hey guys does anyone here use a tester of some sort to test 70 paging,i'm usually pretty good a fault finding but i'm stumped on a short in a walmart there are splices all over the place just wondering if there is a tester that could show a short on the line
thanks

https://www.gold-line.com/zm1.htm

Thanks Jeff
but that thing is more for sound quality testing and not finding a short but an interesting device

That will work to find shorts by checking the load of a line but there are cheaper meters that do the same.

we used to place a condensor in series with a tone and use the probe.

No. Not for sound quality testing at all, it's exactly what you need. It's an impedance meter that measures the impedance of the line which includes all the transformer taps. It will indicate a short as well as the actual load on the amplifier if there is no short. You use an impedance meter to measure the impedance of inductive loads in the same way you use an ohm meter to measure the resistance of resistive loads. You cannot use an ohm meter on inductive loads like this. It will always measure close to a short because it uses DC and all you are measuring is the wire resistance of all those transformers in parallel on the line. An impedance meter uses an AC voltage.

Off hand I know of nothing cheaper but there might be something. I don't see how a capacitor and a toner/tone probe is going to find a short Jim. It will allow you to trace the wiring though.

Problem you are going to have is even if you know there is a short where is it? No such thing as a TDR for this. I'm afraid it's going to have to be visual inspection so start popping those tiles up. If you have an impedance meter use the divide and conquer method. Also look for speakers connected directly without transformers. Those $2/hr employees in the stock room like their music.

-Hal

And sometimes it's just the store maintenance guys that hosed it when 1 speaker went bad and they scrounged a speaker from returned equipment. In any case, it's almost always a single speaker. Sometimes wiring, usually damaged during other maintenance. Occasionally the amp, but they usually don't go bad without 'help', so look for wire or speaker problems if the amp is fried.

I'm almost afraid to tell you this but there is an easy way to find and eliminate rogue speakers on the line. Simply disconnect the wiring from the amp and apply 120 volts to it for a second or two. The speakers with line transformers will just make a lot of noise and not be harmed, but the voice coils hung on the line will, shall I say, not be a problem anymore.

-Hal

HMMMM! Interesting technique!

Hal, that's very clever. I think OSHA might object,

But I approve.


Sam

I learn so much here!