Robert Swinney wrote:

Respectively beg to differ, Martin. The standard telephone wire was #9
copper. It was copper, not plated with anything. There is quite a lot of it
still around. Generally the telegraph lines were heavier and sometimes they
were made of iron. I'm not sure why - extra storm protection maybe.


Robert. You must have been working with the original transcontinental
telephone lines. They were
indeed 9 or 10 gage solid copper wire. However many later Open Wire
lines were smaller gage and
copper steel.

Many farmer lines used Iron as I think it was cheaper

Bill K7NOM

The old wire chiefs had fault location down to a science. One of the first
jobs I had was working on the AT&T Long Lines test board. There were
several tests used. Wheatstone and Varley were a couple I recall. I had
the privilege of working under a retirement aged test boardman. He taught
me a lot. That was my first encounter with a Wheatstone bridge. The bridge
was part of the test board, where the test guys could patch into the various
circuits - and isolate them from traffic. Elaborate resistance records were
kept on each circuit (pair of #9 line wires). Those records were
continually updated. They made it possible for a wire chief on the test
board to locate the distance out to a line fault. This was all done away
with when the TDR (Time Domain Reflectometer) was perfected.

Crossbars, unless you are referring to the common crossbar switch in central
offices, were out on the poles and known as *cross arms*.

Little known trivia: Coast - to - coast telephone circuits existed before
electronic amplification. This were done using lumped inductance loaded,
heavy wire pairs, generally the lower capacitive, "pole pair". Expensive
enough it made most folks send telegrams.

Bob Swinney

"Martin H. Eastburn" wrote in message
...


Copper corrodes. It turns pretty green and blue. It eats up the wire.
If it is plated with something - it won't.

If you remember the old telephone lines - those with lots stretched across
crossbars....

Those are copper covered Steel. Thick - but it is known once the copper
is breached - as the steel changes the resistance. Methods were developed
to calculate the distance of the open, break or change in impedance.

We got some of this when the lines were falling down - abandoned lines.
They were on Air force property and old telegraph/telephone lines.

We used it in a massive grape arbor - strong steel copper clad wire.

Learned to coil wire with two hands that day.

Martin

Martin Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
NRA LOH & Endowment Member
NRA Second Amendment Task Force Charter Founder



Proctologically Violated©® wrote:


Very interesting!

Which then suggests brazing electrical connections?

You omitted alum, nickel, gold.

Old wiring, at least in parts of NY, were soldered AND wire nutted!!
I think soldering of splices in house wiring is a very good, safe idea.
Just not all that convenient.

Now here's sumpn fer you electricians:

I have old cloth-covered #9-10 solid wire in my old cloth-covered house,
and sed wire is, I believe, *silver plated*!!!! Well, plated w/ sumpn,
brite and shiny.
If it *is* silver, it is a marvelous idea, because sposedly the bulk of
the current density in a conducting wire lies on the surface of the wire.
If it's tin plated, the question is then *why*!
Nickel??

Might make sense then, to silver, or even copper plate aluminum wire.
Like our pennies.
--
Mr. P.V.'d
formerly Droll Troll
"spaco" wrote in message
t...



I was just looking up expansion rates of metal for another post. The next
column in the Machinery's Handbook lists electrical conductivity ratings.
I have worked with electricity in one way or another, most of my life,
but I never realized how poorly some metals that are commonly associated
with electrical connections are!

With Silver as Conductivity = 100,
Copper = 97.61 Yup.
Lead = 8.42 !!! No wonder car batteries get hot!!!
Tin =14.39 !!! Lead and tin are the main constituents of most soft
solders. If you ever needed a case for making a good mechanical joint
before soldering, there it is!

Oh-- page 2193 of the 19th edition.

Pete Stanaitis





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