Lostgallifreyan wrote:


I've been told that braid makes a great deal of difference to common mode
noise pickup, and that while a thin foil and loose braid is fine at UHF it's
not to be expected to do the same for HF.

Are their any good references with test numbers on this? Been googling a
bit, haven't found anything definitive yet

- 73 de Mike N3LI -

On Wed, 03 Feb 2010 11:41:18 -0500, Michael Coslo
wrote:

I've been told that braid makes a great deal of difference to common mode
noise pickup, and that while a thin foil and loose braid is fine at UHF it's
not to be expected to do the same for HF.

Are their any good references with test numbers on this? Been googling a
bit, haven't found anything definitive yet

Hi Mike,

With the CM performance being tied to foil application, such a
non-starter is bound to have only the whisp of academic research into
it if you expect to find test numbers. On the other hand, there's
sure to be a forest fire of testimonials.

To help in your search, try googling "cable transfer impedance." The
first page of responses should have a wealth of information.

73's
Richard Clark, KB7QHC

Michael Coslo wrote in
:

Lostgallifreyan wrote:


I've been told that braid makes a great deal of difference to common
mode noise pickup, and that while a thin foil and loose braid is fine
at UHF it's not to be expected to do the same for HF.

Are their any good references with test numbers on this? Been googling a
bit, haven't found anything definitive yet

- 73 de Mike N3LI -


Not that I know of, I only saw this one:
http://www.bluejeanscable.com/articles/shielding.htm
It even describes cable transfer impedance so I guess it IS useful for other
than 'telling me what I want to hear'.

I just went for braided BT2002 because I know I can reuse it. I originally
found some in a telephone exchange skip, and had used it to extend UHF TV
antenna when I had a TV, many years ago, and later for a VHF dipole. I know
that a good braid covering is good for strong AF, so it seemes highly likely
that it will work on HF just as well if it's that good on frequencies on
either end of it.