Every time those "disappearing signals" threads/questions come on the forum, from a newbie, I harken back to several situations I've had meeting-up with newbies in my area, who had the same complaints. I would try and try over the phone & emails to diagnose the problem, to no avail. Then we'd agree to meet, and immediately the problem would become obvious to me to diagnose. Things that could not be diagnosed in printed text or phone calls. I had to be there to see what was going on (the mistake that newbie was doing). No amount of printed text or phone calls can convey things like sounds, tones, swing speed, repeatability, etc.....
Each time they were silly things, that once we each traded off a few flagged signals, and I looked at what they were doing, we could both immediately see the issue. Here's 2 examples, but DON'T GET LOST IN THE EXAMPLES:
a) a guy has an XLT, which is a motion discriminator (with a fairly fast clip required, when compared to more modern machines). Whenever the guy would get a signal, he would "slow down to try to hear it better". But then lo & behold, it would disappear ! (unless it was really shallow). Why? Because he was no longer giving it motion. So he'd give up, and go on to the next signal, only to have it happen over and over and over! He sent the XLT back to Whites for "repairs" several times. Each time, it would continue to do the same thing. He read the instruction manual several times, and was fit -to-be-tied!
We finally met up, and I could immediately see the error. And I asked him : "I thought you said you read the manual several times. Didn't you see the part about 'motion required' ?". He said yes, he'd read that. But he just thought that meant moving the coil from side to side as you swing, while walking/detecting/progressing foward. And he had thought: "That's a silly instruction. HOW ELSE is someone supposed to ever get any detecting done, if they're not 'moving the coil in motion' . I mean, duh, did they think someone was going to stand there motionless with the coil in one place, not progressing through the field ?" But when I showed him what that meant (the faster the swing, the deeper you go), only THEN did the "lights go on". And prior to that, no amount of printed text exchange could ever have shown what his issue was.
b) Another time a guy & I were detecting at an abandoned military barracks. He got a signal at the corner of a building, and dug down. After 10 minutes of ever-deeper and ever-wider hole, he could STILL not find the signal. He called me over. In 5 seconds after a single swing, I immediately found the problem: The signal he was getting was some flashing within the inside of the wooden molding of the corner of the barracks. And the guy didn't know that the tip of his coil was sensitive to signals too. He kept assuming the signal was downward. Doh!
So your best bet for "dissapearing signals" is to hook up with someone proficient in your area, and trade off flagged signals to compare.
