Coil Internal schematic

[Wiltran]

Has anyone ever opened a musketeer coil or later whites coil to see how they were made? I for one would like to see why they chose 1 MH for TX and 14 MH for RX. Anybody have an internal schematic and any info? thanks

[John in NC]

Usually the coil is just and extension of the electronics in the box. A coil will have a certain inductance, resistance, and capacitance to match the internal electronics. If you want to build a coil, then you have to match these values. If you just want to know why those values, it's because it was the designers choice. Hope this helps.

[Carl-NC]

Not sure about the Musketeer, but White's are 0.5mH and 13.5mH. Have no idea why those values were chosen, the people who picked those values are long gone. Generally you would choose the TXL for reasonable power consumption or reasonable tank capacitance at the frequency(s) you want. The conventional wisdom (as far as I can tell) is to run the RXL as high as possible with good phase repeatability, for higher transformer gain. I question this.

In most cases, there is no matching with the electronics... you could run whatever inductance you want. Ferinstance, I built a coil for a White's V3 that has RXL = 0.5mH (instead of 13.5mH). Once the V3 was calibrated for the new coil, it ran just fine.

[ivconic]

Has anyone ever opened a musketeer coil or later whites coil to see how they were made? I for one would like to see why they chose 1 MH for TX and 14 MH for RX. Anybody have an internal schematic and any info? thanks

I did few times,
nothing special inside, just TX and RX coils, "D" shaped and wired with 2 separate coaxial.
Shield is made by use of graphite powder mixed with some "plastic" joint filler, epoxy ...similar.
Shield is electronically connected to TX coaxial litz.
Coils is simple - but effective.

[ivconic]

Not sure about the Musketeer, but White's are 0.5mH and 13.5mH. Have no idea why those values were chosen, the people who picked those values are long gone. Generally you would choose the TXL for reasonable power consumption or reasonable tank capacitance at the frequency(s) you want. The conventional wisdom (as far as I can tell) is to run the RXL as high as possible with good phase repeatability, for higher transformer gain. I question this.

In most cases, there is no matching with the electronics... you could run whatever inductance you want. Ferinstance, I built a coil for a White's V3 that has RXL = 0.5mH (instead of 13.5mH). Once the V3 was calibrated for the new coil, it ran just fine.

Once the V3 calibrated for such coil - is it remains also "calibrated" for conventional coils that usually came with detector?
Or it is than settled to work good with such coil only?
I am asking this because am not familiar much with V3 and what kind of "calibration" you may talk about.
But i bet such info may start new V3 coil ideas here on forum.
Also noticed that DFX and V3 coils could be interchangeable up to some level.
Some of those for DFX will work nice with V3 and some of those will not perform so good.
For example; Excellerator coil, 32x25cm, previously used with DFX - is performing also very good with V3 ... may say even much better than original V3 coil which came with detector.
Yet there is one smaller DFX coil (i believe it was 25cm..some..) that is not performing so good with V3..
...
If "calibrating" means "monkeying" inside the box, "turning trimmers" and similar - than i wouldn't suggest the same to others.
But if "calibrating" is something that man can do through menus - than it would be nice info, interesting for all of us here.
Any detailed info would be appreciated!
...
Carl you dropped "itchy" bone here...!

[Wiltran]

Thanks Carl and others for good info. I was not aware that coils could be adaptable for another machine.

[John in NC]

I'm like you IVCONIC. I don't understand Carl's statement when he said,
"""In most cases, there is no matching with the electronics... you could run whatever inductance you want."""

If there is no matching with electronics, then every coil would fit every machine??? Since the V3 had to be "calibrated" to work with the new coil... I think that means tuning the electronics to work with it, and I very seriously doubt that it will now work with the original coil without "re-calibrating" the electronics. JMHO

[Carl-NC]

Many detectors have actively driven TX coils instead of using tank oscillators, so they are fairly tolerant of inductance. Most detectors run the RX coil into an opamp so, again, inductance is not a big deal. However, inductance (and resistance and capacitance) may be a Big Deal for the phase calibration which affects GB and TID. So you can't just slap any old coil on a detector and go hunting. But more often than not, you can make a coil work if you know how to calibrate for it.

V3 uses a digital calibration which requires particular reference devices to make it work, so I won't divulge that info. So far, one customer has managed to find the cal menu and even though it said, "WARNING: This will completely mess up your detector. Are you sure you want to do this?" he did it anyways, and then was angry that it completely messed up his detector.

True, once you calibrate for a funky coil, the original coils will no longer work.

[ivconic]

".. "WARNING: This will completely mess up your detector. Are you sure you want to do this?".."

That message is only for SMART people, who will obey. Not my kind!
The other day i completely messed up my.... car , not detector!
Instead paying $2 for bad part - now i will pay $100 !

So, SMART devices are only for SMART people... not for DIY'ers!

P.S.
There is idea for patent that i can sell to Audi;
Audi should implement huge and hard mitt inside,
so once some "smart" DIY'er tries to be smarter than he is - that mitt to spring out and punch him directly into nose!
That's the only way to save money and "device" !

[Carl-NC]

Yes, and most devices say: "Warning: Do not open. No user-serviceable parts inside." Which is true for most users, but not for me! Yes, every now & then I also make things worse, but if you never make mistakes you never learn. You just learned something, and it only cost you a measly $100!

[andreyika]

Hi all. I would like to make a new coil for my V3. Could you show me a diagram coil? Thank you.