Tom Donaly wrote:
The skin depth of copper at 60 hertz is supposed to be 8.53mm. That's
too thick to make a practical shield. No wonder they're having problems.

So 60 Hz magnetic fields penetrate shielded coax?
--
73, Cecil http://www.qsl.net/w5dxp

"Cecil Moore" wrote in message
om...
Tom Donaly wrote:
The skin depth of copper at 60 hertz is supposed to be 8.53mm. That's
too thick to make a practical shield. No wonder they're having problems.

So 60 Hz magnetic fields penetrate shielded coax?
--
73, Cecil http://www.qsl.net/w5dxp

Cecil, if ever I had the feeling that I was about to answer a loaded
question, this is it, but here goes anyway - "Yes, I believe a 60 Hz
magnetic field impinging on a piece of shielded coax would penetrate
the shield of that coax significantly if the shield were made of a
non-ferrous conductor."

73, Mike W4EF.............................................

Michael Tope wrote:

"Cecil Moore" wrote:
So 60 Hz magnetic fields penetrate shielded coax?

Cecil, if ever I had the feeling that I was about to answer a loaded
question, this is it, but here goes anyway - "Yes, I believe a 60 Hz
magnetic field impinging on a piece of shielded coax would penetrate
the shield of that coax significantly if the shield were made of a
non-ferrous conductor."

It's not a loaded question. I just always assumed that coax
would shield the system from 60 Hz noise and I guess I was
wrong.
--
73, Cecil http://www.qsl.net/w5dxp

"Cecil Moore" wrote in message
et...
Michael Tope wrote:

"Cecil Moore" wrote:
So 60 Hz magnetic fields penetrate shielded coax?

Cecil, if ever I had the feeling that I was about to answer a loaded
question, this is it, but here goes anyway - "Yes, I believe a 60 Hz
magnetic field impinging on a piece of shielded coax would penetrate
the shield of that coax significantly if the shield were made of a
non-ferrous conductor."

It's not a loaded question. I just always assumed that coax
would shield the system from 60 Hz noise and I guess I was
wrong.
--
73, Cecil http://www.qsl.net/w5dxp

Cecil,

Here's a link to an interesting post on TowerTalk by Jim K9YC
discussing the subject of shielding effectiveness of coax at very low
frequencies:

http://lists.contesting.com/_towerta.../msg00663.html

73, Mike, W4EF.............................................. .......

Were you interested in a field coaxial to the axis of the line, or one
that is transverse? Perhaps I could get my assistant, Beaker, to run
some tests for us. He sometimes get a little, ah, involved with his
experiments, though, so it may take some time.

Regards,
Bunsen

Cecil Moore wrote:
Michael Tope wrote:

"Cecil Moore" wrote:
So 60 Hz magnetic fields penetrate shielded coax?

Cecil, if ever I had the feeling that I was about to answer a loaded
question, this is it, but here goes anyway - "Yes, I believe a 60 Hz
magnetic field impinging on a piece of shielded coax would penetrate
the shield of that coax significantly if the shield were made of a
non-ferrous conductor."

It's not a loaded question. I just always assumed that coax
would shield the system from 60 Hz noise and I guess I was
wrong.
--
73, Cecil http://www.qsl.net/w5dxp