Coil readings

[Mark-VA]

I had a Minelab Etrac until recently and sold it to a fellow hunter.
I kept the 6" Excellerator coil.
The 6" coil has the identical pin configurations as my Fisher F75.
What can a person check to see if these are interchangable with each other.
Can you take ohm reading of each and see it they could be used.
I want to try it on my F75 detector.

[Carl-NC]

Generally coils are not interchangeable across brands, and often not even within a brand. Even if you get the pinout corrected and manage to make it run, the target responses (VDIs & tones) will be way off.

[Mark-VA]

Advise taken, I'll just sell the coil. Better that than mess the detector or coil up.

[Mark-VA]

Can I assume that after a coil is designed and made then there comes the software changes to make them work correctly?

Generally coils are not interchangeable across brands, and often not even within a brand. Even if you get the pinout corrected and manage to make it run, the target responses (VDIs & tones) will be way off.

[Carl-NC]

The coil is usually tightly tied to the hardware design. Most micro-based detectors do final calibration in software, but if you try to apply a completely wrong coil then calibration is highly unlikely.

[Henrikras]

Dear Mark and Carl.
Thanks fore Very Good information in this thread. It help't me a lot, in my ask fore help in Another thread. (Difficult to mix coils )
But please Carl... If you got a cold microphone cable problem, and you can't find Another coil brand, what would you do?
The Russian way, and open the coil and change the cable ? Or build you own coil ?
Please help me...
Henrik from DK.

[Mark-VA]

I had to do a little playing last night and here are the results of ohm settings of these three coils.
Strange that two different companies 1000+ miles apart would use the same type connector with the exact pin usage.


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Would it hurt to attach the Minelab coil to a F75 and see what happens.
Could it hurt the machine in any way?

[Henrikras]

Dear Mark... I am NOT an Expert, but I can see that the Transmitter and the reciever coils are 180 degree exchanged at the plugs.
So don't try... The resistor value is allso to must diffents to I would try... Last! the minelab useing FSB (multi frequency) and the F75 single (13 khz), so even that says me, that it won't work. But I'am no expert to say this matter fore sure.
Trying out something Electronics with some Higher resistor normaly don't hurt, but in your case, I would Be Very carefull.
(Ps. My SEF coil 30x38 to mine F75 got the same ohm as yours 11" coil)
Henrik.

[Mark-VA]

Thanks for the heads up.
This whole subject is very intriguing, actually to the point of wanting to have more knowledge of the matter.
I have tested a lot of different detectors over the years and never knew some of the basic/complex workings of the machine in general. I'm a believer, the more you know of any subject the better you can become. I'm always striving to become a better more knowledgable detectorist.
Actually, my hunting buddy uses the V3i and it has held my interest since the day he got it.

[Carl-NC]

Minelab has TX on 1-2, Fisher has TX on 3-4. You can certainly try it as-is, at your own risk of course. If you're really good, you can re-wire the Minelab coil and possibly figure out what changes to make to the F75 to get it to work decently. But then your Fisher coil won't work.

What you're wanting to do is bolt a Chevy transmission up to a Ford engine. People have done that, but it generally ain't worth the trouble.

[Mark-VA]

Thanks for the facts Carl.
To many variables for me to try and the risk is to high.
I'll just sell the coil since I don't have the Etrac anymore.
Still very interesting to say the least.

This is a main reason I like this forum.
If you have a question it will be answered.
Then you walk away knowing something new.

[Mark-VA]

I found this in the back of my detector manual.
"This device has been designed to operate with the antennas listed below and have a maxium gain of 3dB. Antennas not included in this list or having a gain greater than 3dB are strickly prohibited for use with this device. The required antenna impedance is 53 ohms."

I hate to be stupid, but what does all this mean?

[Carl-NC]

All it means is, "If you stick a non-compatible loop on this detector, you void the warranty."

[Mark-VA]

That is plain and to the point, thanks Carl.