Hobby Hybrid MD1

[dbanner]

The double-O and double-D are better for use in highly mineralized ground.

DFBowers design was primarily for beach detecting I think. I'm not sure. The concentric(centre) coil is best for normal beach sand.

If the beach has black sand, saltwater, or high mineralization, an OO or DD coil is better.

• Small to Medium (8"–11"): Better for target separation and sensitivity to small jewelry.
• Large (12"–15"): Deeper detection but may miss tiny targets in trashy areas

[dbanner]

I recall this schematic. Here contained in this scheme are "DISC" and "GEB" pots.

[Detectorist#1]

It is very interesting - this schematic is only idea or anonymous author made real unit with some tests.

[algan]

When you make dd or oo coils, try it with licendrat and you will see that there is a difference from the standard wire. You know that all dd impulses from Minelab are with licendrat.

[Detectorist#1]

Minelab try to patentee all concerned whit metal detecting. Below is patent for using a litz wires for MD coils from 1986. The problems are very hard finding for small quantity and very high price of these wires for DIY projects. The real improving is not very big for well designed coils with standard enameled wire or single multi-stranded wire cables.

[GeoMax]

It is very interesting - this schematic is only idea or anonymous author made real unit with some tests.

Hi Vladimir,

I think this is a redrawn schematic of the original SBG-PID from Sascho Bulgaria. The GB, Sampling and DISC circuit part are the same. Maybe other parts as well. I have not checkd it further.

[Detectorist#1]

Hi Chris,
I know this schematic, but continue to have some doubt for real ground balancing and discrimination capabilities of this schematic.

[dbanner]

The circuit was redrawn, but it is the same.

[Detectorist#1]

Hi dbanner,
The circuit is the same, but what is your opinion for ground balancing and discrimination capabilities of this circuit?

[algan]

I don't know what Chinese pulse antennas are, I'll buy one anyway, but it's good to have a factory dd coil from Minelab or a replica, but then you can try to make one yourself, but for testing boards, the original is best.

[scs-bg]

This scheme works similarly to Whites TDI. It has been tested. Discrimination is by conductivity. For this reason, silver is indicated equally with iron. Pulse detectors are not suitable for fields, places with rocks and large pieces of ceramics. They work better with DD and OO coils. They are suitable for work on the beach and in the forest. The best discriminator is a shovel... There is nothing to find with a detector anymore because almost everything is not deeper than 20 centimeters. There are now many Chinese detectors...

[scs-bg]

Many people think that pulse induction is something magical. In practice it is not. In practice an old analog "Violin" is much better.

[Detectorist#1]

Hi scs-bg,
Some of us are from younger generation and not know nothing for "Violin" detector. Give please some information for this detector.

[dbanner]

Hi dbanner,
The circuit is the same, but what is your opinion for ground balancing and discrimination capabilities of this circuit?

I am not sure what to make of this circuit. If SCS-bg says it's been tested, then it probably works. But I cannot say anything about the performance.
I never built it.

Take note of the AC coupled Rx preamp.

[scs-bg]

It's about an inductive balance detector with a discriminator indicator arrow - the old Bulgarian "Gadulka". Nothing can compare to it. These detectors do not miss anything in the ground. Nexus is something similar .