Answers needed on the CZ-20

[Sandman]

"Hello,
Back in the old days I knew how to open my 1280 and tune the sensitivity up so at max it was to high so when hunting I could cut it back to the exact point that I wanted for max depth.

Can this be done on the CZ20?"

I am posting this for another guy that is not a member and I didn't know the answer for him.

 

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[gleaner1]

Sandman, I thought you were an old pro with the '20. I have 18 solid seasons on the 20 so here I go. On the cz you set your sense, and then you GB to that sense setting. That's it! If the soil is so iron mineralized it wont ground balance, set the sens lower and try again. I'm lucky I hunt in loamy soils and limestone areas, I use max sense, it gb's okay and its stable. Not so in every situation. In my opinion, in mild soils, GB is only marginally important, if you are off a bit, you wont miss that 10" deep dime.

 

[Sandman]

Sandman, I thought you were an old pro with the '20. I have 18 solid seasons on the 20 so here I go. On the cz you set your sense, and then you GB to that sense setting. That's it! If the soil is so iron mineralized it wont ground balance, set the sens lower and try again. I'm lucky I hunt in loamy soils and limestone areas, I use max sense, it gb's okay and its stable. Not so in every situation. In my opinion, in mild soils, GB is only marginally important, if you are off a bit, you wont miss that 10" deep dime.

I know how to use the CZ-20. This other guy used to take his 1280 apart and soup up the Sens and Gain and wanted to know it that can also be done with the CZ-20. If you upped your settings inside you could turn down the Sens knob for minerized ground and turn it up beyond what all the other CZ's are running. I didn't know if that setting was possible with the 20 as it was in the 1280. Course you need to know how to open the box and what to mess with.... My 1280's are not set to factory specs. either.

 

[gleaner1]

Oh! I see, you guys are literally getting inside the guts of the machine, tweaking the electronics, playing with the innards to get max performance. I am sorry for the misunderstanding. I though something sounded weird when the user said he would "open" up the detector. The bottom line is that the cz is a very sensitive machine, even by today's standards, even after all these years. In my opinion, the old-hat cz20 will keep up with any machine, even its 75 offspring, sensitivity-wise.

You would be much better off splicing a big aftermarket coil into the cz20 to get greater depth, rather than try to tweak the electronics. If that doesn't work, you can always put the original coil back. The cz has so much going on inside that I would dread tweaking anything electronic. The only thing available to tweak is one of its 6 or more pots, and this machine has two separate boards packed full of IC chips and crap. You could turn it into a hospital case very easily. Maybe you could swap out the main sensitivity adjuster control pot, maybe change the ohm range a bit. That might work. All this may have been done on the cz5 series by somebody out there. I personally would not try it. No need for it.

 

[Sandman]

Gleaner you are right. Manufactures can make detectors more "hot" but the average hunter would find them to crazy and unstable to operate. Many guys always turn up the sens to MAX and wonder why they dig targets that aren't there. Also the larger the coil the more minerals it sees and you can also get less depth.

Back when Fisher wasn't owned by First Texas they would tweak up or down detectors for you. Install longer cables and off brand coils, different headphones, but not now.

 

[seeker41]

sandman, heres what tom dankowski wrote when i posted your question......

"Not recommended. You would require a O-Scope....and a long alignment procedure."

 

[gleaner1]

sandman, heres what tom dankowski wrote when i posted your question......

"Not recommended. You would require a O-Scope....and a long alignment procedure."

That's what I heard from Fisher in '95 concerning the 20. There was a thread not long ago concerning swapping cz20 coils. I still say that if the coil will work for a cz5, it should patch into the 20 without aligning the boards. If the coil ohms are right, it should work. Inductive effects come into play though. That has me a bit worried. Someone will try it, sometime, someday. At this particular time, I don't have the intestinal fortitude, nor the wallet.

 

[Lowbatts]

Gotta be a pawn shop CZ20 deal out there for the tech heads to play with. I'd really like a 6" coil on mine, but there simply isn't one. If I could get a coil that size, then I'd sure want that thing running hot.

 

[Sandman]

I think the Fisher CZ-6a is a land version sort of the CZ-20. I used to wade with mine till I got the 20 as the cables are long enought for neck mounting with the CZ-6a.

 

[bigscoop]

Been looking into larger coils for the CZ20-21, and I've gotten a lot of private and commercial feedback on the subject, given that, all I can tell you is that before I attempt it, "someone else needs to try it first!"

 

[seeker41]

I think the Fisher CZ-6a is a land version sort of the CZ-20. I used to wade with mine till I got the 20 as the cables are long enought for neck mounting with the CZ-6a.

cz5 is the land version of the cz20!! i have seen cz20s with the large cz coils spliced or hardwired on!!
if you want to keep your cz20 a cz20 i would not recomend trying to open the control housing at all!!!!! one misstep and you will have to send it in and have it converted into a cz21. not a bad thing but it will no longer be a cz20!!! sorta like having your 64 vette "upgraded" to a 2010 vette .

 

[gleaner1]

I have done coil wire surgery on my cz20 four times. It is not difficult to tear down a cz20, it's in fact easy. But it is surgery and you have to be ready for it. Good clean work area with good lighting. You will need a philips screwdriver, a bit of soapy water... and a bit of courage. Its not bad really. When, not if, I do it again, I will do a pic spread of all the steps. The cz20 is very susceptible to coil wire fatigue. If you come across a brain dead 20, I say it is 95% chance failed coil wire.

 

[Sandman]

I think the Fisher CZ-6a is a land version sort of the CZ-20. I used to wade with mine till I got the 20 as the cables are long enought for neck mounting with the CZ-6a.

cz5 is the land version of the cz20!! i have seen cz20s with the large cz coils spliced or hardwired on!!
if you want to keep your cz20 a cz20 i would not recomend trying to open the control housing at all!!!!! one misstep and you will have to send it in and have it converted into a cz21. not a bad thing but it will no longer be a cz20!!! sorta like having your 64 vette "upgraded" to a 2010 vette .

Thanks Seeker, I knew it was one of them..........

 

[bigscoop]

I think the Fisher CZ-6a is a land version sort of the CZ-20. I used to wade with mine till I got the 20 as the cables are long enought for neck mounting with the CZ-6a.

cz5 is the land version of the cz20!! i have seen cz20s with the large cz coils spliced or hardwired on!!
if you want to keep your cz20 a cz20 i would not recomend trying to open the control housing at all!!!!! one misstep and you will have to send it in and have it converted into a cz21. not a bad thing but it will no longer be a cz20!!! sorta like having your 64 vette "upgraded" to a 2010 vette .

So what is the largest coil (including after market) that can be safely spliced onto the CZ-20/21 without retuning? Been trying to get this answer for quite sometime but it seems nobody is certain? Or is it just not possible? I'm guessing that since nobody seems to know for certain there's a bit more to it then just splicing the coil in.

 

[therover]

Not sure about the re-tuning part, but I believe the biggest coil for a CZ would be the after market Sunray FZ-12 ( a 12 inch concentric coil). They are not made any more, and hard to find.

I have one for my CZ6a and it's a great beach and farm field coil.

 

[gleaner1]

I think the Fisher CZ-6a is a land version sort of the CZ-20. I used to wade with mine till I got the 20 as the cables are long enought for neck mounting with the CZ-6a.

cz5 is the land version of the cz20!! i have seen cz20s with the large cz coils spliced or hardwired on!!
if you want to keep your cz20 a cz20 i would not recomend trying to open the control housing at all!!!!! one misstep and you will have to send it in and have it converted into a cz21. not a bad thing but it will no longer be a cz20!!! sorta like having your 64 vette "upgraded" to a 2010 vette .

So what is the largest coil (including after market) that can be safely spliced onto the CZ-20/21 without retuning? Been trying to get this answer for quite sometime but it seems nobody is certain? Or is it just not possible? I'm guessing that since nobody seems to know for certain there's a bit more to it then just splicing the coil in.

scoop, I think fisher "recommends" aligning the boards no matter what the coil size being swapped. Bummer.....
The FZ 12 should work, its made for the cz machines. Bill Ladd did a review on it. Nasa Tom states "marginal" depth increase. If you can get 2 more inches in air using the big 12.5, I say its worth it even if you have to send the machine in for adjustment. I want to go from the factory 8 to the factory 10.5, or even put on a small coil say 5".

 

[Lowbatts]

I think the Fisher CZ-6a is a land version sort of the CZ-20. I used to wade with mine till I got the 20 as the cables are long enought for neck mounting with the CZ-6a.

cz5 is the land version of the cz20!! i have seen cz20s with the large cz coils spliced or hardwired on!!
if you want to keep your cz20 a cz20 i would not recomend trying to open the control housing at all!!!!! one misstep and you will have to send it in and have it converted into a cz21. not a bad thing but it will no longer be a cz20!!! sorta like having your 64 vette "upgraded" to a 2010 vette .

So what is the largest coil (including after market) that can be safely spliced onto the CZ-20/21 without retuning? Been trying to get this answer for quite sometime but it seems nobody is certain? Or is it just not possible? I'm guessing that since nobody seems to know for certain there's a bit more to it then just splicing the coil in.

scoop, I think fisher "recommends" aligning the boards no matter what the coil size being swapped. Bummer.....
The FZ 12 should work, its made for the cz machines. Bill Ladd did a review on it. Nasa Tom states "marginal" depth increase. If you can get 2 more inches in air using the big 12.5, I say its worth it even if you have to send the machine in for adjustment. I want to go from the factory 8 to the factory 10.5, or even put on a small coil say 5".

Just curious but I'm guessing we should be retuning our CZ panels every time we change coils? No wonder I haven't found Atlantis yet!

Just seems that if you need to recalibrate the CZ-20 board every time you change the coil, and it is the same board as on any other CZ, as I understand it, then my 10.5" would not be any advantage over my 5", or my 8" coil. Of course that's not my experience.

Having used all three OEM coils on two different CZ5's and one CZ7, there are predictable changes in operational characteristics. One or two of inches of clear depth increase do make for a definite change in recoveries.

 

[Willee]

I have done coil wire surgery on my cz20 four times. It is not difficult to tear down a cz20, it's in fact easy. But it is surgery and you have to be ready for it. Good clean work area with good lighting. You will need a philips screwdriver, a bit of soapy water... and a bit of courage. Its not bad really. When, not if, I do it again, I will do a pic spread of all the steps. The cz20 is very susceptible to coil wire fatigue. If you come across a brain dead 20, I say it is 95% chance failed coil wire.

Please do ... I would have serviced my coil wire problem if I had known how to get the cover off without damaging the detector seals.
I have changed coils many times on my White's BeachHunter ID with great success.

My CZ-20 is there now being converted to a CZ-21.
I thought all it needed was the coil wire cut back a bit and re-soldered to the board as it have become intermintent where it entered the detector housing.
They could not / would not do that without first converting it to a CZ-21.
Then they called and said the cable itself was damaged beyond repair (pin hole) and it needed a new coil that they would not have until December.
I am thinking silicone seal and RayChem shrink tubing would have fixed that.

In their defense ... they are trying to return to me a machine that will work trouble free for years to come.
They had a used coil and cable they offered to install for free.
So I am not knocking their service ... just did not understand some of their explanations of what was wrong and what they could fix.

Perhaps someday they will see the value of a waterproof coil connector and give us some coil versatility with the CZ-21.

 

[Willee]

So what is the largest coil (including after market) that can be safely spliced onto the CZ-20/21 without retuning? Been trying to get this answer for quite sometime but it seems nobody is certain? Or is it just not possible? I'm guessing that since nobody seems to know for certain there's a bit more to it then just splicing the coil in.

Yes ... there is a lot to it.
The cable is actually two coaxial cables not just some wires.
Coaxial cables have an impedance rating that is matched to the circuitry and a splice if not done properly would change that impedance rendering poorer performance.
The detectors like Tesoro and Garrett use waterproof connectors and the circuit is tuned to the characteristics of those connectors
If water gets into the connector the characteristics change resulting in degraded performance.