CZ-70 Question

Ever had one that was a little out of tune? My first 70 seemed to classify targets and lock on better than the one I have now. This one likes to jump between two catagories a lot. I have tried with the 8" and 10.5" and it does the same with both. Can or will Fisher still work on the older machines? Thanks.

Lifetime Warr..... yet, I'm uncertain that FTP would give it a tune-up. Time permitting, I'll ask Mike Scott (FTP).

Tom

Tom - How do you know if a detector is out of calibration? Are there anyway warning symptoms?

Since you are on CZ 70 – while rereading you excellent response to the CZ evolution – I noticed you said that Sens should be 6 or less. Is that true for beaches and other areas?

CZ-70 = Place volume on '10', Sens on '10' and invoke "autotune" (all-metal) mode. Unit should audibly have a light threshold 'hum' ---- both in "Salt" mode and in "Normal" mode.
All CZ's utilize specifically low conductive nickels and fairly high conductive Zinc pennies as 'base reference' calibration set-points. As far as the U.S. mint is concerned..... ((the last 120 years of)) nickels and Zinc pennies are compositionally extremely stable/repeatable/accurate in reference to hair-splitting conductivity between similar coins and batches. (Exclude WWII silver nickels). Soooo...... With that said:

A U.S. Shield nickel (1866 - 1882) that has NEVER seen dirt/corrosion can be waived in front of a CZ-70...... and it should bounce between "foil" and "nickel"..... a mid-tone to high-tone bounce,, as long as coin is flat/parallel to coil. (Some perfect Shield nickels do indeed read a constant 'foil'). DO NOT TILT THE COIN. A dirt-dug shield nickel should always ID as foil.

Indian Head pennies are slightly lower in conductivity than a modern Zinc penny,,,,,,........ So.... they are more likely to bounce between "Relic" and Zinc penny. Take a (say 1902) Indian Head penny that is NOT dirt exposed and wave it past the coil and it should constantly ID as "Zinc penny". NOW...... Start tilting the penny as you wave it past coil. The CZ-70 should start to bounce between 'Zinc' and 'Relic' tones & icons once the coin is approx 45Deg (or greater) tilt. Remember; Indian Head pennies are at the very low end of the Zinc penny conductive window.
...Hold the coins at an average range from the coil. Not too close or too far away.

FTP spanks me each time I say the following: A proper CZ-70 can air-test a U.S. dime @ 11-1/4". Some may air-test out to 11-5/8". Detector must be in "Normal" mode with Sens on '6'. This is with the ORIGINAL coil (8"). CZ's are very powerful..... and the CZ-70 batches are also quite reliable/similar/repeatable.

In fact... all of these validating tests are performed w/8" ORIG coil.

.... On a different note; With a digital platform CZ,, if you are hunting the beaches in ID mode.... try to run Sens on '6' or '4'. If you are in the all-metal mode ALWAYS try to run Sens on '10'.

Tom

Hi Tom,thanks for your advice. I set my machine up as you described and found that I have no threshold hum. Then I set the machine up to do the dime test and got 9" max. Tested some modern nickles and they bounce from nickle,tab,and foil. Seems the machine needs a checkup. Sure wish that I could buy a how to manual on how to tune these things. Hint, hint. I'm sure it's not rocket science. Sorry Tom, I just had to throw that in there. Thanks a ton and have a very Merry Christmas.

I contacted Mike Scott..... and he said that FTP could give your machine-in-question.... a tune-up.

Tom