Coax cable carries electrical current? What is wrong?

[miamicuse]

I got a good quality one to four video splitter so tonight I got up to the attic and disconnected the old splitter. Nothing unusual.

Then I connect the new cable IN, then one by one I connect the cable OUT. When I get to the last one I felt a strong tinkling on my finger, you know when you rub your shoe on the carpet a few times and go touch a metal railing? Yes that feeling...I dropped the splitter. Is it static? I don't know. So I touched the splitter, which at that time has the one IN cable and three OUT cables connected, and nothing, it's OK. Then I let go of the splitter and touch the last coax cable connector - nothing...so I touched the splitter with my left hand and the remaining cable connector with my right hand, yes I feel it again. What is going on?

I then left the attic and when to the other end of that cable, which was at the time plugged into a VCR, which in turn was connected to the TV and they were running. I unplugged the connector on this end, went back to the attic and no more problem. So I hooked the last connector up.

Then I came back down and put the cable connector back to the VCR.

What caused this? Does this mean I have an electrical problem with that TV or VCR?

Thanks,

MC

[CJT]

Cable systems are notorious for carrying ground loop currents. But it could also be a leaking bypass capacitor in one of the devices to which you connected (and which could comprise a hazard). I'd probably run the incoming cable connection through a ground block and see if that changes what you see/feel.

You might find a Google search of

cable "ground loop"

interesting.

[Beachcomber]

Although Coax Cables are routinely configured to carry DC for satellite dish LNA's and LNB's, your problem sounds like a ground fault (one or more of your devices) is not grounded properly. It could be the device itself or it could be that the electrical outlet the device is plugged into has a poor or non-existent ground. If your source is Cable TV, the ground fault could be coming into your house from the cable company.

Get a voltmeter and check for potential difference between the outer conductors shield before you connect. This is more accurate than getting "shocked".

Beachcomber

[maradcliff]

VCR's are never grounded. Test that first. If it has a standard plug, reverse the plug and test again. If its polarized (one prong wider), your outlet might be reverse wired.

Mark

[m Ransley]

Use a voltmeter to find where its from. Dont use the bad unit or call the cable co if its from their end. Let us know what you find.

[Ross Mac]

I tend to agree with the above post that your problem might be a reversed neutral / hot connection. Since the VCR probably has a polarity plug just maybe your outlet has the hot and neutral switched. Carefully pop the plate and pull the outlet from the box. Take a meter and insert the probe into the large prong socket and place the other probe on the bare or green ground wire. If you see more than a couple of volts like maybe 110 or more than you need to switch the wires. Good luck, Ross

[Mark Lloyd]

In the past I have felt voltage when connecting my cable. There would be a noticeable voltage between the cable shields (you'd feel it if holding a splitter while screwing the cable on). This problem seems to have gone away since the cable company (Cox now) replaced the coax and added a ground block.

[CJT]

Better still, go to HD/Lowes and get one of the

[miamicuse]

If the problem is with the cable company end, wouldn't I have the same problem when I am connecting the splitter with the other three TV cables? I only experienced this problem when I tried to screw on the very last cable connector.

MC

[miamicuse]

What is that called? I might do that and if reversed I can reverse it.

Thanks,

MC

[CJT]

If that link doesn't work, it's described as a

"Gardner Bender

3-Wire Circuit Analyzer

Model GRT-500A Price: $4.95/ea"

[CJT]

While you're there, you might consider also getting one of these and installing it:

I couldn't find it on the HD/Lowes sites, but I'm pretty sure they have them in the stores.

[mm]

In this case, it was low voltage, but you'd better damn well get out of the habit of using two hands to test voltage. If you want to do this again use only one hand, and probably the most you'll get is a burn.

If you use two hands and it's a substantial voltage AC or DC, you're running the current right though your heart. That's one way people get killed by electicity.

if there wasn't supposed to be any voltage there and there is, there' little reason to assume it will be low voltage, since it's not supposed to be there in the first place.

You actually specifiy that you used your left and for one and your right hand for the other. You would have felt it with just one hand. Why risk your life?

Better yet, get a meter.

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

[Mark]

You are probably feeling the normal small amount of leakage current from the VCR flowing to the grounded CATV line.

If it was a small tingle and didn't knock you on your butt, its normal.

Mark

[buffalobill]

most likely you have AC voltage from your appliance trying to get thru you to the grounded side [the outside] of your cable. to eliminate worry try plugging your appliance into a portable GFI and then connect the cable. if the appliance continues to operate without tripping the GFI, half your worries are over.

[Mark Lloyd]

But don't hold unknown coax in your mouth.

[Pop]

Actually, it's not unusual to find small currents in coax. Most signal amplifiers in fact, use the coax to power the amplifier so the amp can be placed close to the antenna and the power supply at the equipment. It's also subject to fantom voltages, just as power wiring is. Try putting any light bulb (a nightlight is easy to use) across the voltage: If the voltage goes away, it's phantom power. If the voltage doesn't completely go away, then it bears looking into a little more. My bet is it'll go away completely.

: > >I got a good quality one to four video splitter so tonight I got up to the : > >attic and disconnected the old splitter. Nothing unusual. : > >

: > >Then I connect the new cable IN, then one by one I connect the cable OUT. : > >When I get to the last one I felt a strong tinkling on my finger, you know : > >when you rub your shoe on the carpet a few times and go touch a metal : > >railing? Yes that feeling...I dropped the splitter. Is it static? I don't : > >know. So I touched the splitter, which at that time has the one IN cable : > >and three OUT cables connected, and nothing, it's OK. Then I let go of the : > >splitter and touch the last coax cable connector - nothing...so I touched : > >the splitter with my left hand and the remaining cable connector with my : > >right hand, yes I feel it again. What is going on? : >

: >

: : You are probably feeling the normal small amount of leakage current : from the VCR flowing to the grounded CATV line. : : If it was a small tingle and didn't knock you on your butt, its normal. : : Mark :

[Michael Daly]

If you have a non-polarized two-prong plug on the power cable, first try reversing it. That may provide proper grounding. I've seen this kind of grounding problem with older audio equipment. I've never found out why, but know that unless all the related audio gear is plugged in with the same plug orientation, you get current leakage.

Mike

[Pop]

Good catch, Mike; I'd forgotten about that one. I'll bet that's the source.

Pop

[miamicuse]

I have a TV, a DVD player and a VHS player hooked up at that location. All the plugs have a "wide" leg and a "skinny" leg. They are all plugged into a six port surge protector which is plugged into a single outlet. The coax cable from the attic feeds into the VHS player, and another coax goes from the VHS player to the TV.

If I unplug the cable to the VHS player but plug it into the TV directly, there is no current.

I bought a $5.00 three wire circult analyzer and plugged it into the surge protector outlet and the two yellow light lit up but not the red light. So if I am reading the instructions right it means it's wired correctly.

Where should I go look next?

Thanks,

MC