Nexus Coil Design

[JC1]

Actually

Hi Tinkerer,

Actually I am more interested in the Nexus design for

the fact of nonmotion then I am on the stupid reasonant

coil routine. Just to see how he handled it. Now understand

on most, by the final stage being AC coupled they are able

to get that last bit of gain 2-10 out of the detector. so if

you just get rid of it, you got a less sensitive detector, which

is no fun, considering how insensitive they most are anyway,

but if done right and somekind of "final" dc restoration is done

then this is "nice". But hey just curious, sure I will not be getting

any schematic. and I don't even blame him, even if the real Georgi

did say it, which i guess he did not. Still it is nice to see

nonmotion, especially if it is close to the sensitivity of the "best".

In fact I would give up sensitivity somewhat to have nonmotion,

and in fact I put a switch so I can change between motion and

non motion on mine. Also can adjust gain higher/lower so can get on

top of a possible target and crank it up to see if it looks good, or

turn back down some and go back to searching.

[Qiaozhi]

Hi Tinkerer,

Actually I am more interested in the Nexus design for

the fact of nonmotion then I am on the stupid reasonant

coil routine. Just to see how he handled it. Now understand

on most, by the final stage being AC coupled they are able

to get that last bit of gain 2-10 out of the detector. so if

you just get rid of it, you got a less sensitive detector, which

is no fun, considering how insensitive they most are anyway,

but if done right and somekind of "final" dc restoration is done

then this is "nice". But hey just curious, sure I will not be getting

any schematic. and I don't even blame him, even if the real Georgi

did say it, which i guess he did not. Still it is nice to see

nonmotion, especially if it is close to the sensitivity of the "best".

In fact I would give up sensitivity somewhat to have nonmotion,

and in fact I put a switch so I can change between motion and

non motion on mine. Also can adjust gain higher/lower so can get on

top of a possible target and crank it up to see if it looks good, or

turn back down some and go back to searching.

Hi JC1,

I don't really want to be the one to crush your excitement about the Nexus - BUT - this is not a nonmotion detector in the same way you're expecting. Yes - I know it says "... non motion type of detector with fast auto tune ..." but it still requires the coil to be in motion. You cannot hover over the target, otherwise the signal disappears. The auto tune is "fast", as it says on the Nexus website.

By the way, contact Georgi if you don't believe me.
http://www.nexusdetectors.com/Contactus.html

[JC1]

I believe you

Hi Qiaozhi,

Thanks for the input.

I believe you. In fact that is what I would expect.

Just wanted to see if I was wrong.

Too bad. Lot of trouble to get the nonmotion working well.

Lots of extra parts, expense, etc. But sure is nice.

At least I like it, everybody that has tried it goes Wow!

I determined years ago that I had to do it, and did.

[Qiaozhi]

Hi Qiaozhi,

Thanks for the input.

I believe you. In fact that is what I would expect.

Just wanted to see if I was wrong.

Too bad. Lot of trouble to get the nonmotion working well.

Lots of extra parts, expense, etc. But sure is nice.

At least I like it, everybody that has tried it goes Wow!

I determined years ago that I had to do it, and did.

Yes - non-motion can be really nice to use. It's just the drift problem that is a pain. Are you saying that you have designed your own non-motion detector? If so, how do you find discrimination compares to a motion detector. Theoretically it should be better, as you can hover over the target and get a consistent reading.

[JC1]

Better

Yes, I design my own from front to back.

Nonmotion--Everything is better. Vlf or PI.

Vlf--still can AC couple before demod, get as much gain

as possible before demod, then low drift design and

dc restoration {this is the trick}{big secret}

PI--get as much gain as possible, only allow rec signal

through without flyback etc. before sampling {provides

first dc restoration}, then low drift design and dc restoration.

I use alot of modern High quality analog switches for various

things. Some Drift is there and somewhat bothersome at highest gain

but not bad. and not as bad as being stuck with motion.

It makes you pay attention to every fine detail, almost any

change in anything results in a drift. for example the sample pulses

must be exactly the same width (or at least not change) or you

will get drift from this. But it is not really that hard to do but not

what you would want to start selling to the general public.

[Unregistered]

Nexus alert

Nexus on ebay at the moment (Ebay UK )

[Unregistered]

Nexus Link

http://cgi.ebay.co.uk/ws/eBayISAPI.d...MEWA:IT&ih=009