[Collins] EV-664.

[Glen Zook]

I don't know if the connector is exactly the same as
Motorola used for decades (including the Motrac and
Motran series).  There were actually several
variations of this connector used by Motorola, General
Elecric, and several other companies.  The difference
is in the position of the alignment "slot".  The
version used by Motorola had a pin directly "in line"
with the "slot" and the version used by General
Electric had this pin offset by about 15 degrees from
the slot.  

Now 3 of the pins are equally spaced but the 4th pin,
the one nearest the slot, is slightly farther apart
from the 2 adjacent pins.

There is a retaining flat-head alignment screw that
holds the plastic insulator in alignment which goes
through the metal housing of the connector.  This is
drilled in different places depending on the
manufacturer making the radio.  If the alignment is
not correct you can remove this screw and turn the
inner assembly so that it will mate with the female
socket.  However, the plastic will be loose inside the
metal housing and you do have to be careful when
removing the plug because the pin assembly will remain
in the socket when the metal housing is removed.

Motorola and General Electric had this slightly
different arrangement on their microphones to make it
harder to use the same microphone on both brands of
equipment.  Federal Signal Corporation, the
manufacturer of emergency lights, sirens, etc.,
sometimes used the same 4-pin connector with an even
different rotation in regards to the alignment slot. 
Again, this was to "force" the end user into using
microphones sold by that company.

Again, any of the various versions of the 4-pin
connector can be used "in a pinch".  But, depending on
the actual style the retaining screw may have to be
omitted.

By the way, Johnson used another variation of this
connector for the bias switching connection on the
Thunderbolt linear amplifier.

Glen, K9STH


--- "Dr. Gerald N. Johnson"
<geraldj at storm.weather.net> wrote:

Used to be Amphenol 91-MC4M. Today its carried by
Newark and Allied under the WPI brand. It was also
used for tube vintage Motorola 2 way microphone
connectors.









Glen, K9STH

Website:  http://k9sth.com


       
____________________________________________________________________________________
Need a vacation? Get great deals
to amazing places on Yahoo! Travel.
http://travel.yahoo.com/