? can extreme temp. changes cause falsing in the GT

[deepdiger60]

Yesterday i was on a beach i started my hunt in the white sand it was very hot good thing i had sneakers on after a few minutes of hunting i worked my way down to the water it was low tide i waded out in about 2 feet of water , by the way i was in a Bay beach no waves right away the GT started to false each swing i was using the stock 10" coil in disc. mode sens about 11am 12pm no matter what i did it would not stop for about 5 minutes i tried to re-ground balance it no change , then all of a sudden it stop it went to a perfect threshold ? i remember reading once where radical temp changes can do that until the coil reaches its operating temp. This happened to me 2 times yesterday moving from water to sand vis - versa is that normal ? That is the first time that has happened to me in 3 years and i do not use a coil cover on salt water beachs. Jim thanks for any help .

 

[Critterhunter]

Did you read the other thread going on right now about the coil/temperture thing? It's a possibility. One part of the coil (like say the inner part) is still one temperture while the outter part is changing temps faster, thus the coil windings get out of balance with each other. That's my guess since you weren't using a coil cover to cause falsing by trapped sand/water under it. Could have also been random EMI noise that was bad in the area. Even some yoke driving by with a pimped CB could cause problems like that. I've had spots were EMI was terrible one minue and gone the next.

By the way, no need to ground balance if you are hunting in discriminate. Discriminate uses it's own unique form of compensating for the ground that doesn't require a ground balance, and it's not auto ground tracking like on other machines either. It's much better than that and unique to Minelab. You only need to ground balance for the all metal fixed mode by first using tracking mode to set it. Either sweep around for a few minutes in track and then switch to fixed, or pump the coil up and down slowly in a clean spot in fixed until the threshold stays stable from ground to air and vise versa, then throw it to fixed. Or, you can hunt in track all the time if the ground is changing fast but you won't get best depth compared to fixed as track can track out deep targets.

 

[deepdiger60]

Thanks Critter i only GB the machine in all metal then flip over to disc. , now you mentioned it there was a big cabin cruiser 40 foot going by not to far out that was the only waves maybe he had a powerful CB , the water temp was 65* still cool for this time of year ,it will be either wet sand water or dry white sand that should solve the problem if it be that , actually i got more in the white sand yesterday then in the water although it be a hand full of change , this weekend i take a short ride and hit the big ocean beaches . Thank,s for the information HH Jim

 

[Critterhunter]

Yea, maybe that boat was the problem Who knows what kind of electronics they have on it. Maybe even radar could cause the problem, as some large private boats even these days have forward looking radar on them to avoid obstacles. Also, the temperture thing doesn't necessarily have to be real hot or real cold. It's just that if one part is one temperture and the other another, the expansion and contraction of parts of the coil that are still at different temps than the other could probably put the windings far enough out of wack to cause instability until things equalize. Even if the entire coil is the same temp, if that temp is say too hot or too cold then that could cause the windings get move out of proper alignment I think.

 

[imalookin2]

Be sure your coil cover is cleaned out. Also be sure the connector is tight. You are hunting in the water at 11 o'clock is a bit hot. I run about 1 o'clock and get a false now and then. Running at your setting would not work on my machine on my salt beaches. I can run your setting on wet sand but have to lower it going into the water. Turn the sensitivity down until it stabilizes. If that does not work then it is something else. If the falsing is bad and then seems to stop then start it may be someone transmitting. It will false and stop while he waits for the reply. Forget ground balancing. It is never needed when hunting in disc or pinpointing.

 

[deepdiger60]

Be sure your coil cover is cleaned out. Also be sure the connector is tight. You are hunting in the water at 11 o'clock is a bit hot. I run about 1 o'clock and get a false now and then. Running at your setting would not work on my machine on my salt beaches. I can run your setting on wet sand but have to lower it going into the water. Turn the sensitivity down until it stabilizes. If that does not work then it is something else. If the falsing is bad and then seems to stop then start it may be someone transmitting. It will false and stop while he waits for the reply. Forget ground balancing. It is never needed when hunting in disc or pinpointing.

Thanks im your right i was running to hot that does not happen on Ocean beaches i guess Bay water has a higher salt content i ran it at 1pm and it did not false just a few spits . Jim