On Wed, 30 Sep 2015 09:23:34 -0400, "(PeteCresswell)"
wrote:

Got two conduits going out to the garden shed: one for AC, the other for
Ethernet.

Now I want to run coax for a TV antenna out there so that I can mount
the antenna on the wall of the garden shed and route the signal back to
the house (making it basically trivial to make adjustments to the
antenna - as opposed to having to climb up on to the roof of the house).

Which conduit would you choose to share the coax with: AC or Ethernet?

FWIW, it is not out of the question to retire the Ethernet and dedicate
the conduit to the coax - because I put that conduit in before
discovering radio links like Ubiquiti's NanoStation Loco M5
(http://www.amazon.com/Ubiquiti-LOCOM...dp/B004EHSV4W),
which I now have some experience with in another application.

I'd just do that - except it involves laying out $150 for a set of those
devices.

Run the coax with the ethernet. It may be possible to put it in a
"duct" with AC "cables" but not with "conductors" in a "conduit".
I doubt interference would ever be a problem but you would have code
issues.
As for your lightning protection, you do want an electrode at the
shed/antenna and that should be bonded to the electrode at the house.
Driving 2 isolated rods is just asking for trouble.
Use a ground block on the coax at the entrance to the house and surge
protection at the TVs. It is best if this entrance is at the same
place where the power comes into the house so you can use short
conductors to the ground electrode.
In Florida it is not unusual to see "drain" wires connecting the
frames of ethernet equipment on both ends of the ethernet cable along
with ferrite beads on the ethernet cables when you are going to
another building.

You quickly find out "ground voltage" is not the same everywhere.
Ground shift in a lightning event can be very large,
You want to mitigate that with bonding.