[GreenKeys] need ideas for jack field

[WA5CAB at cs.com]

There are actually two types of normalling jacks plus one that doesn't 
normal the loop.  The first type shorts the jack when nothing is plugged into it 
and inserts whatever is connected to the other end of the patch cord (or an 
external machine) into the loop when you plug its cord into the jack.  The 
military 6-channel patch panels that I am familiar with have two of these 
jacks in each loop.  They are called "Looping Jacks".  The second type has a 
machine or other device hardwired to it and when you plug a patch cord into 
it, the jack switches take the  machine out of that loop, short the loop so 
that it doesn't run open, and the machine appears on the other end of the 
patch cord.  This is called a "Set Jack".  The third type isn't in the loop and 
would usually have something like a TD, distortion analyzer, etc. wired to 
it.  This is called a "Miscellaneous Jack".

The military panels all have a loop current meter and 6-position selector 
switch, six current setting rheostats, and may have six current indicator 
lamps.  The two types most likely to be found in surplus are the TT-23(*)/SG 
and the SB-1203/UG.  I would definitely look for one of those for a while 
before trying to duplicate one from scratch.  As Roy mentioned, the jacks are 
still made but you probably wouldn't want to pay what they now cost.

Robert Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480

In a message dated 04/25/2017 16:47:11 PM Central Daylight Time, 
k1lky68 at gmail.com writes: 
> 2) At least a few of the really correct, genuine jacks that make the 
> functions possible.  Normal quarter inch phone jacks will not do.  Such jacks 
> are still made and are available (Switchcraft).   These jacks enable 
> "normalling", that is connections through for the loop with no plug inserted, and 
> connecting the plugged-in device into the loop when plug is inserted.
> 
> 
> 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/greenkeys/attachments/20170426/d3ebf9e3/attachment.html>