Wire thickness of Coils for VLF Detectors

[Dixix]

I would like to make a DD coil myself (for TGSL).
Now there are various recommendations here in the forum ...

I'm interested in the thickness of the wire is to be used. In other words: How thin can be a wire?
I have old transformers. I would like to use the wire. The Wire thickness I measured: is 0.14 mm. The wire is too thin? Maybe too much resistance? Is it important with coils for VLF detectors?


Thanks for hints!
Dirk

[Davor]

You'll find a recipe for building a TGSL coil, and if you want to use thinner wire for Tx you'll have to make a multi-strand wire of the thinner wires. Tx is critical because if your coil has more resistance the coil Q-factor will be lower, the oscillator will have problems starting, perhaps the amplitude will not reach maximum, and it will suck more current. For Rx of a TGSL you can use even thinner wire than that with no problem.

[Dixix]

Thanks for the valuable information. I opened an old broken MXT coil some time ago. Now I understand why in the old defective coil, one "D" is wound with thicker wire and the other "D" is wound with thinner wire.
Then I can at least RX - wrap coil with the thin wire.
Dirk

[Davor]

Ideally both wires would be made as litz wires, as a perpendicular cross section is very small, and eddy currents are much smaller. So in case you have no problems making a multistrand thick wire - that's even better than a single strand thick wire.

[Dixix]

You mean it's better to use litz wire? Very interesting! I've only ever used litz wire in coils for PI detectors ....?
These are all very valuable information!
I will start looking for other old transformers. (This is not as expensive as new wire to use!) I think it is good to build more coils. Experiment! And thus to collect many experiences. This is all very exciting!
Dirk

[6666]

I will start looking for other old transformers.

Also look for fans in microwave ovens and degaussing coils in large TV's

[Dixix]

Sometimes is mistaken man ...... The wire is thicker than I first thought. I do not have a digital caliper. The first time it was a reading error. The right measurement is 0.24 mm.
Is this wire size well suited for self-made coils of Silver Dogs TGSL kit?
I hope that. So it is not tragic if the first coil is not working as expected.
I've seen quite a few constructions in the forum. For coil winding.
Important perhaps is a turn counter turn assemble?
I've always built only single coils. This is relatively easy. But now I want a DD coil. And if we succeed, the more difficult variation - a concentric coil.
A good coil is the heart of a well-working detector ....
Dirk

[Davor]

A good coil will have inductance and resistance close to the original. Lower resistance is better, but such a coil is heavier. Balance is a matter of geometry.