Jim, I did not realize you had sent me a PM until last night. My boss happened to have a small strand of what looked like the wire. We had to go to the nasty lake hydro job and I fed about 100 feet of it into the hydro tube. We used his 521 and we were having issues picking up the signal from it, but I figured out why. We did not have enough wire to find the valve we were looking for (had a bad diaphragm), but we did find. Once we dug that one up and fixed it we had another. We used the same wire to figure out where the main was going to find the next valve! My boss was VERY impressed! I think he will be on this site soon...lol I am going to see if I can find the wire locally, if not I will let you know to see if we can figure out how I can get some. I attached pics below, you can see the rip in the diaphragm.