[GreenKeys] Wire

[DR HOUSE]

As usual Jim you are spot on.

All of the installations I did for Illinois Bell were with standard 24  
AWG solid copper inside wire with the four conductors insulated with  
irradiated PVC in the colors Red (Ring) Green (Tip). The second pair  
Yellow (Ring) and Black (Tip) were only used for a second loop unless  
we were "wired out of limits" in that case we would wrap the red and  
yellow conductors together and the green and black conductors together  
to lower the loop resistance.  Same with the distribution facility  
(another subject)

There were notable exceptions however.  On some dial TWX machines and  
for certain locations such as police and fire departments we would use  
what was stocked and called "SK" wire. SK wire was shielded 22 AWG and  
had just red and green insulated conductors.

Both standard inside "Quad wire" and shielded "SK wire" had what we  
called a "slow twist" which meant less than one twist per inch.  
Typically this meets Category 3 requirements.  Later, of course, came  
Category 5 and above, which is twisted to one twist per inch or greater.

Best,
Don
K9TTY
former IBT Teletype and Data I & M
Ameritech transmission engineer retired...
SMTS Excelsus Technologies, Inc. retired.



On 28 Jun 2011, at 2:25 PM, Jim Haynes wrote:

On Tue, 28 Jun 2011, Rokumon Cat wrote:
>
> I was wondering, what would be the "proper" type of wire (cable) to  
> be used for loop interconnection between teletype machines and  
> patchpanels, etc. I am currently using plain old lamp cord, but  
> would like to use something that would have been used back in the  
> day for my TTY setup.
>
Big patch panels, like switchboards, would of course use cable.

For smaller installations like on customer premises...I guess the Bell  
System would use whatever was the kind of inside wire they were using  
for
telephone installations at the time.  Which recently would be the round
jacketed station wire of 2 to 4 conductors.  Earlier their inside wire
was twisted pair or triple or quad with solid conductors and colored  
brown
or ivory.  Or multiconductor cable if they needed more than a couple of
pairs.

I've seen wire on old Western Union and Associated Press machines that
was solid conductor twisted pair with plastic insulation and a textile
weave over each wire separately.  Probably you can't get anything like
that anymore.  I've also seen it with plastic insulation alone.

Something that would be suitable would be doorbell wire.  I've seen and
used twisted pair solid conductor wire where the wires of the pair are
two different shades of brown.  I haven't been able to find that lately;
seems like recent doorbell wire is a pair one red one white.  I've also
seen twisted pair, one red and one black wire, and a gray jacket  
overall.

Now if you're talking about military installations, you would probably
find the wire run in conduit, and it might be shielded twisted pair.
Even before TEMPEST (the enemy picking up signals radiated from your
machinery and wiring) there was use of shielding to prevent radio
interference.
______________________________________________________________
GreenKeys mailing list
Home: http://mailman.qth.net/mailman/listinfo/greenkeys
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:GreenKeys at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html