spamhog wrote:
PROBLEM

I have to hang a straight ~120 foot = 40 meter drop of RG-6 type
foamed dielectric coax. No way to secure it mid-way as it's an
abandoned and unaccessible chimney flue line.

Right now all the weight is on a rounded rest on top, diameter ~ 4"/10
cm, made by sticking 3 rubber pipes of different size one inside the
other and taping the coax to itself, leaning on a section of plastic
pipe

The weight is quite ~ 5 kg if I remember correctly. I think there is
no way that leaning over a 10 cm. dia. rest won't crush the foam
dielectric over the years. I may be wrong, but finding out is not
simple at all.

This thing now only carries HF and a bit of crushing is not important
(+ I can't easily test it!), but I want to make sure I can do 2 GHz in
the future, and I don't know the proper or standard way of hanging a
LONG vertical coax drop.

Now I have a chance to re-hang the coax, and I want to run it along a
load-bearing PVC-covered steel cable, perhaps 4 mm dia.. The coax
itself is the usual 6 mm -something. I am considering a couple of
options:


Maybe you have the coax and steel cable for free, but ...

why not use the coax used for cable tv service drops which has the coax
and steel cable integrated into one assembly? It's got the jacket
integrated with the supporting cable, so the loads are very evenly
distributed, etc.

Thank you K1TTT and Jim.

I am not going to swap the whole line for a self-supporting type with
steel wire in it. I have plenty of spare coax at the low end to cut
out the potentially crushed bit and just shift it up.

K1TTT: yes, you correctly point out that the goal is to avoid undue
stress, and the last several yards can be left hanging.
Iterating back, the simplest trick of all will be to
- pull it up much of the way
- tape it to the steel rope in at least 3-4 points by taping them
together for at least a couple of feet
- let the span between two tiepoints hang somewhat loose.

Thanks again!