Is the Radiometer Ferret the best IB circuit I can find?

[BG]

Hi all:

I'd like to ask a question, hope this doesn't sound too dumb, but... I've been looking around for a detector circuit to build. Most folks seem to like PI circuits, but I was more interested in IB designs... I'm not after maximum depth, and I hunt in some really trashy areas, so some kind of discrimination is essential.

Anyway, so far the best that I can find is the Radiometer Ferret. It seems to be the only IB design I can find with any discrimination and decent depth, claimed at 8-10" (My BH LandStar can only go to about 5" in air tests. No way can I afford a second detector, though I really like Tesoros analog-type approach. As small as their housings are, I wouldn't think there would be TOO much to their circuitry, though it could be surface-mounted stuff)

Trouble is that the R-Ferret circuit was designed in the late seventies. Is there anything out there that might be more recent? Or better? I don't see any on this site, except maybe the Magnum... and that one seems pretty complex. (Designing my own is COMPLETELY out of the question... I know only the most basic of fundamentals, and couldn't design my way out of a wet paper bag)

Thanks very much
BG

[Randy Seden]

Re: Is the Radiometer Ferret the best IB circuit I can find?

BG I have good news for you. Go to the below link to Don Lancasters Hardware Hacker collection VOl. III. This is a pdf collection of the Jan. 90-Dec. 91 issues. Go to the March 1990 issue and on page 27.4 you will see in fig.4 one of the simplest detectors on the face of the planet that offers discrimination. In the article it points out that you can add a 90 degree phase network to verify junk, but as it is, it will ignore most junk. I plan on building this myself because of the sophistication this LVDT IC chip gives you in one package-amazing! Enjoy.

Randy Seden



Don Lancasters Hardware Hacker Vol. III

[Chester Park]

Re: Is the Radiometer Ferret the best IB circuit I can find?

Hi,

If you do a good adjustment, the Magnum is a good IB circuit. See this circuit in the detector section of this pages. High quality components on transmiter stage, like resistors, capacitors (1-2%, minimun 200 v), etc., is important for a good performance.

[BG]

Re: Is the Radiometer Ferret the best IB circuit I can find... THANKS for your input!

Chester/Randy/Carl:

Thanks very much for your help. I'll take a closer look at the Magnum, though I'm a little intimidated by the complexity... Don Landcaster's circuit is certainly appealing, but I'd have to do A LOT of trial& error to get the search head right, though it certainly seems simple enough. Maybe I should just build all three...

Anyway, I appreciate your help. I'll let you know how it turns out

Best, BG

[Sean Goddard]

Re: Is the Radiometer Ferret the best IB circuit I can find... THANKS for your input!

Stick around guys,

I'm planning to release a design which uses READY MADE Tesoro Searchheads, and has FULL motion operation, with tone ID and Manual/ Fixed Ground balance. I might EVEN add microprocessor control with notch discrim, and median filtering to make the discriminate more accurate (if I can find the time).

I hope to offer this as a kit, or as a fully built detector. Should be ready in about three months (I hope).

[Peter Jones]

Re: kit

How about a "modular" upgradeable kit , a basic good detector , with a second pcb available with "pro" options?
If it's only 3 months away you're probably just "polishing off" the design , but maybe a thought for the future or anyone else ?
I think there will be a market for your kit or complete detector , Red Heat have proved how good small scale manufactured detectors can be and I have not seen any worthwhile kits for usable detectors.

You could be onto a winner !

[BG]

Re: kit? Great!

Thanks for the note. Please let me know when it becomes available... if you sell a
kit, you'll be in a unique position. Personally, I'd be more interested in a
NON-microprocessor circuit, (don't like my landstar too much... too unstable, tons of false signals, and the depth calculations are totally unreliable, etc) but I'd bet most folks would think otherwise.

I'd be much more inclined to try to build a kit vs trying to prototype a circuit myself. I'm not much of an electronics expert, and can only debug a circuit with pretty detailed help. I love messing around with this kind of thing, though.

Also, would Bounty Hunter searcheads be a possibility? They're half the cost of tesoro,
don't know if they perform better. Being able to make your own searcheads as
an option would be nice. Of course, Tesoro searcheads are sometimes available on ebay for a little less.

Best
BG

[Esteban Cabrera Grinok]

Re: Nuova Elettronica

Hi

I build a motion metal detector by Nuova Elettronica (Italy). This detector works under the principle of variable reluctance. Exist other model by Nuova Elettronica with "memory of terrain".

[BG]

Re: Nuova Elettronica

Hi Esteban:

Thanks for the note...Do you have any additional information about this detector?

Thanks
BG

[massimo]

Re: Nuova Elettronica

I have the schematic and detail for the head of this motion circuit.It works nice but have a little termal drift. It is simple to assemble.
P.S. sorry for my terrible english

[massimo]

Re: Nuova Elettronica

It's a very simple design whitout any sort of discrimination is an amplitude shift detector it can detect a copper coin of 23mm at 18-20 cm in air.
I think i have same problem with E-mail because i can receive but i cant send messagge!!!!!

[Sean Goddard]

Re: kit

Hi all,

The "modular" bit is the part I'm working on now. You seem to have second guessed me!

I'm just working out what bits to leave in, and what to take out for the basic model.

I also have to do final proving with some other makes of search heads (Whites) which are VERY cheap compared to most.

I've got quite a bit to do yet, but as far as a finished design goes, it's mostly all there.

I don't have much time to devote to it at the moment, but in two or three weeks I'll be on it full time.

Also I have to make sure Tesoro don't have any reason to start legal action, after all, it IS BASED on their design, although VERY LOOSELY.

I'm planning a kit which people could "play" with and perhaps learn more about beeper technology. That way maybe some one will come up with a whole load of new ideas, and we'll ALL benefit from it.

[Peter Jones]

Re: kit

Hi , Sean.
Good luck with this project , I'd be interested in any progress reports you may post on here.
I totally agree with your thoughts on people delving into the design to find out how things work and how each aspect of the design affects the performance. It should encourage individuals (and companies) to come up with designs with better depth , sensitivity and stability than detectors available now.