XP deus coil modification

[dfbowers]

The first scratches came to day, at my newly painted 7" coil.. Need to make cover or protection. But 2 hours search and 4 old hammered coins.. Its working pretty good amongst a lot of iron.
Thanks for all you help to make this coil.
Henrik

7" coil covers coming your way..
Don

[Skippy]

Yes, we want to see those hammered coins.
So, have you had enough experience to know that you got the coil size right? Do you think a smaller one would have been better? I ask because I kept trying to persuade you to 'think small', knowing how good the 5 inch DD is on the Fisher F75 / Tek T2.

I've been thinking a bit more about shielding, about the conductive plastic, about the conductive filler resin. etc. When you have the time, it would be informative if you could analyse the original coils construction. I think the outer case resistance is best measured using a long strip shape. Such as a 10mm x 50mm x (?mm thickness), measure it end-to-end. As for the filler, I guess it will be hard to cut to a precise shape. Could you make a 10mm cube, and measure Resistance from the centre of one face to the centre of the opposite face?
With these figures, it might help recreate what XP have done.
I'll post up more later.

[sinclairuser]

if you found them in the same field, they would be considered as a hoard in the uk.

[golfnut]

Show us a pic of your hammereds !! Steve

[Henrikras]

The first scratches came to day, at my newly painted 7" coil.. Need to make cover or protection. But 2 hours search and 4 old hammered coins.. Its working pretty good amongst a lot of iron.
Thanks for all you help to make this coil.
Henrik

[sinclairuser]

dons shells are exellent, nice job it seems from skippys pics xp are not worried about interwire capacitance

[Henrikras]

Skippy it was 15.9 the RX and yes the TX 10.4 - how does that effect you mathematic ?
EDIT THIS POST - Can't Remember my own work... Sorry 14.9 mH you where right. SORRY.

Finish paint and bottom seal. (Pictures)

[Skippy]

Here's some mathematics for you.
You measured inductances as: RX = 14.9 mH; TX = 10.4 mH. Ratio = 1.433, so the Turns ratio = Square-root(1.433) = 1.197
Your coil cross-sections show: RX = 155 Turns; TX = 129 Turns. Ratio = 155/129 = 1.201.
Pretty darn close. This also shows that if there are any 'extra' windings, for mysterious purposes, like broadband nulling, they can't be more than maybe 1 or 2 turns.

[Henrikras]

Your are a genius Skippy.

[Skippy]

You need to make a really good multi-frequency 9 /10 inch coil winding. Then you can sell your existing stock coil. A future idea, maybe.

Regarding your RX coil pre-amp. Here is the circuit diagram. To increase the gain, your two obvious choices are (1) decrease R1; (2) Increase R2. You have to keep the time constants R1*C1, and R2*C2 the SAME. So one obvious solution is to halve R1 (add another R in parallel with it) and double C1 (another one on top of it). R1 is likely to be 47 - 100 Ohms, C1 probably 470nF. R2 is going to be 10 - 50 times larger, I should think. Doubling gain will give +14% air-depth, roughly. With your null not being super, any more gain may possibly cause problems.

[sinclairuser]

well done, i said before once you have a working bluetooth box winding other coils is trivial as you can reuse it on your other wound coils, the only limits are materials used, so 5",6",7" or whatever you like.
a nine inch coil board may work better on the 7" coil but who knows for sure, as skippy said it may well be the gain that is different, the only limiting factor is the cost of the deus coils, even more so just to chop them up, and of course damaged/cheaper deus coils are not worth risking for your purposes as you need to unsure correct function to start with.

one thought i had was maybe its possible to open the coils without destroying them, take out the board and battery and add a cable and reseal the coil, then connect it like one of yours, that way you will still have a working deus 9" coil, i doubt that its construction is different apart from size, you know how its done why completely destroy another coil there has to be a trade off where you can have your cake and eat it.

[Henrikras]

You got it...Thats must Be why.

[Skippy]

Maybe it's to do with interference between coils? Using two identical machines near each other is a bad idea, that's one reason many micro-based machines have freq shift eg. Tek T2, so two people can operate near each other. If you have two Deus coils, you can run them independantly, can you not, one on headphones, one on the controller+wired headphones?

[Henrikras]

We still dont know why XP used different Freq. at all 3 Stock coils... 17.6 / 17.4 / 17.2 khz and lowest the Big coil, highest the 9" and the 11" in between. It could be something they had done in programming the brain at the PCB, which could Be ground coverage, or what it calls, when a bigger coil see more ground!!!

[Skippy]

Yes, but don't forget, almost every other machine out there has no idea what size coil is stuck on it, and they don't misbehave as a result. The most likely thing that is different between the different coils is the gain of the amplifier - lower for a big coil, higher for a smaller one, at a guess.