[TowerTalk] Coax questions

[Jim Brown]

On Sat, 28 Aug 2010 13:58:22 -0700, jimlux wrote:

>Most rental yards have a cable locator.  It comes with a little box with 
>a cliplead that puts a low frequency AC on the cable (or pipe) you're 
>trying to find, and the locator that looks for the signal.  Used all the 
>time with modern plastic gas pipes (typically with a wire wrapped around 
>it to facilitate this process)

It seems like it ought to be possible to improvise something that would do 
the job. One thing that would probably work is to drive the cable shield 
(end to end) with a 1kHz signal that is feeding an ordinary power amplifier 
(like what's in your home stereo) and look for it with a magnetic coil 
that's connected to a portable headphone amplifier. Two easy-to-use coils 
are 1) a dynamic mic; 2) a de-gaussing coil. 

Another possible test signal is a QRP transmitter running on 160M loading 
the cable shield as a long wire, then look for it on a portable RX. Even a 
signal generator might put out enough signal to be heard on a portable AM 
radio. 

73, Jim K9YC