Well, went back to the same site where I posted, "perfect settings for this site" and hunted a small area not more that 60' from the prior hunt. Used the same settings "GB 5, pulse 10 and gain max" and off I went. After a short while I noticed a lot of clipped or inconsistent audio reports. Decided at that point to reduce gain to 7 and continued. Hunted a few more feet, still clipped audio, strange, so I stopped to analyze the area a little more closely. Sweep in one direction and get a some what good audio, but the return sweep was either silent or chatter. Suspecting something was the cause I stopped and increased the pulse delay up a tad, nothing changed. Continued to increase the pulse until I reached 17 and suddenly the audio came through as a loud, almost overload low tone. Thinking it might be a nail, I dug and out comes a copper penny at less than 4" deep. Now to say the least, I was excited and puzzled.
Decided to start over where I started hunting and experiment using a pulse rate of 17. A few moments later came the same type of loud low tone. Thinking there is no way I missed that one my first pass I changed the pulse to 10 and the signal all but disappeared. Increased the pulse to 20 this time and spent over 5 minutes rotating around this target checking from every possible angle to see what might be causing the anomaly, switched the conductivity switch to all and still a consistent low tone with nothing else mixed in. Now one must keep in mind I'm using the stock 12" and at times it is very difficult to exactly pinpoint where the target actually is. Changed the pulse to 10 and and the low tone practically disappeared. Now I was wishing I had brought my Deus to recheck some of these inconsistent signals, maybe next time. Well anyway I dug a nice plug and out comes a wheat penny at less than 5" deep. Excited to recover something from an area that quit producing years ago.
Continued hunting with settings of pulse 20, GB 5 and gain at 7, and found many more coins dated in the early 60's all within a 3' path some 60' long. Already planning what I'll do my next hunt.
What I learned from this hunt:
Don't assume you have the best settings for any site especially the sites where coal waste has been discarded for many years.
I'm suspecting the partial or complete cause of the anomalies are the small BB size waste particles from the coal fired furnaces that will easily attract to a magnet . In fact dropping a strong magnet into the same hole where a coin was revealed exactly that.
I'm relativity sure I need a mono coil, but undecided as to what I'll get.
More reports to come.