Radio Shack/Micronta 4003

[Peter Jones]

Has anyone got a circuit diagram for one of these , as they often turn up cheap at boot sales or on e-bay etc. , I know there's a reason for their low 2nd hand prices, but they must be a cheap way of experimenting ?

[Randy Seden]

Re: Radio Shack/Micronta 4003

They are the worst detector I've ever owned!!! If you want to play around with a cheap detector that's under $100, get the Hay's electronics T/R unit. Or the cheapest one I had that worked pretty good was the Alert Prospector for $39. Not a bad little unit with the only problem being that it wont work if it's over 90*F. But if you adjust the sensitivity down before it actually breaks into oscillation, it's not a bad little beginner unit. I DID buy a Micronata 4003 off of ebay just to play with and the problem with it is it's all digital and not good for more than 1" depth!!! I even replaced the couple opamp chips with ones that have hotter gain and not one whit of differance.

Oh, there is one detector that is a variation that appears to have been upgraded and its sold by Big 5 and is sold under the Coleman label. Regularly goes for $200 and they have it on sale for $99 from time to time. Now from a report of a guy on a prospectors forum is a pretty decent beginner unit that will tell you if the object is ferrous or non-ferrous. This guy used it to track the amount of black magnetic sand to locate where gold may be on a river bank. Good Luck!

Randy Seden

[Peter Jones]

Re: Radio Shack/Micronta 4003

Thanks , I am in the UK so a Hays may be difficult to get hold of. Luckily we are blessed in the uk with a couple of manufacturers of cheap detectors which work very well , however the microntas are often to be had for around £10 working , and if all else fails the hardware can be used for other projects
One of my older "project" machines is a C-Scope , British manufactured , from the 70's which cost me all of £2 ! OK it needed fixing and now needs a new control box but it works very well for a machine with only coarse/fine tune controls and no discrim.

[BJ]

Re: Radio Shack/Micronta 4003

I have one to here over at the scandinavian pond
This detector seams to go under a load of different names and different housings
(mine says made in china inside) but
still its a crap detector!! Or not?

I had examined the detector electronics a tiny bit and the design is the basic sync demod, VLF design from the 80ies, the real problem with
the detector is not the electronics, its the
search head, open it up and rewind the RX coil and put in som glue while you wind it and
let harden, then you will have a stable RX coil, then glue the TX coil and let harden. Now
aling the search head so the picture on the scope gives a dip in the recieve signal or
dissaper (cant remember wich) then glue the
RX coil to this calibrated position.

Now, fill up the entire search head with som epoxi or any other plastic solution that
hardens into a "non movable mass" and the detector will perform a lot better!

No, i dont have the schemos!

The one i bought new costed 80usd (translated)
and was absolutely terrible until modified.

Reg
BJ

[Piotr]

I have the diagram

I can send it via email to anyone interested.

Piotr

[erol]

Re: I have the diagram

Hello
I need micronta circuit diagram for repairement.
Ýf you can sent it to my e-mail adress I will be glad. Do you know howcan ý increase capacity of micronta 4003
Thank you.
Erol Ünal

[email protected]

[Boris]

Wanted circuit diagram for the Micronta 4003

Hi there

Im looking for a circuit diagram for a Radio shack
Micronta 4003

Regards
Boris

[Unregistered]

4003 schematic

I can send it via email to anyone interested.

Piotr

PLS SEND TO [email protected]

[Qiaozhi]

Here it is ->

[montepollock]

4003

I had a 4003 some years ago and found a Ben Franklin Half dollar at 6",but later(c1990) with an Whites Eagle2 on the same site found an Indian Head Pennie at 9".
Not a scientific test but would probably be consistant.
Since then I have found coins that have more than paid for more detectors.
Happy Hunting,Mont

[Qiaozhi]

I had a 4003 some years ago and found a Ben Franklin Half dollar at 6",but later(c1990) with an Whites Eagle2 on the same site found an Indian Head Pennie at 9".
Not a scientific test but would probably be consistant.

I'm not surprised.
The Micronta is (to put it bluntly) crap. This is definitely a case of "you get what you pay for". Essentially it's a child's toy.

[Unregistered]

Micronta 4003 RX rewind

Hi I know this is an old thread, but I wondered when you rewind the RX coil do you just rewind it to the original spec (i.e same gauge wire and same number of turns) or do use a different spec. Just wondered rewinding it helps.

Any help would be great.

Thanks

HS

I have one to here over at the scandinavian pond
This detector seams to go under a load of different names and different housings
(mine says made in china inside) but
still its a crap detector!! Or not?

I had examined the detector electronics a tiny bit and the design is the basic sync demod, VLF design from the 80ies, the real problem with
the detector is not the electronics, its the
search head, open it up and rewind the RX coil and put in som glue while you wind it and
let harden, then you will have a stable RX coil, then glue the TX coil and let harden. Now
aling the search head so the picture on the scope gives a dip in the recieve signal or
dissaper (cant remember wich) then glue the
RX coil to this calibrated position.

Now, fill up the entire search head with som epoxi or any other plastic solution that
hardens into a "non movable mass" and the detector will perform a lot better!

No, i dont have the schemos!

The one i bought new costed 80usd (translated)
and was absolutely terrible until modified.

Reg
BJ