Armed Polite Society
Main Forums => The Roundtable => Topic started by: Hutch on August 24, 2018, 05:03:07 PM
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My house has had two different cable providers, and two different satellite receivers. There is a hot mess of stranded 75-ohm coax cable. There are no fewer than a dozen cable ends dangling in the area that the cable box(es) are tacked to the side of my house. I’m not absolutely certain that ANY of the ones I have found outside actually are terminated at the faceplate near the TV. I’m sure at least one once did. I need to connect an outdoor VHF/UHF antenna.
I have a small familiarity with how Ethernet cables are terminated, and at least some notion of the process of “toning out” cables. Is there any such method for identifying coax cables? I really don’t want to have any new cables pulled.
Thanks.
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Bridge the conductor and shield on the target cable (easiest way is just to jam a little piece of foil between them). Use your multimeter and test at the junction point until you find a cable with continuity between the conductor and shield.
Brad
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I always used a tester at work, and I think that you can get a simple one for around 15 bucks, but here's a neat trick that might work if you have a multimeter and some aluminum foil:
https://www.youtube.com/watch?v=LC76NjuU3EY
Grrr. Brad posted while I was typing.
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Get a set of alligator clip leads with it to make your connections. (True of any meter you buy.)
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Harbor Fright Tools has extended their parking lot sale through this weekend. I wouldn't be surprised if you could find that multimeter on sale for $3.99.
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Jumper wires 100 foot extension cord and a meter will find a lot of things.
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Fox and Hound type is best as it saves you from poking holes in the insulation.
https://www.amazon.com/Extech-TG20-Wire-Tracer-Generator/dp/B00APD16D2/ref=pd_lpo_vtph_328_lp_t_2
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I use a tone and trace almost daily at work on telephone cables. Never tried to use it on coax though.
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I think I've got some old coax in the shop somewhere. I'm gonna dig it up this weekend and try that aluminum foil trick from the video I linked. If I have some small enough alligator clips I'll try and short it that way too and see if there's a difference.
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Hint for the hard-of hearing: sometimes you won't hear the beep on the continuity test position, so use the ohms selection and watch the meter.
Also: Those little alligator clip leads, as well as the meter leads, have their own resistance (usually around 3-4 ohms total), so if you get that kind of reading, it doesn't mean there's a problem. Also, since the shielding has a weak connection to the screw-in part of the cable connector until it's actually screwed in to the socket, you may get an intermittent reading using the clips. In this particular case, the aluminum foil trick would make a more reliable connection. I used to use my 50 ohm dummy load on my antenna cables to avoid this problem.