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Joined: Mar 2004
Posts: 32
C
Member
Kinda along the lines of my last post, can RG-6 be cut with wire cutters live? I would think not given that even 3 volts (an assumption, maybe much higher) across a few mOhms would create a high current condition; however, I realize that at high frequency, the cable impedance can appear a lot higher (75 ohms to be exact), which does beg the question, can a guy get away with dead shorting a 100' (or much longer really) cable?

Joined: Dec 2003
Posts: 886
H
Member
Unless the cable is carrying power for something like a downstream line powered amplifier or an LNB on a sat dish there should be nothing but micro volts of RF.

Even if carrying power the power supply is almost always short circuit protected. If you suspect line powering though be nice and disconnect it before you cut, but you probably won't cause a problem if you don't. There is certainly no problem with unpowered cable.

The only case that I could think of that could cause a problem is with the cable supplying an on premises extender amplifier that is line powered by the outside CATV plant. 60 volts AC and there are fuses out there someplace. This usually isn't done very often though.

-Hal

Joined: Apr 2002
Posts: 914
E
Member
Speaking from experience, if the RG6 is connected to a powered multiswitch for a satelite, don't cut it live!!!

Joined: Aug 2001
Posts: 7,520
P
Member
Yes, it depends very much on what is being fed down the cable.

If it's plain RF signals, then it depends upon the power level. I wouldn't want to cut coax live out of a transmitter as it may well damage the final amp stage.

As for cables with superimposed DC power, I know somebody who got so fed up with a cable-TV company that kept billing and wouldn't disconnect the service that he decided to disconnect it himself. It took out the CATV power to whole block!

Joined: Jul 2004
Posts: 625
S
Member
So, Trumpy, did they disconnect him then? [Linked Image]


(Edited to add: I thought I recognized the accent, but I was just a little, teeny bit off--I meant Paul.)

[This message has been edited by SolarPowered (edited 10-18-2004).]

Joined: Oct 2003
Posts: 156
D
Member
No problem cutting coax live or not. What is important, at least in my industry, is to use special coax cutters as not to deform the coax.

Joined: Aug 2001
Posts: 7,520
P
Member
Quote
So, Trumpy, did they disconnect him then?
Trumpy? [Linked Image] I know we're both those Commonwealth guys with the funny accents [Linked Image], but I reckon that was aimed at me.....

Yes, they finally got the message!

Joined: Jan 2003
Posts: 1,429
L
LK Offline
Member
"No problem cutting coax live or not. What is important, at least in my industry, is to use special coax cutters as not to deform the coax."
___________________________________________

What industry is that? Cut my coax when i am operating CW and you will light up.

Joined: Oct 2003
Posts: 156
D
Member
LK, good point I should have qualified my statement with low power line level signals. I am in the Telco buisness, and we mostly deal with DS3, some micro and a lot of wireless telephone. Yes if you were to cut a coax with a transmitter on it you could get burned.

Joined: Feb 2003
Posts: 687
A
Member
One place I was at had an prize of shame for the bigest mistake. I remember one guy got it for cutting a RG-6 for a home sattilate system. I guess it burned out the dish reciever.

Tom

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