air testing my MXT

[Steeler1]

Air tested a .25 in c/j mode with max gain. It will have a very, very faint disruption in the threshold at about 9 inches. So faint in fact, I'd never even notice it. And it never lets me use max gain anyway.

When I reduce the gain to preset level, I get the same barely noticable disruption at about 6 inches, again so faint I'd never notice it.

Since most of the time I must lower the gain to about 7-8 for the machine to run smooth, no wonder I cant find anything deep. It air tests at 5 inches with gain at 7.

What gives? Does this sound normal?

 

[Cfmct]

Doesn't sound normal to me... I have found on occasion dimes down to 14 inches... but they were just whispers... I would call whites and you might have to return the detector for service. are all your connections clean and tight? Rudy from the board is very knowledgeable I'm sure he will chime in.

 

[jeff@middlesex]

I usually go outside ground balance the machine leave it on come inside and test it.

 

[Rudy]

Hi Steeler,

What were the conditions of the air test?

Which coil? Was the GB locked? Where you using an
in-out motion, or moving the quarter across? ...

BTW: Air tests are not very indicative of in ground performance.

 

[OkieDigger]

BTW: Air tests are not very indicative of in ground performance.

Very true! The best test for you to do is bury that quarter down a few inches and test. I've tried air testing my MXT and the results are questionable. But I've dug coins between 8 and 9 inches (measured) in some packed soil.

 

[DeepBeeps]

I've found that my MXT will find coins at about 9 inches max ( faint beep and only one bar on coin indicator, but very repeatable). It could be possible that there arent any coins deeper then that around here, but I doubt it. The MXT can be very unstable much over gain preset. It still works but is aweful noisy.

 

[Steeler1]

  I've found that my MXT will find coins at about 9 inches max ( faint beep and only one bar on coin indicator, but very repeatable).  It could be possible that there arent any coins deeper then that around here, but I doubt it.  The MXT can be very unstable much over gain preset.  It still works but is aweful noisy.

Indeed. And around here it is unstable even at preset.

I am going to bury some coins tomm at about 7 inches, try diff settings, and see what happens. (after I make sure the ground is clear) I will post results tomm after work.

I think a new coil is in desperate need. A quiet(er) coil and one good at trash separation.

5.3 Eclipse a decent choice?

 

[Steeler1]

Hi Steeler,

What were the conditions of the air test?

Which coil?  Was the GB locked?  Where you using an
in-out motion, or moving the quarter across? ...

BTW: Air tests are not very indicative of in ground performance.

Stock coil (950), and no i did not have the gb locked. And I was sweeping the quarter in diff ways. Top to bottom, as well as side/side.

Im gonna get a new coil reguardless of this one being bad or not. But I will be doing some more tests tomm.

I wish you lived next door, Rudy!

 

[Stainles Steal Rat]

My friend has a MXT he can pick up very soild wheaties at 6-7 inches. I am sure I have seen him get a quarter at 8 before. He is almost alwasy dead on the target id, he won't dig zinc pennies but he will spot them for me all the time. Once in a while I dig a dime at 4 inches that he though was penny or a nickel he thought was a pull tab.

 

[Rudy]

Steeler,

One very good reason for not air testing an MXT inside the house is its sensitivity and operating frequency.  The MXT runs at a nominal 15 KHz (actually 14.7 KHz) frequency.  The television sets in the USA have a horizontal oscillator operating at 15.625 KHz. If there is an operating TV set anywhere nears the MX, it will pick up that oscillator frequency and go bonkers. 

Yes, the TV's oscillator radiates like mad. As a matter of fact, in England, where the TV system is slightly different, their TV's oscillator runs at 15.7 KHz. At one time, you had to buy a license to run a TV receiver (don't know if they still do that). The way they enforced it was to drive around in a truck with a receiver tuned to the 15.7 KHz frequency, looking for unlicensed televisions.   Fluorescent lights are another excellent noise source, as are many electric motors.

Sorry for the digression, just wanted to point out some of the many pitfalls in air testing an MXT indoors.

I also need to call out your attention to the notice on page 7 of the MXT manual:

* SPECIAL NOTICE
If you attempt to demonstrate or test the
MXT by waving targets in the air in front
of the search coil, it is ESSENTIAL to
have the GROUND BALANCE toggle in
the Lock position, NOT Ground or Salt.

This is necessary, for when the MXT is in
the Ground or Salt positions, the search
coil must SEE ground while it is passing
over the target or it will think that the
target IS ground and will attempt to track
it out. This is the case in all MODEs.

You may, however, demonstrate the fast
ground balancing feature of Ground or
Salt by waving or pumping a mineralized
rock in the air in front of the search coil.
Testing the MXT with targets while in
TRAC Ground or Salt positions must be
done in or on the ground.

If the reason for the noisy operation of your MXT is partly due to your ground conditions, I would not recommend the 5.3. Instead I would go with the 6X10 DD for depth equivalent to the stock 950, or the 4X6 DD for optimal trash separation (at some loss of depth).

Good luck.

 

[Brian]

My old site had the air tests figures for around 160 machines (silver,alloy,copper plus a gold ring). Constant comments were made that it provided no true indication of in ground performance (though I also had 'in-ground figures for both low and high mineralisation).
The intention was to show maximum performance as with most machines you are unlikely to get near the air test results. Figures were at one time provided by the major manufacturers but sadly they moved away from doing it perhaps because hot and distinctly cold machines were and still are being produced. With a high range machine the performance difference could be as much as two inches which accounts for why some think model X is great and others just average.

Still need the licence for T.V. Rudy but then you don't have to sit through adverts. They did scrap the licence for metal detecting though as it cost more to administer than they were collecting.

 

[jeff@middlesex]

steeler if you do get a coil get a DD. They are very hot.

 

[OkieDigger]

I love my 8" Excelerator DD coil. I can boost the gain to +2 in many areas around here without getting much noise.

 

[Steeler1]

I love my 8" Excelerator DD coil. I can boost the gain to +2 in many areas around here without getting much noise.

I seen one for $189.  Is that a good price?


Oh and Rudy. Any experience with this coil? Would it be good for me? +2 and not much noise, I'd be in heavan.

btw my friend, I never said I air tested indoors. I was out at my picnic table in the yard when I got the results previously posted. I did however, not have it locked. But it don't matter to me anymore, as I really want another coil reguardless.

 

[Rudy]

Hi Steeler,

I guess I assumed (incorrectly) that the air test was indoors.

I don't have first hand experience with the KCo Excellerators. I do know two other hunters that bought them, plus there has been much written about them in the forums. To summarize the forum posts:

Some people swear by them; Others have had mixed experiences; No one gets anywhere near the depths claimed by KCo in their advertising.

Of the two hunters I know personally, One is happy with it, the other got a coil that turned out to be defective (not water tight) and sent it back to KCo for a refund.

I myself use and like the White's 6X10 DD and the 4X6 DD. The MXT does run quieter with DD coils.

 

[OkieDigger]

Steeler, I think I paid $99 for mine. It was last year when KCo was selling them really cheap with a detector purchase. I also bought a 14" Excelerator ver.1 coil (used) from someone. Here's what can tell you about Excelerator coils. The 4.5"x7" is awesome. I have personally used this one. The only problem with it is the depth indication on very shallow objects (1" to 2" deep). It always says they're two to three inches deeper than what they really are. And for a small coil, it will go deeper than most its size. The 5" Excelerator I hear is very good as well. I've not personally used one though. I own and use the 8" coil 95% of the time. It's awesome. I've had no problems with it whatsoever and I've used it in shallow water as well. There are two 14" Excelerator coils. Version 1 which I bought is complete crap. You're lucky to get 4" of depth with it. It's noisy as @#$! and basically makes you want to wrap it around a tree. I bought the White's 14" DD to replace it. KCo doesn't make Excelerators. Detech is the company that does. It's German I believe. KCo is their distributor here in the US.

Rudy, as far as depth goes on my 8", I can tell you right now that it does go deep. I have no doubt in my mind that it will go as deep as the stock 950 coil. I've dug wheats at 8.5" inches (measured) with this coil in dry hard packed Oklahoma soil. Now, I will say this, Oklahoma has some really good soil for detecting where I am, so that helps.

 

[jeff@middlesex]

I think all DD coils have a problem with accurate depth reading the really shallow stuff.

 

[OkieDigger]

The 8" does pretty good actually. The White's 14" coil does too. It only seems to be the really small coils that have the problem (in my experience).

 

[Rudy]

Digger,

I didn't say they are not deep (in general), I said that they don't go as deep as the KCo advertising claimed.

[Rant]
When they first came on the market, KCo claimed incredible depth in their web ads. Now those ads have been toned down a bit and they use "user reports" and misleading comparisons.  In reality, they are not really deeper than White's own, given roughly same size coil comparison.

The above image, taken from the KCo web site claims, for example, that the 14" DD is twice as deep as the stock coil. Well, it better be deeper! The stock is only 9.5"! I have pulled mercs at 9" with the stock coil. Am I supposed to believe that this coil will find a merc at 18" ? Is it that much deeper than White's 1400DD ? I'd like to see a side by side comparison substantiating that claim.

When the Excellerators first came out and where being heavily advertised, one of our infamous California gang, Greg Moscino (if you saw the White's "Treasure Hunting America" videos , he was in episode 1 hunting in Golden Gate Park) asked KCo to let him borrow an Excellerator for him to test and produce an unbiased test report (he's done several field test reports for White's and others, as well as being one of the pre-production testers for the M6). KCo would not do it.
[/Rant]

Yes, the Excellerators are made by Detech and KCo is the exclusive distributor for them.

Now Digger, concerning your 8" going deeper than stock, I believe it. My 6X10, in my typical ground conditions, goes deeper than the stock .... because I can run it hotter than the stock coil and still get a stable threshold. In the areas where I usually hunt, the ground VDI runs into the high 70s low 80s. With the stock coil I may have to back off the sensitivity to 8 or 9 to keep a stable threshold and the chatter to a tolerable amount. With the 6X10, I can run it in the + region. Ergo, it goes deeper.

If I was fortunate enough to hunt in a low mineralization area where I could max the gain with the stock coil would the 6X10 still be deeper? Doubt it, but it would still cover a wider swath of ground, at near stock depth, under those conditions.

As far as indicated depth, the meter is calibrated for the stock coil. When you put the Excellerator or another size White's coil, the depth indication will be off. Easy to get used to. No big deal.

PS: I had the 1400 DD. Excellent coil for depth and wide open spaces. I wound up selling it because of the weight. I felt I was swinging an Explorer.

 

[Steeler1]

Thanks for all the time you guys spent answering my questions.


  I went back out today and did some more air tests. This time I did lock the MXT in a clean area. I turned the thing to max, and results was similar to the before tests.

  A ,25 in c/j mode, with my stock coil, max gain.  I barely heard a thing at about 7 inches.  Then at 6, it was a good sound.

  If it performs this poorly in air tests, all I can think of is no wonder I can't find a deep target. My machine don't allow me to do so.  Plus, I can never run my machine above preset anyway, to even find something at 6 inches. lol

  I'm off Saturday and am taking this thing back to my dealer to get some answers. My prizm IV air tests exactly the same as my mxt. 

Now whats wrong with this picture.