15” coil arrived

[vferrari]

Yak,

Official Minelab specs say that the 6" coil weighs 300g (10.6 oz.), and the 12"x15" weighs 650g (22.9 oz). I can't seem to find official Minelab specs on the weight of the 11" coil, though.

However, a user on another forum weighed all three himself; he found the 6" to weigh 303g (similar to Minelab's specs), and the 12"x15" to weigh 660g (again, similar to Minelab's specs). He said his 11" coil weighs 506g (17.85 oz.)

SO, if we assume this guy is "correct" with his 11" coil weight (and he was, on the weights of the other two), then it looks like the 12" x 15" coil weighs roughly 150g (just over 5 oz.) more than the 11" coil -- or roughly 29% heavier.

Steve

OP's numbers back that up from above

With my digital fishing scale:

11” = 13oz
15” = 18oz

 

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[devldog]

Took the words right out of my mouth. Too funny.

You know the old saying: "Great minds think alike." Lol

 

[rc2125]

When I weighed them, it was without coil covers, stock coil cover weighed 2oz with the fishing scale, didn't weigh the one for the 12x15.

After hunting with the 15 a few times, I was noticing it wasn't really hitting dug targets in dirt plugs at a distance that I expected it may have.

Did some air tests when back home to check it out and see what was going on. Long story short, actually a little less depth versus the 11" coil. All the same settings, same place, same targets at same time. I almost always start out using Park 2, Multi freq, Recovery Speed 5, Iron Bias 4, 50 tones, No disc, all metal on... Sensitivity 22, so I used these setting for the air tests. I grabbed a silver dime, silver quarter, war nickel, silver half, kinda hefty 14k gold engagement ring, a thin 925 ring and a size 13 silver band outa the finds pile and headed out to an interference free area out back.
Not into making videos, so just took pics with the targets placed where they still made a very solid, very repeatable signal. Not iffy or quiet or partially repeatable.

Stock 11"


12x15:


Yes I'm aware that iron bias and recovery can be lowered and sensitivity turned up for a little more depth, but that's my normal starting point with settings. Didn't mess around with larger targets. Just figured I'd post for reference. Will be wondering if anyone else see's similar results with theirs.


Had to try the 6" as well, later that evening with same targets/settings for reference also:

 

[vferrari]

Overall, not too surprised.

It's an elliptical coil with a short diameter only an inch more than the diameter of the 11" round. I expected the depth between the two to be comparable, perhaps an inch deeper for the 15x12, so though I am a little surprised it is showing up a little short vs. the 11", I chalk it up to the fact that air tests introduce a lot of variability and do not replicate true in ground conditions. As long as such a test is conducted with consistent settings across the board, the best you can show is that the two coils will perform similar to each other. So as long as it is "in the ballpark" of the 11" then I am not too concerned.

Variability in performance can come from the fact that the large coil may pick up more EMI than the 11" and therefore the signal processing circuit may have to compensate for that. It also helps that you show that both larger coils clearly outperform the 6" at depth, as expected.

Even though you did a valid apples vs. apples vs. apples test by keeping all the settings the same between tests, the fact remains that you have essentially provided only one air test data point. Performance may vary over the range of allowable manual settings and from mode to mode, so unless exhaustive data is provided for those other setups, not much can be concluded about relative performance other than from a depth perspective, the two larger coils have similar "in the ballpark" performance, as expected.

The 15x12 is really a coil built for coverage vs. depth compared to the 11", I really expect their depth performance to be similar and your test somewhat validates that.

Thanks for doing the test and presenting the data here.

 

[flgliderpilot]

Seems to me like Minelab did their research when they started with the 11" as stock size.

 

[A2coins]

Ive had the attack coil before it wasnt as heavy as you would think at all very well balanced and pin pointing was great, Dont use in trashy areas also some bigger coils you ground balance at 1/2 sensitivity Good luck gonna be a killer

 

[toasted]

I think Im gonna get one. My fields are HUGE