VDI Variance Question and Coil Question

[ga5150]

Hoping you more experienced MXT users can give me some insight.

Got out for a few hours today and my vdi's were all over the board. It's like everything was off. Some examples: Bottle caps showing 70-74 (usually in the 50's for me), Zinc pennies showing as copper, found a half dollar and it showed as a quarter, Nickels showing 24-28 (usually 18-20 for me) and even had one nickel show up in the 40's as pull tab. The only reason I found that nickel is because at one location I was digging everything hoping for some jewelry.

I just put in fresh batteries this morning as my others were showing 10v when turning on. I ground balanced as always and rebalanced every 10-15 minutes or when having obvious terrain changes.

Anyone ever come across this and if so do you have any info on what may have been going on?

I was using my 5.3 coil that I usually use in the trashy areas. It pinpoints great, and the depths were mostly spot on, it just seemed my vdi's were whacked today.

I still found 8 wheats, an 1882 IH, a 1916 Barber dime, and my very first Barber Quarter-1897. Also, got a ton of pocket change. Anyway, it was still a fun day and I'll go at it again tomorrow!

My second question- I've read that turning the disc up will reduce my effective depth range. So, if I use my 5.3 coil and turn up the disc I'll lose depth. Could I use my 9.5 coil and turn up the disc and get the same effective depth as using the 5.3 without disc since the 9.5 coil should get better depth reading since it's larger in size? Hopefully that question makes sense.....I think I made it sound confusing!

Rodney

 

[Aarong81]

You had an awesome day as far as finds go! Congrats.
What setting did you use for sensitivity? Try your 950 and see if the VDI issue is machine or coil specific. But it sounds like your detector could benefit from a visit to Sweet Home for tuning.

About your second question...Short answer: The depth may end up about the same if you increased disc with the 950 vs normal disc with the 5.3...BUT....If you have both 5.3 and 950 coils and your chosing the 5.3 you must have a reason, very trashy area, ect. If thats the case, the 950 will lose the advantage right off the bat without the expected depth loss your referring to about increasing disc. In a trashy area the 950 will see multiple targets at the same time, add in the increased disc setting, and it not only nulls because of the multiple targets in the signal area but what it 'thinks' it see's is also limited by the muzzle your putting on it with the increased disc. With the disc turned up, the detector still sees everything but it will not audibly let you know. It does however show everything on the LCD as usual. I love the 950, I used the heck out of mine and eventually broke off the mounting ears on it. But if the area is very trashy the 950 is not very well suited for it. However, I have found out that if you hunt out a site as well as possible and then switch coils to nearly any other coil than originally used you will find a few missed targets. Its impossible to know how many good targets are hidden by a piece of iron or wrapped in some masking objects that a different coil can pick out easier. I like to start with a general use concentric coil to search it out then swith to a specialized DD coil to sniff out hard targets later. That way I know the specialized coil really does prove itself vs general use coils.

 

[ga5150]

Hi Aaron,

Thank you for the detailed explanation of my second question. I understand and it makes sense. I'll just stay with my little 5.3 in that area until I have it cleared out some more.

On my vdi issue, I usually keep sensitivity on the preset marking. However , today I turned it up to +1 and I've never used it at that setting before. I didn't think about it until you mentioned it, but now I wonder if that wasn't the culprit for me getting odd vdi's.

Thanks for your information!

Rodney