[TowerTalk] Coax and asphalt shingle roofs

[jimlux]

On 7/20/20 10:02 AM, Bill Ogden wrote:
> This is my month for questions. I am looking at placing a receiving loop
> (and a rotator) on my roof. The roof has architectural asphalt shingles.
> What is a reasonable way to get coax and a rotator control cable to the
> loop?  In my case, I cannot access the roof point from inside the house.
> How should I protect the cables from the rough shingles? And protect the
> shingles from being rubbed by the cables? If the answer is conduit, should
> it simply lay on the shingles or be raised somehow?
> 


I've had my coax laying on a concrete tile roof for almost 20 years now, 
and I've seen no appreciable wear. At work, we have cable laying 
everywhere on rooftops and roads and such, and they don't seem to need 
anything special.

Animals and physical abuse (people driving or walking on it) are what 
you might worry about.


You could use something like split loom around the bundle - that would 
provide some abrasion resistance. I have no idea if the stuff is UV 
resistant.


As for "getting wires from inside the house to outside the house" - Oh 
my, there are countless ways of doing that.

A couple things to think about:
1) safety - where's the lightning going to go? If you're not in a 
lightning area, maybe not such a big deal.
2) leaks - make sure that your cable goes DOWN after going outside. 
That way if rain water follows the surface of the cable back, it will 
drip outside, not inside.
3) leaks #2 - fill the hole with something so that "weather" and "bugs" 
don't come in

I'll confess that I've done an amazing number of lash up - poor 
installations over the years here in Southern California - typically 
involving a sliding window and a piece of wood to fill the gap where the 
cables aren't. What I haven't figured out is a good way to deal with the 
"screen" problem (other than cutting a hole in the screen).
And anything where a bundle of cables goes through the screen isn't 
going to be a solution where you open the window, drag the cables in, 
connect and operate - it tends to be a "window is partly open all the time".

I've also cut a fair number of holes in the walls (not in rentals - 
that's what the window, or sliding patio door, is for) - this tends to 
make co-habitants a bit more cranky than the "tear hole in screen" does.

I'm going through this now - my in-house QTH has moved from one end of 
the house to the other and is now in a 2nd story room that is partly 
over the garage.  Do I run coax along the outside of the house (along 
the eaves most likely), into the garage, up into the space above the 
garage, and then through a hole in the (fire)wall between attic space 
and room?  It would be inconspicuous, at least.  But it's a BIG project. 
  Maybe another hole in the exterior wall (see comment about XYL opinion).

I was thinking that the exterior wall hole could also be used to run 
power for Christmas lights, though, so it's not totally ham radio.