Ronnie wrote:

Hi,

This is not about ham radio, but rather a general question
about the type of cable and connectors that were found
between the antenna and the AM radio in GM cars in the
60's. I'm trying to locate some technical information about
the cable and a source for the cable and connectors.

I have an old airplane autopilot system that uses tuned circuit
to sense changes in the airplane's attitude and the position of
the control servos. Distributed variable inductances and
variable capacitors combine to establish the resonant
operating frequency of the system. The components are
connected together with specific lengths of cable and the
service manual points out that the lengths are critical because
of the added capacitance of the cable and connectors.

The cable is marked as follows:

"I. T. & T. Federal Cable R.E.C."

It is a shielded cable with a spiral wound center conductor
that looks very much like the antenna cable I remember finding
in GM cars in the 60's. It also has the same type of connectors.
There is a center pin for the center conductor and a metal sleve
that extents back over the cable and makes a connection with the
shield and chassis of the radio. Friction holds the connector in
its mating socket - there are no threads, just a couple of splayed out
areas on the sleve.

I was hoping one of you might be able to point me to a source
of technical information about this cable, such as the capacitance
per unit length, etc. The one piece I have measures about 10.5 pF / foot
or 415 pF / meter, but my measurements may not be all that accurate.

Also, a source where the cable and connectors can be found today
would be appreciated.

Thanks in advance for any help.

Ronnie, N5CSE

It was RG62 93 ohm coax. The connectors were called "Motorola"
plugs.
--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida