Channel Jumper wrote:
Unless there is something special about this coax, or if you are just
going to use it for a television antenna, or something that you are only
going to receive on - THROW IT AWAY!

I will be careful how I use it, keeping in mind it's history.

once you exceed the minimum bend radius you open up the braid and the
coax is never the same again.
THROW IT AWAY!

I don't have any reason to think that the minimum bend radius was exceeded.

Coax has a shelf life - for example, Belden 9913 has a shelf life of
about 10 years. Even though it was never exposed to sunlight and it was
never taken out of the shed and was never exposed to the elements, after
about 10 years, the coax starts to degrade and break down and then it is
junk.

I had the same piece of rg-8/u running up my tower and feeding assorted
antennas -- it was there from 1986 until 2007. I never really looked it
over for any signs of wear and tear, although once in a while I would
run my analyzer through it to test the assorted antennas. If I'd
noticed anything unusual I would have taken some action, but because it
continued to serve it's purpose, I continued to use it. I'm glad I
didn't know about shelf life and all the other stuff about coax or
I might have had ulcers by now.


The kind of stuff you see at a swap meet, where the owner is still
trying to get top dollar out of it.

I knew most of the vendors at the markets and while we always
wanted to get the best from our product, I don't think anyone would
take advantage of a fellow ham.


Good Coax pays huge dividends in performance.

'huge dividends'? Maybe a little gain or less attentuation, but
certainly not enough to consider it huge.
This was free -- just passed on by a friend.

If all you are going to do is hook it up to a Ringo Ranger and put it on
a tower, above the garage door of a fire station, and the county
repeater is only 2 miles away, then yes - the quality of the coax
doesn't matter much - other then the fact that it might show a false
VSWR.

Like others has said, there is no way to predict what will happen when
you go to use it unless you attach it to a Time Domain Reflectometer and
sweep it! Something I doubt most hams would have - unless they work in
the cellular telephone industry.

No one can predict, but there is intelligent guesswork. A TDR might
tell something, but putting the coax in a live situation usually works
well enough for ham radio purposes.

I run an amateur radio station, and if everything had to meet mil-spec I
wouldn't have had much. I did have my trusty MFJ-259B SWR analyzer,
which while it is not necessarily as a TDR, did serve me well, and as
far as the coax which led to this discussion goes, it did test OK when
fed into a dummy load over the HF bands.



The criterea which I lived by over 56 years of ham radio was 'did the
signals sound good, and could I make contacts?' -- and using old
hand-me-down wires and cables, and reusing various connectors I was
totally satisfied. It was ham radio on a budget -- I would hever throw
out something I might have been able to fix up and reuse. It kept me
very happy over the years and I'm not about to change now.

My two bits worth.

Irv VE6BP

"Irv Finkleman VE6BP" wrote in message
...
Channel Jumper wrote:
Unless there is something special about this coax, or if you are just
going to use it for a television antenna, or something that you are only
going to receive on - THROW IT AWAY!

Like others has said, there is no way to predict what will happen when
you go to use it unless you attach it to a Time Domain Reflectometer and
sweep it! Something I doubt most hams would have - unless they work in
the cellular telephone industry.

No one can predict, but there is intelligent guesswork. A TDR might tell
something, but putting the coax in a live situation usually works well
enough for ham radio purposes.

I run an amateur radio station, and if everything had to meet mil-spec I
wouldn't have had much. I did have my trusty MFJ-259B SWR analyzer, which
while it is not necessarily as a TDR, did serve me well, and as far as the
coax which led to this discussion goes, it did test OK when
fed into a dummy load over the HF bands.



The criterea which I lived by over 56 years of ham radio was 'did the
signals sound good, and could I make contacts?' -- and using old
hand-me-down wires and cables, and reusing various connectors I was
totally satisfied. It was ham radio on a budget -- I would hever throw
out something I might have been able to fix up and reuse. It kept me
very happy over the years and I'm not about to change now.

My two bits worth.

Irv VE6BP


For ham use I agree, ues whatever you can get. If it is difficult to
install, then go with new stuff. I put up a tower with 4 beams stacked
above each other. Due to the difficulty in doing things over, I would not
use anything but new coax. I did mount some antennas on the side and used
some old coax as it is not difficult to replace it if it is not any good.

I have a 50 foot piece of some foam coax that is over 45 years old. It
spent about 20 to 25 years outside in use. Then just stored inside. I have
a spectrum analizer and tracking generator and swep the frequency from 1 to
1000 MHz. It seems to meet spec to about 30 MHz and then it starts to have
more loss than it should. As I get to around 400 it starts to fall off even
more.
I have not cut it open to see if the coax seems to have had water in it or
not.

A repeater I keep up started getting desense and other noise. Checked the
jumpers from cavity to cavity and found they were the problem so replaced
them. They were about 30 years old and had been in use inside a builden
that was not heated or cooled.





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