[Motorola] Car Phones of the 1970's

[Jack]

Geoff, et al,

I join the NY Tel. Special Services group in 1970. It included the radio
gang as well as teletype and data groups (I was in both). I believe the IMTS
conversion started in the early 1970's because I remember we had a Chevy
Nomad wagon (the Bell dark olive green) that had the two-channel radio for a
long time only because the car had a lot of life left in it. The newer
vehicles had the IMTS radio/head. We have both VHF and UHF in the nY Metro
area, as well as the lowband "Highway" systyem, operating during the 70's.
There was an attempt to make the lowbad system "automatic" like IMTS; we
bought some Aerotron mobiles that were modified to work with a Secode
IMTS-like head. It was a disaster; the radio had all kinds of problems with
the motherboard contacts getting dirty. Our IMTS heads did have the 11 or 12
channel designators, depending upon the band in use, as Geoff points out.
Our problem was that the networks were always busy..we couldn't even use the
phone in our radio shop's car after awhile. Then Motorola came out with the
"channel grabber" option that camped on idle tone and rang the phone's bell
to notify the user that they could make a call. Another oddity in the NY
system was the heavy demand for "extension" handsets. There were a lot of
executive limo's that required the driver to answer the call before the
bigshot in the back seat would talk on the phone. Motorola was hesitant to
design an extension when the Pulsar came out, so NY Tel.'s engineers dabbled
with radios made by a Canadian firm called "International Syscoms", or
something like that. They had an extension model (very much like the Pulsar
head). That was a bomb, too!
I left NY Tel. in 1980 and went to the AT&T AMPS project (cellular) and the
rest, as they say, is history. I think there might still be some UHF IMTS
systems operating because I have heard idle tone on my scanner. Ma Bell
converted the channels to UHF/VHF paging and then gave them up in the late
80's as far as I know. [I never saw the Motorola head with the clear buttons
in use in the NY area.]

Jack WA2HWJ