XP deus coil modification

[Skippy]

I'll try first.
Is your Li cell fully charged? I'm sure it is, but...

I don't think your graphite paint resistance is too high, it should be fine. It matches what George Payne says ( I will find the link).

Is your short cable fixed? I know it's short, but there are cases of 'noisy' cable, that have microphony, (the Blisstool had this, I think?).

Is there any accidental connection between the shield/paint and any of the 4 main wires? I don't know how you can measure this, unless you can disconnect the shield wire from the RX negative. Just use a ohm meter.

Am I correct in saying that on this build, you don't have a seperate shield around the RX, to isolate it from the TX?

One unknown, I mentioned early in the thread is: The Deus thinks it has a BIG coil on it, not a small one, so it may be doing something different because of this. Such as different time-constants in filters, or different gain/sensitivity settings. I can't think why this would cause problems. If anything, I would expect sensitivity to be lower.

How rigid do you think your coil is? Does swinging it away from the ground (like 60cm away) cause problems? The amount of signal change from the coil needed to trigger the machine is TINY. That 15 mV pk-pk needs to change just 10 microvolts (maybe less) and it will signal. Do you get false signals if you 'pump' the coil up and down ( way away from the ground, > 1metre) .

Does the null still read 15mV out in the open? Drag your scope outside and see.

[Henrikras]

Thanks Skippy... That some good ideas to work with.

This quenstretion : Am I correct in saying that on this build, you don't have a seperate shield around the RX, to isolate it from the TX?
NO - the RX and the TX are not seperated !!! That would had been the third shield type, wouldn't it !

I will go to the lab now and try something - to come closer to something usefull.

Henrik.

[Skippy]

Here is the George Payne article where he talks about coil shielding (at the end):
http://jb-ms.com/Baron/gb.htm

[Henrikras]

Thank you Once more.... Just been out - painted more graphite and down to 400-600 ohm, but still spots with 1.0-1.5 Kohm..
THAT gave a Big different in the right direction. Close to the goal now.

Sorry about this bad quality video. just recorded it outside with the phone. Hope you can hear that the signals are more clear.
link: http://www.youtube.com/watch?v=Sfr3V6KGFBI&sns=em

This is the video Shortly after, measuring the graphite resistance... Pretty low I would say.
Link: http://www.youtube.com/watch?v=hlzQZp1xv0E&sns=em

Henrik

[golfnut]

Hi,

Slow it up a bit like Skippy said - as the coils are not totally potted they will move in a fast sweep and false.

You have not finished the Graphite BOX shape on 4 sides of the coil bundle - So the gound is Visible to the coil - only this now... |_|

When 4 sided conductive box you will mirror XP original - they also had drain wire where you have currently no screen. ( the drain wire requires good connection to the graphite/carbon.


Would you BOB the coil over clean earth to see if the autp ground balance is functioning correctly..

In Lab, does it reject Ferrite effectively - I didnt see in test results?

Steve

[Henrikras]

HERE IS SOME ANSWERS

I'll try first.
Is your Li cell fully charged? I'm sure it is, but... YES - CLOSE TO 100%


I don't think your graphite paint resistance is too high, it should be fine. It matches what George Payne says ( I will find the link).


Is your short cable fixed? I know it's short, but there are cases of 'noisy' cable, that have microphony, (the Blisstool had this, I think?).
NO THIS IS NOT A PROBLEM


Is there any accidental connection between the shield/paint and any of the 4 main wires? I don't know how you can measure this, unless you can disconnect the shield wire from the RX negative. Just use a ohm meter.
I HAVE CAREFULL TO KEEP A DISTANCE.


Am I correct in saying that on this build, you don't have a seperate shield around the RX, to isolate it from the TX?
NO - LIKE ANSWERED EARLYER


One unknown, I mentioned early in the thread is: The Deus thinks it has a BIG coil on it, not a small one, so it may be doing something different because of this. Such as different time-constants in filters, or different gain/sensitivity settings. I can't think why this would cause problems. If anything, I would expect sensitivity to be lower.
THIS COULD BE THE PROBLEM TO GET THE LAST 5-10% STILL MISSING.


How rigid do you think your coil is? VERY RIGID? Does swinging it away from the ground (like 60cm away) cause problems? NO
The amount of signal change from the coil needed to trigger the machine is TINY. That 15 mV pk-pk needs to change just 10 microvolts (maybe less) and it will signal. Do you get false signals if you 'pump' the coil up and down ( way away from the ground, > 1metre) .
NO FALSE SIGNALS - THE CABLE ALLSO STRIPSED.


Does the null still read 15mV out in the open? Drag your scope outside and see. THAT WILL BE IN DAYLIGHT.

[Henrikras]

Hi,

Slow it up a bit like Skippy said - as the coils are not totally potted they will move in a fast sweep and false.

You have not finished the Graphite BOX shape on 4 sides of the coil bundle - So the gound is Visible to the coil - only this now... |_|

When 4 sided conductive box you will mirror XP original - they also had drain wire where you have currently no screen. ( the drain wire requires good connection to the graphite/carbon.


Would you BOB the coil over clean earth to see if the autp ground balance is functioning correctly..

In Lab, does it reject Ferrite effectively - I didnt see in test results?

Steve

Dear Steve...

Okay I will find 2 gear and take it easy a little... You and Skippy could Be right about ist only 24-36 hours ago ist Potted.
But please- could you explain this Once more please... "Not finished the graphite box shape.........???????"

The GB is working perfectly... (Seem to so fare) - try tracking and manuel, it looks to stay calm. !!! The pump isn't good at the Deus, so that will never help us.

Its Maybee a good idea to wait until saturday with more work... A kind of panic from my side..

Thanks.

Henrik.

[golfnut]

In some of your photos I could see a thin Black line in the potting.

This is additional graphite layer - The layer had a drain wire. So the original coil bundle had graphite on 4 sides like screen box.

It also had a drain wire above and a drain wire below coil bundle.

[Henrikras]

In some of your photos I could see a thin Black line in the potting.

This is additional graphite layer - The layer had a drain wire. So the original coil bundle had graphite on 4 sides like screen box.

It also had a drain wire above and a drain wire below coil bundle.[ATTACH]29031[/ATTACH]

BUT Gulfnut - I made all that, just like the Deus coil....

[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.

[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]

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

[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.

[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?.

[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.