[Paul Philco322]

Listening to a Zenith from about 1950, band switch sez AM, then FM100. So why say FM 100, I have no other sets that have that mark. Ideas? Paul

[rfeenstra]

I'm listening to a Zenith 7H820.  This one has both the old FM band and the "new" one.  The old one is labeled FM 42, the new is labeled FM 100.  Perhaps yours is a carry over from older radios and people who remembered the old band.

[morzh]

Maybe when the FM band went up in frequency and crossed 100MHz, they referred to it as FM100 to distinguish between the old and the new ones?

[Paul Philco322]

I am not that old that I remember old band. Paul

[morzh]

Zenith made several models in 1940s, my Spinet being one of those, with the old FM.
Dials were marked in numbers, not MHz.
I guess, once they migrated to the modern one, they tried to avoid confusion.

[Paul Philco322]

These little Armstrong FM sets sound pretty good regardless. Paul

[Chas]

I'm probably wrong:

"FM-42" designation is the first FM band beginning at 42Mhz, the band being obsolete many years. Incidentally some receivers were marked as "channels"...

"FM-100" is the current band, containing 100mhz. So, in simple terms the names are not identically representative of what they are.

Chas

[EdHolland]

Our 1947 Zenith Console has both FM bands. IIRC the bandswitch indicator designates these FM 45 (may be 42) and FM 100. It reflects the frequency range for each, as pointed out before. The tuning dial on that radio is marked in frequency units for each band.

This also reflects the changes in radio that were happening at the time, and the battle for control of the commercial airwaves taking place between some of the technology's most notable figures.

[Paul Philco322]

Thanks for all the feedback....no pun. Paul