Could one use a length of iron or copper pipe as an RF choke on coax or
speaker leads? I've seen lengths (1m) of ungrounded copper pipe on coax
used as lightning chokes.

On Apr 19, 3:04�pm, No Spam wrote:
Could one use a length of iron or copper pipe as an RF choke on coax or
speaker leads? �I've seen lengths (1m) of ungrounded copper pipe on coax
used as lightning chokes.

I don't know about iron or copper, but in the early 90's someone
suggested that a tube of steel wool could effectively replace the
ferrite beads normally used in choke baluns. That was proven to be a
bad idea. I would suspect that iron or copper pipe would be far less
effective than ferrite beads. If you check the choking impedance of
say 50 beads vs. an equal length of pipe, you will find the beads
vastly superior.

Gary N4AST

On Sat, 19 Apr 2008 14:15:50 -0700 (PDT), wrote:

On Apr 19, 3:04?pm, No Spam wrote:
Could one use a length of iron or copper pipe as an RF choke on coax or
speaker leads? ?I've seen lengths (1m) of ungrounded copper pipe on coax
used as lightning chokes.

I don't know about iron or copper, but in the early 90's someone
suggested that a tube of steel wool could effectively replace the
ferrite beads normally used in choke baluns. That was proven to be a
bad idea. I would suspect that iron or copper pipe would be far less
effective than ferrite beads. If you check the choking impedance of
say 50 beads vs. an equal length of pipe, you will find the beads
vastly superior.

Gary N4AST

I believe that in order for a pipe to be effective, it would have to
be some distinct fraction of a wavelength of the signal you want to
block. If you have problems with 80 meters, it could be a very long
pipe.

On the other hand, the ferrite beads can cover many more frequencies
in much less space.

Buck
N4PGW

--
73 for now
Buck, N4PGW

www.lumpuckeroo.com

"Small - broadband - efficient: pick any two."