:teknetics:T2 question...11" coil vs 5" coil?

[396nova]

What are the advantages for each coil? 11" coil covers more area and more depth? 5" coil better in trashy area with better TID?

 

[Elton]

Not bad on depth with the 5" DD coil either...

 

[TerraDigger]

396......here's a little bench testing on the 5" I did a while back....hope its useful to you. Personally I love the 5". Fantastic for co-located targets in trashy and not so trashy areas. Great depth for such a small coil. Plus you can use increased sensitivity and a slower sweep speed. Thats been my experience.

Model - Teknetics T2/Software version 6.5 (from 6.0 onwards version numbers make no difference in depth according to First Texas Products)
Coin Used - U.S. Quarter - Cupronickel
Coil - 5" DD
Sensitivity - 60
Tone Selection - 4

Discrimination Levels

0 - 9" depth reading (extremely noisy due to EMI & machines internal circuitry noise)
10 - 7" depth reading (approx 50% less noise than 0 disc setting)
21 - 6 1/2" depth reading (quiet)
30 - 6" depth reading (quiet)
40 - 6" depth reading (quiet)
49 - 5 1/2" depth reading (quiet)
50 - 9" depth reading (this is where another huge increase in Gain occurs, besides the zero setting. Same noise level as 0 disc setting)
60 - 9" depth reading (approx 50% less noise than 50 disc setting)
70 - 8 1/2" depth reading (quiet) (Tek Omega gets 8" at this sensitivity)
80 - 8" depth reading (quiet)

Observation - the Gain does not seem to follow a straight linear output as disc is increased. Notice that from 0-49 disc there is a 3 1/2" range in detection depth. From 50-80 disc there is a 1" range.

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If you remove the disc 0-9 results from above, there is a 1 1/2" depth range between disc 10-49 and a 1" depth range between disc 50-80.

The large gain increase at 50 and the 10-49 disc range has serious implications on how a user sets the discrimination. Below are object disc ranges on T2:

Here is a in-ground test with 11" coil in very mineralized ground. Test was done by Mal.....one of our British friends. The 177cal is a airgun lead slug used as a substitute for a gold nugget.

IN GROUND TEST

...........................................Sens....43.............................55
Disc................................................177cal.......................Cupro/Nickle Coin.....(British 5 pence/almost the same as a U.S. nickle)
0 ....................................................5

 

[Big Boys Hobbies]

What are the advantages for each coil? 11" coil covers more area and more depth? 5" coil better in trashy area with better TID?

You said it yourself perfect!