VLF-Micronta

[Alexismex]

Here is a schematic diagram for the Micronta :

[ivconic]

Here is pcb for that Micronta!

[Katxoto]

How do you build the coil? I don't know what use type wire & size & turn wire.
Thank you.

[ivconic]

How do you build the coil? I don't know what use type wire & size & turn wire.
Thank you.

To late for answer maybe... searching back some posts i found this unanswered question.
Well... coil for this Micronta is exactly the same as coil for Magnum.
Coil for Magnum was explained here:

http://www.geotech1.com/cgi-bin/page...gnum/index.dat

[pebe]

Just thought I would point out a couple of errors in the circuit.

1. There should be no connection between IC3a pin13 and the V+ supply rail.
2. R26 should be connected between pins 8 and 13, not between pins 10 and 14.

[ivconic]

Just thought I would point out a couple of errors in the circuit.

1. There should be no connection between IC3a pin13 and the V+ supply rail.
2. R26 should be connected between pins 8 and 13, not between pins 10 and 14.

On pcb or on schematic?

[pebe]

It's the schematic that's wrong. It didn't look right as drawn, so I got the correction from tracing out the PCB tracks.

[ivconic]

It's the schematic that's wrong. It didn't look right as drawn, so I got the correction from tracing out the PCB tracks.

Cool!
I am right now in process of tracing MD3007 pcb. Tough and complicated (because pcb was drawn originally by some maniac - so bad it is), so i am using Micronta4003 and Magnum schematics also, to compare.
Infos you gave here are of great value to me!
Thanks!

[pebe]

Cool!
.....Infos you gave here are of great value to me!
Thanks!

I'm glad to be of help.

I've bought a 4003 recently to experiment with but the sensitivity is poor. I'm going through the circuitry trying to understand the design. If I can come up with any improvements, I'll post them.

[ivconic]

I'm glad to be of help.

I've bought a 4003 recently to experiment with but the sensitivity is poor. I'm going through the circuitry trying to understand the design. If I can come up with any improvements, I'll post them.

What type of coil you have? Omega? If so that you can achieve more sensitivity with diffrent type of coil. Try to make DD coil for it. Measure inductances and resistances of present coil and use those datas to make DD coil. I was thinking to do the same in future. But first i will make another copy of MD3007 (basically it is Micronta 4003 with improved audio) and than i will experiment with coils.

[pebe]

What type of coil you have? Omega? If so that you can achieve more sensitivity with diffrent type of coil. Try to make DD coil for it. Measure inductances and resistances of present coil and use those datas to make DD coil. I was thinking to do the same in future. But first i will make another copy of MD3007 (basically it is Micronta 4003 with improved audio) and than i will experiment with coils.

Not sure of the coil type. It's 20cm dia and I assume it is the original. It has 'Waterproof search coil' embossed in the plastic top of the head. I'm wondering how I can get inside it without wrecking the plastic case. Any ideas?

[ivconic]

Not sure of the coil type. It's 20cm dia and I assume it is the original. It has 'Waterproof search coil' embossed in the plastic top of the head. I'm wondering how I can get inside it without wrecking the plastic case. Any ideas?

Sharp knife and retract it in stitch between upper and lower parts.
I think it is omega coil, most likely. But it could be also concentric..