[TowerTalk] FW: [EXTERNAL] FW: Topband: Source for durable ladder line?

[Tim Duffy]

I reached out to the guy that is responsible for the manufacturing of DXE
Open Wire:

 

"Below are some relevant data points for the insulation used for the Open
Wire from DX Engineering:

 

Low Temperature Brittleness Point:                        -76C

Environmental Stress Crack Resistance:                 Min. 1000 hours

 

The environmental stress crack test is a standard method which involves
placing a sample of polyethylene into an apparatus filled with 10% igepal
solution.  The specimen is exposed to specific temperatures and loads to
induce stress cracking.  These results are quite good showing this to be a
very stable insulation when exposed to extreme conditions. I would list it
as -20 degrees F.

 

Also, black color concentrate is known to be a generic UV stabilizer.
Although there is no testing data on this particular product, comparable
products have passed UL's 720 hour sunlight resistant test.  That doesn't
mean that it is only able to block UV for 720 hours, that is just the test.
I would suggest that UV resistance would be 10 years.  Temperature variation
shouldn't matter other than the fact that 10 years in the Arizona sun in
much different that 10 years in NH.  

 

I certainly don't think the cold weather alone would cause this fracturing
given this materials brittleness point.  I tend to think it would be a
combination of all the elements it is exposed to and it also may have to do
with the age of the product.

 

So being conservative we say -20 deg F and 10 year UV resistant."

 

DXE tries very hard to deliver the best possible product.  

 

73,

Tim K3LR

@ DX Engineering

 

-----Original Message-----
From: Topband [mailto:topband-bounces+k3lr=k3lr.com at contesting.com] On
Behalf Of John Kaufmann via Topband
Sent: Sunday, January 12, 2020 10:27 AM
To: 'topband'
Subject: Topband: Source for durable ladder line?

I'm looking for a source for durable ladder line for making two-wire
reversible Beverages for use at the KC1XX contest station. In the past
we've used the line sold by DX Engineering but over the years we've found
that the plastic spacers between the wires become brittle and break off. It
may be UV exposure that causes this. We also get some pretty severe weather
at KC1XX hilltop location, with ice in the winter and frequent strong winds.
The spacer breakage sometimes exposes the wires, which then become twisted,
and the ladder line generally becomes weakened and prone to wire breakage.



What else is available commercially?



73, John W1FV