[Top] [All Lists]

[TowerTalk] CATV Hardline connectors

To: <>
Subject: [TowerTalk] CATV Hardline connectors
From: (
Date: Tue, 24 Jun 1997 08:51:00 -0400

The most elegant method is to use CATV connectors slightly modified.

I use CATV Pin connectors with "B-body", 50 ohm N connectors screwed on the
end.  This is the real deal.  This gives you the watertight O-ring seals
with no soldering except for the center pin of the N connector, which
solders easily onto the pin.  However, this method will move you out of the
"free" zone.  I'd recommend NOT using the CATV N connectors that are
available at substantially higher prices.  These are 75 ohm connectors and
the female socket is much smaller than it's 50 ohm cousin.  They are NOT
compatible and you'll break the female socket if you try and attach a 50
ohm N male to it.  Unless you are using them at UHF or higher, the
impedance bump will be unimportant, and in those cases you will probably
want to use the 1/4 wave matching stub type connector to match up with a 50
ohm termination.

My method requires real CATV Pin connectors, which will probably run you
anywhere from 7.50 each on up, unless you can find some surplus (I found
some at Dayton last year for 25 cents each for 3/4 inch line!).  The B body
N connectors will probably run you 4 or 5 bucks a piece.  Lastly you will
need a "coring tool" made for whatever size of cable you are working
with...  These run anywhere from about $25 to $45 dollars per size.  You
need these to easily and cleanly remove the dielectric from the end of the
cable, as the CATV connectors all slip inside the end and clamp onto both

If you want to save money, use this method outside and the old waterpipe
adapter type inside, where it cant get wet.

BTW, if you have a long run and 2 short pieces of cable, you can buy
splices from the same suppliers.  They arent cheap...generally about double
the price of a PIN connector, but it's very sexy, watertight, and
guaranteed impedance match.  It would be the only way to go on UHF and up.
On the lower HF freqs you can get a way with a lot of melted dielectric or
exposed center conductor without much loss.  A lot of guys will just expose
the 2 ends and strap them together the same direction,  then use a small
jumper and hose clamps to tie the centers together.  I certainly wouldnt
put this underground, but you could just cover it with a small plastic
container and tape.  Kinda kludgy, but it works...for a while.

BTW, I dont know of anyone making a .86 cable...  Times made a .84 cable in
their TX10 series.  It's real nice stuff with a much thicker shield than
most so it's hard to kink it, but the connectors are rare and therefor
pricey...probably close to double the normal ones ($15 to 25 each I'd
imagine).  I've got a bunch of 1.16 TX10 that I'll be burying soon and
those things were about $25
each for connectors and $45 for splices!  They also were not a stock took weeks to get them.

Flooded and/or armoured cables are real nice for burial.    They can be run
up the tower (I did it), but be prepared for some seepage of the flooding
compound.  It's sticky stuff!  However, it cleans up very nicely with a
citrus-based cleaner and adds some protection if your jacket gets pierced
somehow...  You'll probably have to go back every once in a while and clean
up the exposed ends at the connectors, but it's not bad.

Overall CATV cable is a great deal for hams.  You should be able to get it
for free if you haul it off...especially if you take the reel with you.
Most of the cable companies end up spending time ie. money taking apart the
reels to throw it all in a dumpster (which also costs a lot of money).  If
you volunteer to haul some of it off, you're almost guaranteed to find as
much as you want.  Initially, I would show up on site and take the reel
apart there, "throwing" the loose coil into the back of my van and leaving
the pieces of reel there, throwing what I could into the dumpster.  After I
just about crippled myself from trying to load some armoured cable that
way, I bought a landscaping trailer for that and lots of other uses.  It's
a 16 footer that'll hold 6 reels and up to 7000 lbs!  Now  I just roll it
up the tailgate and strap it in!  I've got about 30 reels of cable at my
place now...some of them with as much as 1500 feet, most of it jacketed,
and all of it at least 3/4 inch.  It's also a much safer way to handle the
cable, since it's a lot safer on the reel than off in a loose coil, and
it'll be a lot easier to uncoil it without risk of kinking, etc.

Loss wise, this stuff is almost as good as equivalent sized 50 ohm
hardline.  Losses are slightly higher due to the smaller center conductor
of 75 ohm cable, but it's minor.  I've yet to use any impedance matching
transformers.  In fact, in some situations it can actually help your

Have fun!

73, Tyler  K3MM on 06/23/97 11:46:44 PM

cc:    (bcc: Tyler G Stewart/BENN/CEC)
Subject:  Re: [TowerTalk] CATV Hardline connectors

>Fellow tower talkians,this will be my first attempt at requesting info
>from Tower Talk.I hope someone can help me.I recently aquired a
>large amount of CATV hardline.I need to adapt the hardline to standard
>PL 259 fittings.I have seen articles about this but dont recall where.Has
>anyone fabricated any or are there any manufactured that dont cost a
>bankroll.I will thank you all in advance and look forward to seeing what
>all the answers to my question might bring me.
>73 de WT9Q--Bob
Well, I have seen and read about ever scheme there is to make connectors.
like the copper plumbing method the best.  Using copper pipe fittings, one
can make about anything with a drill, a couple of bits, a file and a lot of
copper couplers.  But...

The most elligant (or maybe I should say crude) method was to just solder
and clamp pig tails to the cable and have a small amount of regular coax to
connect to the antenna or the rig.
I've also seen where guys have just bent the CATV hardline at 90 degress,
clamped them together...solder a wire across the center connectors and
placed a two liter plastic bottle over the whole she-bang.
Now all you VHFers and UHFers are going have a lot of comments about that,
but does it matter on HF?  The guys seem to get out and they really don't
use a connector at all....

Crude, but I dare say it works!  We even had to do that on the local VHF
repeater when lighting blew a hole through one of our quarter wave line
transformers.  We just soldered and clamped on some more coax.  The SWR was
1.3 to one and we ran that for three months.  Worked fine.  I don't thing
there would be a problem at HF at all.  Oh proof the hell
of it with coax-seal, tape, plastic, what have you.

FAQ on WWW:     
Administrative requests:

FAQ on WWW:     
Administrative requests:

<Prev in Thread] Current Thread [Next in Thread>