5" CZ-3D coil

Whilst at the detector dealer getting my goldbug 2 fixed, I had a snoop around in the coil box.

Guess what I found a 5" multifrequency old coin digger coil.
Very happy indeed,... because I just love my cherry picker CZ.



Time and weather permitting I'll fire it up and see what I've been missing.

HH
Johnb

I've managed to work in between some really old sqaure nails and find some really nice buttons and coins with that coil.
A nice addition to the arsenal.



Edited 1 time(s). Last edit at 02/12/2013 06:25PM by Aaron.

John,

Using the stock 8" coil on your CZ.............. see how a handful of nickels (one at a time) ..... ID's on your CZ. Then.............. switch to the newly discovered 5" CZ coil............ and repeat the test. (There's a reason).

I managed an indoor air-test, small coil seems to drop some coins into square pulltab box.
Now that is weird?

Anyhow,... when I'm going digging a few of every tone will get dug, even iron.
Just to see what is going on.

HH
Johnb

From experience remember you can usually run your sens. higher and get extra depth and certainly an asset in trashy areas and worked out areas where large coils just won't go (edges of sidewalks, near obstructions, around trees)...well you get the idea....certainly light and you really learn what overlapping means...

"Square pull-tab" ??? Are these nickels........ or other coins?

No,... they weren't what you guys would call Nickels.
A 5 Belgian Franc 1980 something Cu

I've only found a single coin what I think would class as a nickel.
1965 1 French Franc Ni it registered beavertail pulltab if I remember correctly with the 5" coil.

Anyhow don't read too much into it. Airtest was only to give the coil a go.
Everything works, behaves differently from the 8" coil,... so every tone will get dug until I understand what it is telling me.

Now, ... how about some decent weather!!

HH
Johnb



Edited 2 time(s). Last edit at 02/13/2013 09:33PM by scoopjohnb.

NASA-Tom Wrote:
-------------------------------------------------------
> John,
>
> Using the stock 8" coil on your CZ..............
> see how a handful of nickels (one at a time) .....
> ID's on your CZ. Then.............. switch to the
> newly discovered 5" CZ coil............ and repeat
> the test. (There's a reason).


--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Hi,,,Don't keep me hanging on this one inquiring minds need to know............Thanks....JJ

Of all the coils for the CZ........... the 5" coil is most likely (highest probability) of having a impedance mismatch. The first area it will be noticed...... will be in greater inaccuracy in reference to target ID. Since the nickel icon/window of a CZ is the tightest/narrowest in the industry........ and is a mid/low conductor.......... this presents the easiest area for the owner/operator to test impedance match/mismatch.

Sunray coils can easily have the same error.

If you heavily depend upon target ID..... this can pose a major problem.

This issue is not exclusively isolated to CZ's; rather, all brands of detectors and coil combo's. However; the CZ platform is one of the most ID (conductively) accurate units on the market (tightest ID tolerance); subsequently, err is more readily witnessed.

If you take a AT Pro, E-Trac, V3i......... using the same nickel for reliability testing.............. then keep swapping (testing) different coils for each brand unit............. you will notice variations in nickel ID.

This is why............ when someone sends me a unit to be calibrated/validated/certified........... I request the 'primary' coil. This should be the coil that came with the unit (stock coil).............. or the coil that you use the most....,,,,,,...... of which, then, I will calibrate the unit to that specific coil.

Tom did the rest with my 5" coil on my CZ3D. Used 16 dug nickels all came in as high tone except one shiny one that bounced between high tone nickel and round pull tab. Is this normal and the way it is suppose to be on a well tuned CZ3D?

For 'dug' nickels......... that is a good resultant/ratio.

Hi,,,So am I to take it that the older nickels in the ground are still going to high tone???? What about other denominations of coins???? I tend to dig only high tones maybe that's not a good plan for any future hunts....I would test my 5" coil but I'm not certain it's functioning properly as I only get 8" in an air test.....According to what I read that's not right....JJ

jj............ a properly tuned/correct 3D will ID nearly ALL older generation nickels as 'high-tone'. Newer 'undug' unoxidized nickels are less reliable.

If your 5" coil is good for about 8" on a dime............ may I speculate that your 8" coil is good to only about 10" ??? If the 8" coil is closer to 12" on a clad dime........... then the 5" coil is in error.

Hi,,,You tuned it Tom and specified it attaining 11.? in the ground....It probably would air test 10" to 11" and hitting both ways plus displaying proper ID with no problem....Thanks....JJ

Okay........... sounds like the 5" coil is in error a bit. I did not look up the spec's of your unit in my notes.

Hi....When I tested this 5" coil I left the settings the same as the 8" coil....The wire on this coil did have splits all up & down it so I contacted the Fisher company regarding this issue and they basically told me to take a hike....I put a new outside covering on this coil to cover the splits....Maybe something internally is wrong on this coil??? Thanks....JJ

It may still be okay....... as long as moisture has not penetrated the inner insulation of the actual wires. But......... still concerned about impedance.

Sounds like I'm going to need another CZ-3D to go with the 5" coil, then let it take at trip to the USA.
No hurry though,... still need to take it out for a field-trip.

HH
Johnb