
history in this case) and that stubbornly refuses to change.


And just what would you change the FM IF to? The IF frequency isn't
just plucked out of thin air. There are valid technical reasons to
select the common IF frequencies used for single conversion receivers.
Its not covered in recent engineering texts, but see if you can find a
copy of the Radiotron Designer's handbook from the early days of radio.
You will be amazed how much was known in the early days of "radio",
other than about some solid state devices.


--
Former professional electron wrangler.

Michael A. Terrell
Central Florida