CZ-21 Airtest Results

[cdv1]

Cold and snowy today and nothing to do. I had a request from another member to see how my CZ airtested a dime so I got a little carried away with my testing. Figured it might mean something to someone else and it killed some spare time while I wait for spring....

I got some interesting results.... I used both silver and copper coins and also clad coins. I used all denominations that I had, wheat penny, silver coins up to a silver Morgan and the whole line up of clad, zinc to clad half. Wrote down all the settings for each test, did the test in Auto Tune and in Disc 0 but also found out that the speed of the coin swing had a difference on the results so I added slow and fast swings to the test.... amazingly the fast swings actually hit deeper than the slow swing! I would have never thought that but it was consistant across the board with the faster swing, deeper results IN AIR.... now would it be the same in dirt or sand

DISC was deeper than Auto Tune too! I thought it was the other way around but not in my tests.

Three times trying to make it look good and it is a bit jumbled up..... can't post the word doc I have it in. If anyone is interested in the data in a word file, just PM me your email address and I'll send it on to you. It is easier to read that way!

Here are the results:

Cliff


CZ-21 Airtest

Settings: AutoTune, Volume 5, Ground 5, Sense 5
Copper & Silver Zinc and Clad
1c 7” 7”
5c 6” 6 - 6 1/4”
10c 6 ½” 6 ½”
25c 7” 6 ¾”
50c 7 ½” 7 ¾”
$ 8 ½”

Settings: AutoTune, Volume 10, Ground 5, Sense 5
Copper & Silver Zinc and Clad
Slow - Fast / Slow Fast
1c 7” - 8” 7” - 8”
5c 6 ¼”- 6 ½” / 6 - 7”
10c 6 ½”- 7 ½” / 6 ½” - 8”
25c 7” - 8” / 7 ¼” - 8 ½”
50c 8” - 9” / 8 ½” - 9 ½”
$ 8 ½”- 10” /


Settings: Disc 0, Volume 5, Ground 5, Sense 5
Copper & Silver Zinc and Clad
Slow - Fast Slow Fast
1c 8” - 8 ½” / 8 ½” - 9”
5c 8”- 9" / 8 ¼” - 9”
10c 8” - 9” / 8” - 8 ½”
25c 9” - 9 ½” / 8 ½” - 9 ½”
50c 9” - 10” / 9” - 10 ½”
$ 9 ½” - 10 ½”/

Settings: Disc 0, Volume 10, Ground 5, Sense 5
Copper & Silver Zinc and Clad
Slow - Fast Slow - Fast
1c 7 ½” - 9” / 8”- 9”
5c 7 ½”- 8 ½” / 7 ½”- 8 ½”
10c 7 ½”- 8 ½” / 8”- 9”
25c 8” - 9” / 9”- 10”
50c 8 ½” - 9 ½” / 9” - 11”
$ 9 ½” - 11”/

 

Amazon Forum Fav 👍

Cry Of The Eagle: History And Legends Of The Cherokee Indians And Their Buried Treasure - Grab it through Amazon!

[Sandman]

Good test results on the Cz21. I find the AUTOTUNE not as deep either, but more sensitive to smaller gold out to the side of the coil also. I still like to hunt in Disc be because it hits harder with more sound. Mine isn't great on tIny gold chains like a Tiger Shark, but can find those small earring studs and backs.

 

[gleaner1]

cdv1, great post, I always knew the cz20 liked a faster sweep. Simple air tests prove it. But I got a bit of disagreement from some heavy hitting senior cz users about this subject on a similar post not long ago. I think what they meant is that the machine is slow in the recovery department, so you have to slow down in the trash to get the best results, and I agree. Having said that, if you are getting a bit of and iffy signal, just waggle that coil over the target quicker, the machine goes a bit deeper, just enough to make an iffy signal pop out of the iron into the mid tone. Like deep green indians, they get your attention, but if you don't waggle quickly over them, you might pass them up as deep iron crap. In reality, almost any VLF gains depth with an increase in sweep speed, it is not a brand specific phenomenon. On the cz20, this phenomenon is even more evident in all metal autotune, where a faster sweep speed makes it scream louder and hit max ear piercing pitch.

 

[U.K. Brian]

I did a sweep speed test a few years ago with ten or eleven "standard" VLF's plus a Minelab Sovereign and a Fisher CZ6a and the results were very different. In almost every case an increased sweep speed cost depth and increased falsing.

But this was in soil where the finds are, not air.

When the CZ-3D came out it proved to need to be swept slightly slower again than even other CZ's for the best performance. Nasa Tom was very quick to point this out.

The exceptions to the slower sweep is best rule (though there is a point where even a slow sweep two filter detector can be swept to slow) are as you would expect with four filter detectors like the Whites Spectrum and XLT.

 

[gleaner1]

I did a sweep speed test a few years ago with ten or eleven "standard" VLF's plus a Minelab Sovereign and a Fisher CZ6a and the results were very different. In almost every case an increased sweep speed cost depth and increased falsing.

But this was in soil where the finds are, not air.

When the CZ-3D came out it proved to need to be swept slightly slower again than even other CZ's for the best performance. Nasa Tom was very quick to point this out.

The exceptions to the slower sweep is best rule (though there is a point where even a slow sweep two filter detector can be swept to slow) are as you would expect with four filter detectors like the Whites Spectrum and XLT.

U.K. Brian, I must respectfully argue with you. The machine of topic is a cz21, not a 3d. I do not understand what a "standard" vlf machine is, would you elaborate? The OP's air test results on the 21 prove what I have observed in the field since '93. It's a simple matter really, beyond argument. Anyway, starting from zero sweep speed up to a fast sweep speed, vlf machines respond better the faster you go up to a point, then it is too fast. If I had to rate a speed from 1 to 10, ten being too fast, the cz21 is a solid 9.5. One man's fast is another's slow. The cz21 should never be thought of as a slow machine, unless you want to miss deep stuff.