[TowerTalk] Matched "Bury Flex" cables

[Dino Darling]

Actually, its well known that the velocity factor in a single run of coax 
can vary.  You won't have this problem with Andrew Heliax 
(essentially).  Whenever you use coax for phased lines, you need to check 
them for proper electrical length; rough measurements don't always 
work.  Cut long and trim as necessary.

At 11:27 PM 07/13/2005 -0400, you wrote:
>I recently purchased a 1000 ft roll of Davis BuryFlex cable, planning
>on using it to replace old RG-213 cables on my 15M and 20M 3-stacks.  I
>pruned one length of cable for an odd multiple of quarter waves at
>21150 kHz and then proceeded to cut two others to the exact length of
>the first cable.  Much to my surprise, when I checked the electrical
>length of the other two cables, I found them resonant well below the
>15M band.  I had to remove 4-5 feet of cable from each run (approx
>142ft) to get them to resonate.  Has anyone run into a similar
>experience, where the apparent velocity factor of the cable varied in a
>single run?  I haven't checked the 20M lines, which I made in a similar
>fashion, but hope to be lucky with them.
>
>Sig
>
>_______________________________________________
>
>See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless 
>Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with 
>any questions and ask for Sherman, W2FLA.
>
>_______________________________________________
>TowerTalk mailing list
>TowerTalk at contesting.com
>http://lists.contesting.com/mailman/listinfo/towertalk

Dino...k6rix at earthlink.net