XP deus coil modification

[Henrikras]

Yes yes Skippy... But this issue that the PCB thinks its a Big coil, still is a open quenstretion.

[Skippy]

But...but.. you have a plug and socket on this circuit board, so you can make as many different coils as you like? Like another small one, or a REALLY BIGFOOT, or a Two-Box set-up. (That's one of my projects for my F75, a two-box.)

[Henrikras]

Skippy I will look after a secondhand 9" coil and use this to the next project like a 5-6" coil.... This Bigfoot costed 120 £ and Maybee a 9" can Be found at the same prize.. That would allso give me the chance to test this 7" coil with the 9" PCB, plus find out how the 9" is made...
Henrik

[Skippy]

Sounds like a good result, Henrik. I'll watch the videos tomorrow.
Are you going to try a proper small coil, like 5 inches?
I still think there is some gain changes worth trying on the circuit-board. With this PCB being designed for a large coil, it possibly has a lower amplifier gain to match.

[Henrikras]

Hi all...
Couldn't dare to go out with the 7" at one of my hot spot... What a nice day. The 7" coil allmust worked perfect.
There is still some small breaks up in the signals, not much and some are from reel iron, and some from the coil mixing the ground effect with the good signal. But 95% perfect I would say.
The best of all, I found a small hammered cobber coin from 1422, second signal with the 7" coil.
The first good signal I got, was recorded. It was One thinny little piece af a bronze ring. (I wonder how small Gold this coil can find?)
This is the Utube; http://www.youtube.com/watch?v=Vk7Dg-OcnGc&sns=em

This is the video where I found the little cobbercoin, think 3-4" down.. Not bad. Made my day.
http://www.youtube.com/watch?v=2u6q3ukh7fs&sns=em

I did a test Shortly after the coin was found, to find out how it would compair with the 9" coil. Not bad either.
This is the utube. http://www.youtube.com/watch?v=gXc4bBDbY5M&sns=em

Then I made a test with a iron nail ( the field is filled with those kind ). This test allso gave the 7" coil a winner role, but but
not by much. This is the utube. http://www.youtube.com/watch?v=hA-ieB3VoEY&sns=em


Dear Friends. Without your help, this project couldn't had Be made. One Million THANKS.
Now the finish paint and make it nice and usefull, then maybee the last try with 1.0 nf capacity, with a hope some small extra clearness can Be found in the signals... We did it, a new World record, 7" Deus coil in 3-4 weeks.
Henrik.

[Henrikras]

Muddy. He will properly lose some performance. Dont know but 15 NF is a Big one.
Gulfnut - could Be a problem I hadn't notice, if the Graphite touch to the grass. Thanks.

[muddy fingers]

It is a 15nF capacitor that is being used in the resonant circuit of the transmitting coil. (In the You Tube video mentioned above)

[golfnut]

You mentioned the machine was playing a partial Iron tone for your target - this should likely be a phasing thing? you could try a 1nF across the Rx plug connection to throw the phasing a little and retest. Or across the Tx - like a fine tune and retest

A lot of designs do not let any graphite to touch the ground - as you get a discharge and current flow and voltage changes on your coil - can false ..

Could try this with a plastic bag taped over coil to simulate having no graphite on your surface.


I think your coil may need this and you may do it with a coil cover! Don may make you a mirror part!!

Beyond this, you may be looking at the limitations of your cable - I am unclear on the suitability of you cable.


Anyway - you took on a huge challenge/risk/ investment and its looking good.



I really think you have done an ace job here, in record time.

I feel you are teaching us now. We never used to have a drain above and below and we never had sheild resistance this low, and we all suffer chatter on wet grass - so we need to try some of your work out.

I cannot fault your enthusiasm and dedication to you project - Steve

[muddy fingers]

Hi Henrik, Have you seen this video on You Tube? It shows a way of quickly altering the frequency of the coil so as to cut out EMI http://youtu.be/dmIcE_CHBt4

[Henrikras]

A lot to think through.
just been out this morning, with more graphite (outside) - down to 3-600 ohm. Still better, close to acceptabel and a proper test at a field. This idea came up (not me, but from a helping hand) - an idea to find out the how the shielding perform . Link. http://amasci.com/emotor/chargdet.html
I need to ordre this mosfet MPF102, could Be a funny little project.
ps. It seem that the highest 11 khz Freq (11.655) is the best !! Difficult to say 100% but a feeling! which could Be right.
Henrik.

[sinclairuser]

apart from a quick swing in my mates back yard i have have not used a deus, can you tell/program the deus to run at a single frequency?.
if you can pick the one closest to the resonance of the coil and program it in, then tune the coil using caps in your battery box try to get it running at as close as the deus expects, then try the coil and see if any of the symptoms persist.
this may not be possible i dont know, but if it is it will tell you if frequency is an issue.
i have a hunch that the circuit boards fitted in deus coils are all the same, maybe different caps are used on the boards but i bet thats it no more, the coils may well be different sizes, but xp will use as many common parts as they can.
as skippy said you made your coil as close to the specs as you could, that should not be an issue, unless the deus is smarter than we think and knows what size coil is connected to it, if that is the case, it could be over or under compensating.
it maybe that in order to run a 7" coil it will have to run at a single fixed frequency, but like i said can the deus do that?.

[Skippy]

?? But you made the small coil so that it matched the specification of the BIG coil, so the fact that it runs at different frequencies (I don't know why?) to the stock 9 inch one is not important.
I wonder if there are more secrets we can find out from the dismembered big coil.?

Maybe it would be an idea to keep the coil away from the graphite paint? Eg. paint the inside of the coil case, add 5mm of resin. insert the coils. Add more resin, covering it 5mm. Paint with graphite. Seal up with resin. Just an idea...
Here is the datasheet for the Graphit 33 spray:
http://www.farnell.com/datasheets/318264.pdf
The surface resistivity of 1 - 2 K Ohms / square seems about right.

[Henrikras]

Yeah Gulfnut . I got that, and made allso a lay outside the Shell. Just to copy the conductive plastic.
Only thing I can see helps.. With those Strange interference making the signals Breaking up like iron close by, is more graphite and lower resistance. But I'll let it Dry up some more.. and take a day off the project, until saturday.
Thanks anyhow.
Henrik

[golfnut]

If you have this, Im running out of ideas to help you


Phone Alain at XP and explain truthfully what you are trying to do do for your project/requirement.

He may help you

[Henrikras]

Here a reason this project never will work.
Just been playing with the 9" Stock coil.. Freq. is; 17.730-17.606-17473 and 11.820-11.655-11.494.
This Bigfoot coil (PCB) which is my 7" coil Freq. Is; 17.361-17.241-17.123 and 11.655-11.494-11.338.

It tells me, that I should HAD found a second hand 9" coil, and started with that, NOT the Big foot coil. (Shi.....ttt).
That allso telling me, Thats why the resonans at the TX was so sensitive.. 1 turn a Big different.

Saturday will Be the judgments day.

Take care.

Henrik.