minimum detecting distance

General speaking.
We all know that being to close to other hunters affects the depth of some machines, but about what would be the minimum distance for two detectors to prevent any substantial loss in depth?
When I'm hunting within 10' of my buddies machines (Whites DFX, V3i) my Etrac requires noise chancel 2 to quieten down the machine. I all the well know that doesn't guarantee no depth loss.

Tom has discussed silent EMI before. So id also have to ask..... does just a freq shift really do much except all you to hunt if the machine is still getting silent EMI from the other machine? As far as the distance id think it machine specific before the chatter is eliminated. Thats in reverse for an Exp SE.... it would closer to channel 10 or 11. Normally i let them start their machine close to me then do noise cancel. Generally thou on the beach i use channel 11 anyway.

Dew

Guess it all depends on the units. Heck a fellow can be a football field away from me with a CZ and I will know it with my CZ. And lets not forget about silent EMI....
I know two CZ guys hunting together cause them to lose depth and stability so get a buddy that doesn't affect the unit in hand..Everyone welcome to say what unit affects their unit of choice....
PS: I just don't hunt with other CZ guys and truthfully the unit of choice of most locals is the Explorer series...

Always noise cancel the Explorer type in the group.
I can hear the Explorer or E-trac or 3030 sequencing channels through the headphones on my cz, until it settles on one, and then silence. I know it works because of testing undug targets within arms distance.

CZ's need to be about 120' apart from each other.
F75's need to be about 60' apart from each other.
A CZ and a F75 can be 19" (inches) coil-to-coil from each other before any interference is incurred.

Different detectors give different results. Audible interference is the most obvious resultant. Silent interference is the most UNobvious danger. The F75 (F70 & T2) are unique insomuch as to give/present any type of interference audibly. CZ's are just the opposite. They will incur interference........ and ............. under most circumstances.......... you will never know it........ because you will never audibly hear it; yet, they may be suffering a fairly large performance reduction.......... and you will never know it........... continue to hunt............. and possibly 'write-off' an area as 'hunted'......... due to minimum 'finds'.

Now....... with the aforementioned........... one more point is worthy of reporting. Say you have 10% EMI/white-noise/interference induced in the air.
The F75 may incur a 10% overall performance reduction. You will hear it, know it, see it, feel it.
The CZ may incur only a 2% overall performance reduction. Due to the inherent stability of the multi-freq CZ platform...... you may not hear the interference; subsequently, may never even know there is a ever-so-slight reduction in performance.

Yes.......... I reported this data before........ probably in much greater detail.......... yet, , , don't remember where. Possibly in the Rcpt Ack of F75 LTD Proto thread...... or COMPILATION #1 // COMPILATION#2 thread.

NASA-Tom Wrote:
-------------------------------------------------------
> CZ's need to be about 120' apart from each other.
> F75's need to be about 60' apart from each other.
> A CZ and a F75 can be 19" (inches) coil-to-coil
> from each other before any interference is
> incurred.
>
> Different detectors give different results.
> Audible interference is the most obvious
> resultant. Silent interference is the most
> UNobvious danger. The F75 (F70 & T2) are unique
> insomuch as to give/present any type of
> interference audibly. CZ's are just the opposite.
> They will incur interference........ and
> ............. under most circumstances..........
> you will never know it........ because you will
> never audibly hear it; yet, they may be suffering
> a fairly large performance reduction.......... and
> you will never know it........... continue to
> hunt............. and possibly 'write-off' an area
> as 'hunted'......... due to minimum 'finds'.
>
> Now....... with the aforementioned........... one
> more point is worthy of reporting. Say you have
> 10% EMI/white-noise/interference induced in the
> air.
> The F75 may incur a 10% overall performance
> reduction. You will hear it, know it, see it, feel
> it.
> The CZ may incur only a 2% overall performance
> reduction. Due to the inherent stability of the
> multi-freq CZ platform...... you may not hear the
> interference; subsequently, may never even know
> there is a ever-so-slight reduction in
> performance.
>
> Yes.......... I reported this data before........
> probably in much greater detail.......... yet, , ,
> don't remember where. Possibly in the Rcpt Ack of
> F75 LTD Proto thread...... or COMPILATION #1 //
> COMPILATION#2 thread.


"F75's need to be about 60' apart from each other."
If they are on the same frequency setting?
Tom, have you done actual in ground test to determine your % losses with the F75/CZ or are these estimated numbers?

Mark......... most are 'controlled environment' tests....... for a isolable 'variables removed' validity result. But......... keep in mind.......... I have tested very few detectors...as compared to the vast quantity of detectors available on the open market today.

NASA-Tom Wrote:
-------------------------------------------------------
> CZ's need to be about 120' apart from each other.
> F75's need to be about 60' apart from each other.
> A CZ and a F75 can be 19" (inches) coil-to-coil
> from each other before any interference is
> incurred.

NT, when I go out with a friend around our local cellar holes, I have my CZ70 and he has my CZ20. I don't recall having any problem with interference when within even 8' of each other. Is this due to one being a water machine?

They are both CZ's. The plastic case/box makes no difference. You will encounter silent performance reduction when that close.

Is the following a realistic test that can be done on site if you are concerned about degraded performance?


First do an air test in an area where there is little if any EMI or other type of interference.

Do the test outside where you can put the machine on the ground with the coil vertical to the ground.
Record basic information like a dimes and nickel's air distance.
Then when you are hunting and feel there might be performance interference "or have no idea" , do an air test and compare results.
It would be very obvious if a dime air tested at 12" then on site you could only get 8" from the coil.
Thoughts

In the ground is more realistic; yet, your intent is still valid/accurate.............. posing a good base-reference.

Spimly a CZ is a CZ and believe me after using them for 20 odd years and actually reading several factual stories if a fellow has a CZ in his hands and I have my CZ6A in mine
time to change hunting partners and yes Ozzie the noise cancel of the Explorer series indeed works if your buddies unit is interferring with yours as been there done that when
I hunted with an Explorer and several different hunting partners....