New Project

[Davor]

When you think about an E48 part as 2% tlerance, and, say, 68.1 ohm, you need to find a 1% resistor in a range 68.1 +/- 0.681 ohm.
Parts found in E6 range are vastly popular, and when designing things we all first look for those. It is relatively easy finding a 1% part in E6 range values, because those get passed to E48 and further. Go to google and type "E6 E12" and see the table. It is easy.

[homefire]

I always Ohm out Resistors no matter what the Tolerance Ratings. Found some Doozzies even from Reputable sources. The Chines parts I buy are always on the Ropes of the stated Tolerance but within.

[Davor]

And that's precisely why designers use values that are unique for, say, E96. When you need 220 ohm within 1% tolerance, you'll pick 221 ohm simply because those come exclusively within 1% tolerance. There are 220 with 1% ring on it, but it may happen that someone in a supply chain overlooks it. Ordering 221 is safe.

[Koala]

....its time to start a new homemade project. Im looking for an high frequency vlf detector( something about (40-70 kHz). Is there some shematic out there?

Might help if people share the strengths on weakness of projects they have built. So you can pick a project that fetches something new to the table.



IDX reliable discrimination not as good as the Bandido unless you turn it up higher. Then small silver on its edge starts to get discriminated out. Very reliable performer. I used this for a couple of years

Bandido less air test but greater depth in the field compared to the IDX. As tested on a real target in the field. True no motion mode is great around trees and for finding the size and shape of objects. Ground balance is critical. Get it wrong and you loose lots of depth. I used this for about a year.


I also have a factory 1260 and 1265 both hit target more reliably than my home builds. By which I mean when swinging over a very deep target it always beeps regardless of sweep speed. As tested in my garden and appears to transfer into the field. Seems to struggle on waterlogged coke filled fields. Not that I am the only one struggling in these conditions.



As I see it most of the VLF projects are pretty much the same performance wise. The Quasar ARM or similar would add a built in VDI.



Pity the Gold Bug 2 or similar hasn't been published as it would add another dimension. The Gold Bug Pro is micro processor controlled anyone know if the bug 2 is.

[Skippy]

Don't forget the Makro Racer Gold, the coils could be useful. And the schematic of the Racer 2 is discussed on a thread on here, plenty of similarities I guess.

[6666]

Prospekteur, Sounds like you are looking for a gold machine, Maybe its worth a look at this Lobo lite, from about post #204 onwards, look carefully at the coil info ,

PLEASE Note; the Lobo-Lite will only work with the Gold Bug, Gold Bug SE, Gold Bug DP, and Gold Bug Pro coils, or home built emulations of such, designed to operate around 19kHz.

It will NOT work with Gold Bug-2 coils (Gold Bug 11) which has an operating frequency of 71kHz, unless the filters and resonant caps are modified also.


http://www.geotech1.com/forums/showt...568#post170568

[homefire]

That's why I wanted to bump freq on the TGSL.

[Koala]

The Eldorado was used as a nugget hunter

http://www.treasurenet.com/forums/te...eldorados.html

Highly developed project with our Russian friends. Probably second most developed after the Quasar

https://www.youtube.com/watch?v=3

Seems to have nice audio in all metal mode.


Probably no good as a flake hunter though

[Koala]

Interestingly this guy can use any detectector but manly uses a modified lobos ST https://www.youtube.com/watch?v=H-CjXsI42sY


Wonder in what way its modified ?

I did watch part one of his video which is also good.

[Prospekteur]

@Koala.........really interesting Videos.....;-) .......ive used the lobo for several years as backup detector....i will build this machine......i miss him so much.....cant wait to turn him into live and hear him scream for the first time;-)

[Koala]

Found this a modified Lobo with VDI in SMT with our Russian friends

https://translate.google.co.uk/trans....ru&edit-text=