Charlie wrote:

-ps How many times do you think Davis has tested their 9914 in the past
10+ years?

Before we go much further, is there an engineering data sheet on
Bury-Flex? I couldn't find one on the Davis RF site.

In particular, what is the rated minimum bending radius?

Coaxial cables with braid-over-foil shielding have a generic problem
that if they're bent too sharply, the foil will tear into separated
segments each about an inch long. The cable then relies on the braid for
overall shield continuity. It will still function, especially at low
frequencies, but there isn't much contact pressure to maintain the
continuity between the braid and the foil.

If a cable had been treated in this way, it's not hard to imagine that a
precision measurement at 450MHz would reveal small jumps in the loss and
SWR when the cable is flexed.

But this is NOT something you'd ever notice in a normal amateur station
operation. Even when I was using braid-over-foil coax with 1.5kW at
432MHz, and monitoring the SWR continuously, I never noticed any major
jumps when rotating the antenna. The break-up of the foil only came to
light after the cable had failed for an unrelated reason, and was slit
open for a post-mortem.



--
73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek