White's Classic

[Ken in NC]

Was wondering if the Ground Balance for this machine is fixed in the Disc Mode?

I know the Ground Balance can be adjusted internally, as well as the Threshold. Would this just effect the pinpointing mode

 

[GoGoGopher]

I did this mod on a Classic II, and it seamed to effect DISC and PP modes...

HH,

 

[Monte]

tied in with the internal Ground Balance trimmer. If you have a Classic III SL or an IDX or IDX Pro, make sure the Frequency Shift is in the factory preset setting, fully clockwise) before you adjust the GB trimmer. If you use and adjust the Freq. Adj. trimmer it will shift the GB a bit and could cause falasing from being too negative. That's why I leave it at the Preset, and why it's a good idea to have Mr. Bill mode the Classic. That will provide an external Ground Balance and Threshold control, therefore making it easy to quickly re-adjust the Ground balance should you need to shift the Freq. Adj.

Also, when you adjust the GB trimmer on the Classic in the All Metal mode, make sure you do it over the most mineralized ground in your area, AND do not set it too positive or too negative. It needs to be just slightly positive in All Metal as the GB reference for the Disc. mode is quite touchy. If the GB is too negative in All Metal, it will be even more so in the Disc. mode and false a lot, especially over more mineralized ground.

Once you GB slightly positive (slightly) in the All Metal mode, then the Pinpoint function will work fine. Just keep the search coil level with the ground when you move off to the side of a target, then pull the trigger toggle.

Monte

 

[Ken in NC]

I suspected the ground balance must have an effect on the disc mode because of the success of Mr Bill's mods on these machines

Monte, thanks for the tips on setting the GB and especially for the tip about the frequency control. I was not aware that it could upset the GB

 

[GoGoGopher]

I was also unaware of the frequency shift as my CL II never had that feature, but I agree 100% about having the right GB in ALL METALS before entering DISC mode...If your too negative, your gonna false all day long, too positive can be bad too, but a little off on the positive side is where ya want to be, but not too much...I was told that if you have the stting right in the All Metal Mode, that when you switch to DISC mode, you want to hear a sound as you pull the coil off the ground, but not when you pump it to the ground....Was that correct?

HH,

 

[Monte]

I was told that if you have the stting right in the All Metal Mode, that when you switch to DISC mode, you want to hear a sound as you pull the coil off the ground, but not when you pump it to the ground....Was that correct?

No, that is incorrect. If you have a negative Ground Balance then you will get a false signal when you raise the coil from the ground. Equally, you'll get a false signal when you move the ground away from the coil, such as if you dig a plug to retrieve a target. Re-sweep the plugged hole and you get a louder beep!

In All Metal you should have the GB set just slightly positive and that should eliminate any falsing in the Discriminate mode. Always try and find the most mineralized ground in your area to set the GB trimmer. It is a fragile electronic control and can be damaged with excessive adjustment. Trying to adjust the GB trimmer isn't very difficult, but it isn't very easy, either. If you have 'Mr. Bills' modifications, all GB is quick and easy. Plus, if you're like me, you can get a very good functional Ground Balance in the motion Discriminate mode by using a technique I termed Power Balancing almost a couple of decades ago.

With many Tesoro models a "Power Balanced" Ground Balance setting for peak performance in the Discriminate mode means the All Metal mode is slightly negative. If you set a good All Metal GB to be just slightly positive, the Disc. mode is extra positive. Not so with the Classic series as they usually cal for just a very slightly positive GB in All Metal to be very functional in both modes.

Another nice thing about the basic Classic circuitry design is that they work well even if the GB is off a little, such as maybe somewhat extra positive. After using them for years I can move from one location to another to another around here, once I have a slightly positive GB over the worst ground, and I never have to tweak the GB. The only times I relied on the manual GB (I had most of my III's and IDX Pro's modified) was when I had interference from a nearby detector or other source and needed to adjust my Frequency Shift. I'd eliminate the 'noise' then quickly re-balance slightly positive. The other time was when I changed search coils due to some differences from one coil to another.

Anyway, just adjust slightly positive in AM mode and there won't be any audio response when bobbing the coil over bare ground in the Disc. mode.

Monte