Connecting 16th century antenna wire to 21st century coax

Yet another strange question from yours truly: on the roof of my house, anchored to the chimney, is a large outdoor antenna. No idea which antenna - it was installed before my time, probably 15 years ago (or more) and, for various reasons, I can't climb on the roof to find out. From that antenna and into the house runs a brown cable (or is it wire?) labeled "Belden Celluline 9275 300 ohm UHF transmission" and a bunch of patent numbers.

For some strange reason (it may have been done by the cable company when cable was first installed in the house - also before my time), that Belden cable was cleanly cut mid-way through its run across the basement. While it doesn't look like any twin-lead cable I've seen before (and, admittedly, I haven't seen that many), it has a white core which looks like frozen foam and what appear to be two very thin metal lines, one on each side of the core.

And the question: I want to find out if that antenna+cable setup still delivers a signal. I would like to do it by connecting the Belden cable to a standard RG6 coax and then to a regular or HD tuner. I understand that this connection would require a gizmo called a balun but that's as far as my understanding goes. So what type of balun is it (if there is more than one)? How difficult is it to find? I imagine I need to strip the Belden cable on one hand and the RG6 on the other in order to connect them to the balun. Is it possible and, if so, how is it done?

Thanks.

Reply to
bruno.lerer
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Typically a 300 to 75 ohm balun will have a pair of screw terminals for the twin lead connection and an F connector for the coax connection. Thus the twin lead simply needs stripping and screwing (yes, I know how it sounds) but the other side will require that you install the appropriate connector on the coax to match to the connector on the balun. Sadly the most common sort of balun to be found has a male F connector and the most common F connector for coax is also a male so you will probably have to come up with a female-female F adapter to match them up.

Reply to
John McGaw

You can pick up a 300 ohm to 75 ohm matching transformer from Radio Shack, Wal-Mart or even Walgreens for a couple of bucks. The 2 wires from your existing flat cable connect to one side and a coax cable connects to the other through a standard F connector.

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Reply to
BruceR

Here's a picture of one w/female f connector:

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From:Art snipped-for-privacy@comcast.net

Reply to
BruceR

And they had 16th century antenna wire?????????????????????????????

Reply to
LoL

TN climate may have rusted out your 300 ohm rooftop antenna, making your old system low quality or possibly useful to a radio. see hdtv antenna compass directions from entering just your zipcode at:

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Reply to
buffalobill

Yes. It was made of kite string. My friend Benjamin told me. :)

Ken

Reply to
Ken Weitzel

That old twin-lead cable reminds me of the setup in our city apartment building back in 1961. The twin-lead was connected directly to the back of the TV with screw terminals. Occasionally a wire would break and it would be necessary to re-attach it. The problem was how to strip it... The plastic dielectric was the most awful, stiff material around.

Thankfully my father showed me the way. He lit it with a match and burned away the plastic from the bare copper wires. I still remember the drip drip of hot plastic and the nasty smell it produced.

There weren't many stations, just the ABC, CBS, NBC and a struggling PBS affiliate that ran shows about "math lessons" for educational TV. There was also one big-city independent station that ran Laurel & Hardy, Abbott & Costello, the 3 stooges and some fine local children's programs.

Every few months a tube on the set would go bad. Then we called the Zenith Repairman who brought no less than 3 giant tube caddies and filled up the living room with spare replacement tubes when the cases were open. Later, every drugstore had a tube-tester available and we could test and sometimes even replace our own tubes.

Beachcomber

Reply to
Beachcomber

There you go, 300 ohms. Just like other flat lead.

This white foam might be easier to strip than the flat plastic.

You could use screws and nuts to attach this current antenna to the flat lead side of impedance matching transformer, the small white or black cylinder 1 3/4inches by a half inch, with flat lead coming out of one end, and the coax connector at the other end. (Between a dollar and 2.25. Though only surplus and hamfests charge a dollar.)

And later you could solder the leads if you wanted to.

The female coax connector on transformer will fit well with the male one on the piece of coax cable you will buy or make.

Some bigger wider ones have screw terminals for the flatlead, and if the washer has teeth, supposedly you don't even have to strip the wire. And they may have coax wire coming out with a male connector.

That's when you'll need a M-M adapter, only about 2 or 3 dollars They sell bothl M-M and F-F adaptors.

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has everything.

I haven't done it, but I think you can just connect the flat lead to the coax input of a tv, and you'll still get a picture, even if it is not the best quality. Stick one wire in the hole and touch the other lead to the threads. Still, I guess if there were no picture, I'd still try it with the matching transformer.

I used an outdoor antenna in Indianapolis in the 60's and NYC in the

70's and 80's, with flatlead. I didnt' do anything about lightening protection in either place, and never had a problem. But maybe I wouldn't do these hookups during a lightening storm. Don't know whether that caution is necessary or not.

In Brooklyn, I was up on the roof of the apartment building and found an antenna above my apartment. No one else seemed to be connected to it, and the wire ran right by my window, so I just connected myself for 10 years of ghost free viewing.

Remove NOPSAM to email me. Please let me know if you have posted also.

Reply to
mm

Thanks everyone for the info. One piece is still missing (at least for me) - how do you actually strip a clean cut twin-lead wire? Beachcomber's retelling of his father's method - burn everything around the wires - sounds good, except that if I do that in the basement (where the wire terminates and air circulation is minimal) - the resulting smell will probably be grounds for divorce and a major violation of zoning regulations :)

Nevertheless, I'm willing to use that method as a last resort. Question

- is it actually the last resort?

Reply to
bruno.lerer

Hi...

Not only smell, but lots of smoke :)

Back in the good old days (around the time sunshine was invented) I would have done it in your house by putting the lead flat on top of something hard and not important... the top of my caddy, perhaps). Then with a knife I'd cut a slit clean through it alongside each of the wires for an inch or so. Next fold back the resulting center piece and cut it off. Now you're left with what for all practical purposes is just two separate wires, easily strippable with side cutters or your knife.

I hope that's well enough explained. :)

Take care.

Ken

Reply to
Ken Weitzel

Use an Exacto knife to trim away the center insulation and then use conventional wire strippers.

Reply to
Cecil Moore

Since you have the foam filled stuff it's a little more difficult to trim away the center so I'd use a utility knife to make a slit along each side and pull the wires out. Then just cut away the remaining center carcass. Finally, attach the leads to the wire leads or screw terminals of the matching transformer.

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Reply to
BruceR

"Ken Weitzel" wrote ...

BINGO

Other than dedicated strippers (they used to make them), that is the easiest method.

Reply to
B Fuhrmann

It really pisses me off that you cant find tube testers in drug stores any longer. Whatever happened to "SERVICE". I finally had to buy my own tube tester and now I have to test them alone in my own home. The drugstore tube tester used to be a great place to pick up women, particularly those who had broken tvs. It's no wonder there is so much violence in today's society. People no longer have a place to gather and test tubes. It was always a big thrill to watch them light up, and slowly watch that meter climb into the "GOOD" (green) zone. That was so much more exciting than all these boring computer games these kids play these days.

By the way, 300 ohm tv cable will still work if it's still properly attached to the antenna and the antenna is still intact. To splice it, strip it back about an inch on each piece. Twist the two wires and bend them down along side the cable. Wrap with tape. Connect to tv and see what happens. On newer tvs you will need an adaptor. A couple bucks at Radio Shack.

Reply to
anoldfart2

Some matching transformers don't require the 300 ohm wire to be stripped at all. I don't know if they're still available, but basically, the flat cable went between two screws. The screws had a "star washer that was shaped like an inverted bowl. When the screws are tightened, the sharp part of the star washer would pierce the insulation on the cable and provide a connection to the inner wires.

-----0-------------------------------------------------------

cable

-----0-------------------------------------------------------

0=screw
Reply to
AZ Woody

I'm certain everyone is breathlessly awaiting a status report on this project, so here goes: As suggested, I bought an Xacto knife from the nearest Radio Shack; I rummaged and found somewhere a balun transformer. [As an aside, on the balun are inscribed the magic words "Sega Genesis"! If memory serves, that video game system was prevalent at the time dinosaurs still roamed the earth, although dinosaur and video game historians may quibble with the dating.]

I used the knife to strip about =BD inch of the twin lead wire and embarked on the mother of all kludges: I sort of connected the exposed twin lead wires to the input of the balun; connected an RG6 coax male-F to the female-F on the balun; connected the other male-F end of the cable to the coax input on a Radio Shack Accurian Over-the-Air HDTV ATSC tuner (now discontinued, but the best $90 I've ever spent); connected an S-video cable to the S-video out on the tuner and connected the other end to the S-video in on a Philips RF modulator (best $8 ever spent); connected yet another RG6 to the coax out on the RF modulator and the other end to the coax input on an old (about 15-20 year) RCA TV in the basement.

THEN! I turned on the ATSC tuner and the RF modulator and the TV, and set the TV on channel 3 - and every OTA HDTV station known to man (at least in my area - western Nassau County, Long Island), was there - loud and clear! (Well, not so loud - sharp-eyed readers may have noticed I didn't bother with the audio settings; this was just a test of the antenna and wire).

So thanks be given to the gods of unknown antenna manufacturers and to Belden - a 15-20 year old system is still working, with the flimsiest of setup and no amplifiers! The wonders of technology.

Reply to
bruno.lerer

Eat your heart out, Rube Goldberg. :^)

Reply to
Robert L Bass

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