Wes Stewart wrote:
I agree with Ian's comments, the larger sizes
[of hardline]
are often available here
as they are less attractive to hams. But if you buy 3 or 4 lengths of
LDF5 or LDF6 and use connectors to join them, you will run into big $
unless the connectors come very cheap.

Generally the same applies to the connectors as to the cable itself -
the surplus prices are much lower than the new prices, and larger sizes
may even be cheaper.

However, I do agree that you don't need connectors in order to make a
splice in a static installation. This technique makes a solid splice,
with a low SWR even at 432MHz:

I have a ham friend who uses long runs of coax to his several towers.
He is a big gun on 80 and 160 meters, so this mainly applies at m-f to
h-f. He uses a lot of LDF5-50 that he obtains in shorter pieces.

His technique, as he briefly described it to me, is to -not- use
connectors but splice the lengths directly. The center conductor on
these cables is hollow, so he inserts a short length of brass or copper
into the ID and solders it in place.

And for the smaller sizes with a solid center conductor, splice with a
short length of hobby brass tuning over the outside.

I don't know whether he adds any insulation next or not, but I would
envision injecting some low-expansion spray foam later.

The foam is mostly empty space anyway, so even at UHF an inch or so will
hardly be missed.

He then wraps the outer conductor with brass or copper foil and solders
this in place.

In some sizes, a slit length of copper water pipe can work too.

This is then wrapped with tape for protection. I would use a double
layer of #27 3M tape with an overwrap of plastic electrical tape.

To strengthen the joint mechanically, he straps on a length of steel
angle using stainless hose clamps.

Yup, all of the above. It works fine.

The overall conclusion is that - both physically and financially - large
hardline is nowhere near as 'hard' as most people think.


BTW, I do have one genuine Andrew splice for LDF5-50, which I'm hoarding
for some undefined future need. It's truly a thing of wonder...
especially the insert that connects the two hollow center conductors.
One end screws in with a tapered variable-pitch thread, so the other end
has to have a tapered variable-pitch *left-hand* thread. Only a CNC
programmer with far too much time on his hands could have thought of
that.



--
73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek