Did anybody else used to look for those endless loop AM
paging transmitters that operated in many larger cities during
the sixties and seventies?

	There were 4 frequencies for the whole country, 35.22,
35.58, 43.22 and 43.58 MHZ.

	They made for great propagation beacons because most of
them ran a voice loop 24 hours a day or at least much of a day.
The loop usually consisted of a station ID plus any pending
messages for subscribers to the service. Some companies like the
one in Oklahoma City on 35.58 MHZ used coded references so as to
give some degree of privacy to the customers. A typical message
might have sounded like:

	This is RadioCall paging service in Oklahoma City paging
252, Call your office. 873, Your daughter called and needs to be
picked up at the store.

	The loop would run about 30 seconds and then repeat. If
you were a subscriber to the service, you would carry a fixed
receiver and switch it on every 15 minutes or so to see if there
was anything for you. Sometimes, the tape loop would stop and
they would send tones out to activate beepers for certain
customers who did not need to listen to the tape loop. After
that, the loop would resume.

	When things were really going great guns, you could hear
a handful of heterodynes on each of those channels and it took
some concentration to dig out each of the voices to see where it
was.

	I talked briefly to the fellow in Oklahoma City who ran
that service and he told me that they started in 1955. One of
their first hand-held receivers was a long skinny thing that had
peanut tubes in it.

	He told me that the transmitter in Oklahoma City was 250
Watts. Being an AM transmitter, it was the bain of the folks who
ran public address systems in the hotels and businesses in Down
Town OKC. It was not uncommon to hear RadioCall Paging Service
as a background to whatever was supposed to be on the speakers.

	RadioCall went silent around 1980 and most of the rest
of those similar systems around the country had gone away even
before that. It was interesting while it lasted.

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