[ARC5] PL-55 and PJ-068 type plugs with retaining rings inquiry

[Jay Coward]

Mike,
 Thanks for the reply and RL-7 diagram. I just looked over my RL-7 and it's jack boxes and yes they too have the headset/audio retaining feature (the jack boxes too) but not the MIC jacks.
 Now where is the motherload of these plugs? :-)
  Jay KE6PPF


-----Original Message-----
From: Mike Hanz <aaf-radio-1 at aafradio.org>
To: Jay Coward <jcoward5452 at aol.com>
Cc: ARC-5 <arc5 at mailman.qth.net>
Sent: Wed, Jul 3, 2013 6:50 pm
Subject: Re: [ARC5] PL-55 and PJ-068 type plugs with retaining rings inquiry


On 7/3/2013 8:51 PM, Jay Coward wrote:

> Ever notice on ARC-5 gear that key and mic jacks have extended threads on the 
outer sleeve? I have two plugs that fit the key jacks on several of the 
transmitter control boxes and MD-7 and can be secured with a threaded retaining 
ring.
>
>
>   One is marked B180207 and has a black plastic shell. The other is marked 275 
and appears to be able to be soldered directly to a properly prepared shielded 
cable.
>
>
> Can anyone elaborate on this? Obviously someone thought it important that 
these did not get inadvertently unplugged.

That's clearly the intent, Jay.  The RL-7 interphone manual shows eight 
of them in use, for the transmitter sidetone jack, two receivers, and 
the pilot's throttle switch.  Inexplicably, the microphone plug to the 
transmitter is not so equipped, not any of the station jack boxes.  The 
part number in the manual is NAF-C310572-1, which matches a few I have 
here for the RL-5 as well.  The NAF (Naval Air Facility) designation 
sorta implies a specialty version of something for Navy aircraft use - 
you don't see huge production numbers normally associated with them.

> So why are these uncommon?

Because there turned out to be few compelling applications for such 
cautious safeguards as time went by?  That's the only logical reason I 
can think of.  One would think that they would have received a standard 
Navy 5 digit number if the acquisition quantities became high enough, 
but there seems to be plenty of the more common NAF 215285-2 and NAF 
1136-1 plugs still around.

          73,
  - Mike  KC4TOS