[TowerTalk] Orion 2800 Rotator Cable Replacement

[john at kk9a.com]

An alternative to the stretching exercise would be to purchase hard  
drawn copper wire, here are the specifications:
http://www.cmewire.com/catalog/sec02-bcc/bcc-01.pdf.  BTW, I used to  
purchase copperweld however it held so terribly at P40A that I quite  
using it.

John KK9A



Bob Shohet, KQ2M wrote

Hi Jim,

”A major advantage of using stretched wire is that un-stretched copper
will stretch under tension over years. Before changing to stretched
wire,”

I have seen you mention this a number of times in the past and I have  
been meaning to ask you some questions about it.

My non-engineering understanding of wires and stretch is that a given  
wire after being subject to variable strength forces over a given  
period of time, will stretch only so far before it breaks.  Assuming  
that that is conceptually correct, let’s say that we have two wires –  
Wire A and Wire B.  Wire A has been pre-stretched before being put up  
and is now compared against Wire B which has just been put up without  
being pre-stretched

Now we subject both wires to the same forces over the same period of  
time.  I would expect that going forward Wire A will not stretch as  
far as Wire B, but is more likely to break and break sooner under  
significant force than Wire B because it has already been  
pre-stretched.  Wouldn’t this be correct?

If this is not correct, can you please explain why?

Tnx & 73

Bob  KQ2M