Not sure of the exact date  probably 1941 when the then new FCC re assigned broadcast frequencies. Bother band was extended from 1500 kc to 1650 kc.  In the recent past extended further. Police had a band above about 1700 kc.  Pre 1940 handbooks should have charts showing band assignments for various services including aviation.



Sent from my Galaxy


-------- Original message --------
From: [email protected]
Date: 2/25/23 3:04 PM (GMT-08:00)
To: [email protected]
Subject: [ARC5] Related Question Maybe - Re: 4-course radio ranges

Doing a little research on an ancient pilot's artifact that turned up at the museum - a cheat sheet checklist that among other preflight tasks mentions setting the radio to "tower, 1630". Other items on the list indicate it was used in a tail dragger airplane, probably radial engine & maybe open cockpit (reminds pilot to "lower goggles").

We're assuming 1630 means 1630 kc, so we were thinking we might narrow the date of the list if we find when frequencies just above today's AM broadcast band were used for air traffic control. I recall that very early police radios used that range of frequencies to talk to patrol cars. Any pilots or historians know if or when such frequencies were used for airplanes?

Thanks!
Wayne
WB4OGM