Is there any advantage or disadvantage to running my antenna cables
(mostly RG-8 and some RG-58 and Twinax for loops) in metallic
electrical conduit, probably 1/2" EMT?

The shack is in the basement and various antennas come in through the
roof/attic, three stories up. Currently the antenna cables drop down a
fairly clear hole shared with some vent pipes and Ethernet (CAT-5) and
phone wires.

I have some 1/2" EMT with the tools and some experience
bending/installing it.

I do observe some RFI between computers etc. throughout the house and
the ham/SW antennas. Would putting either the coax or the CAT-5 or both
(separate conduit) help any?

I'm guessing the antenna and ethernet conduits, if I do it, should be
bonded to the household ground near the electrical panel etc. for
safety. Am I likely to get any grief from the electrical inspectors by
using metallic conduit for running non-AC cables, or for bonding it to
the same grounds? To me it's a no-brainer that a common ground would
increase safety but in past electrical inspections they've given me
some minor grief for the antenna cables which were well-grounded near
the entrance panel. They pointed to a really really crappy CATV
installation and said that I had to do it that way.

Tim.

wrote in message
oups.com...
Is there any advantage or disadvantage to running my antenna cables
(mostly RG-8 and some RG-58 and Twinax for loops) in metallic
electrical conduit, probably 1/2" EMT?

The shack is in the basement and various antennas come in through the
roof/attic, three stories up. Currently the antenna cables drop down a
fairly clear hole shared with some vent pipes and Ethernet (CAT-5) and
phone wires.


There are no RF disadvantages of running the coax in a metallic conduit.
YOu may get some shielding and also some lightning protection if the conduit
is grounded, but it is doubtful it would really be noticed if good quality
cable is used. YOu just can not run unshielded twin lead or ballanced line
in the conduit.

wrote:
Shielded cables in conduit is fine and works. Hwoever 1/2" EMT is
just the right size for one run of RG8 or 213 (.400 cable). If your
serious about EMT use someting larger say 3" or 4" and use
the prefab bends (radius turns) so pushing cables later is not too
painful.

Wow Allison, 3" or 4" conduit is pretty heavy duty stuff, although I do
appreciate the thought of "run the conduit once and then just snake
more cables through as you need them".

I was thinking of 1/2" EMT and running individual conduits for
ethernet/CAT5 and each antenna, with the end of each conduit coming out
in an appropriate part of the shack.

Another reason for doing multiple smaller runs of the EMT is that there
is 2nd-story room where the cables run through tacked onto the wall,
it'd be nicer to have whatever conduit goes through that room to be as
unobtrusive as possible. I was thinking of multiple 1/2" EMT's up
against the wall, although maybe a single fat conduit might be less
obtrusive.

3" EMT seems to be about ten times more expensive than 1/2" EMT.
Although it undoubtedly could carry more than ten times as much RG-8
:-).

Tim.

Another reason for doing multiple smaller runs of the EMT is that there
is 2nd-story room where the cables run through tacked onto the wall,
it'd be nicer to have whatever conduit goes through that room to be as
unobtrusive as possible. I was thinking of multiple 1/2" EMT's up
against the wall, although maybe a single fat conduit might be less
obtrusive.

3" EMT seems to be about ten times more expensive than 1/2" EMT.
Although it undoubtedly could carry more than ten times as much RG-8
:-).

Instead of EMT you may want to use some of the plastic electrical conduit.
Not sure if it would meet the building codes for what you want by going from
one floor to the next. It is sort of a grey colored PVC type of pipe.
Probalby not really PVC but another plastic.
It will do nothing for the shielding, just may be neater to run than the
plain coax.