[Elecraft] Other: Can you run coax inside metal conduit?

[Mark Johnsen]

If possible run the coax perpendicular to the house wiring to keep any
coupling to a minimum.  This was my configuration in the drop ceiling of my
former house. I ran legal-limit with no issue whatsoever.  YMMV of course…

73, Mark NB1U

On Wed, Jun 12, 2024 at 1:28 PM Fred Jensen <k6dgwnv at gmail.com> wrote:

> OK. Lived for 38 years in a house started in 1925.  Knob-tube wiring.
> You can run coax in metal conduit but NOT with power wiring.  If the
> load on the coax is unbalanced, RF current will likely flow on the outer
> surface of the shield and metal conduit will probably change the SWR.
> [Because of the "skin effect" that confines alternating current to the
> outer surface of conductors, coax really has three "conductors" ...
> center, inner surface of shield, and outer surface].  I'd be surprised
> if you saw any interactions with or without conduit but it would make a
> run of multiple coax cables a lot neater.
>
> 73,
>
> Fred ["Skip"] K6DGW
> Sparks NV DM09dn
> Washoe County
>
> Jerry Moore wrote on 6/12/2024 10:05 AM:
> >
> > HIHI, the house was built in 1960 and the feeds are a huge bundle of
> > wires loosely run across the ceiling of the basement INCLUDING a
> > copper water pipe (cringe). I’m in the process of re-routing the water
> > pipe and looking for a safer way to support the wires. Just a ton of
> > work. My intent with the conduit is to keep HF/UHF/VHF around the coax
> > from getting into the electricals or vice versa.
> >
> > *From:*Fred Jensen <k6dgwnv at gmail.com>
> > *Sent:* Wednesday, June 12, 2024 12:16 PM
> > *To:* Jerry Moore <jermo at carolinaheli.com>
> > *Cc:* Elecraft at mailman.qth.net
> > *Subject:* Re: [Elecraft] Other: Can you run coax inside metal conduit?
> >
> > Yes.  You said "don't ask," but what interactions are you attempting
> > to avoid?
> >
> > 73,
> >
> > Fred ["Skip"] K6DGW
> > Sparks NV DM09dn
> > Washoe County
> >
> > Jerry Moore wrote on 6/12/2024 8:45 AM:
> >
> >     I have 30' run through my basement and want to eliminate potential
> interaction between the coax and power wires in the same area (don't ask).
> Is there any problem running coax for HF through metal coax?
> >
> >     Thanks in advance.
> >
> >     Yes, I decided to keep my K3S.
> >
> >     AE4PB
> >
> >     Jerry Moore
> >
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