Chicago once dispatched their cars on a frequency of about 1700 kHz. Used
to listen with a Wilcox-Gay receiver (made in Charlotte, Michigan) that had
a knob used to switch from broadcast band to the MF police band. Long time
ago!
I was of the opinion that the Chicago system was one way. Does anyone
remember?
Some of the police HF frequencies were used on CW into at least the
mid-60s. They were not allowed to use RTTY as it was thought to compete too
much with The telephone company. I visited the main HF site for Ohio in the
early 60s - the site was controlled from Columbus with a microwave link.
The engineer liked to call it the longest IF in the world.

73, Mac N8TT

--
J. Mc Laughlin; Michigan U.S.A.
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