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[TowerTalk] CATV Hardline connectors

To: <>
Subject: [TowerTalk] CATV Hardline connectors
From: (Bob Wruble)
Date: Tue, 24 Jun 1997 07:26:07 -0700
i bot/used commercial 75 ohm tv hdline conn's and found that they
are not uoto the job....although they look good they are not designed
to handle power......better/cheaper  solution are the home brew jobs made
using brass fittings for 1/2" copper tubing.....

> From:
> To:;;
> Subject: Re: [TowerTalk] CATV Hardline connectors
To: <>
> Date: Tuesday, June 24, 1997 5:51 AM
> 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
> conductors.
> 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
> matching.
> Have fun!
> 73, Tyler  K3MM
> on 06/23/97 11:46:44 PM
> To:
> 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.
> I
> 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
> out
> of it with coax-seal, tape, plastic, what have you.
> Lee
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