which vlf ?????

I think that vlf it s difficult project... I am interesting too!



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		Quote:			Posted by raff33
	hello drifter, you are right it is not easy to find a good vlf project to detect a metal and reject others........  but we wait hoping Eugene and others............have a nice idea about........ REGARDS............raff33

Hello Everyone . I think there are 3 or 4 vlf projects posted on this forum that have good discrimination . The circuit boards can be built without difficulty . And the best and easiest way to go when building a search coil is make one with DD configuration . Please search and study our entire "Tech Talk" area on the message boards page .

Best Regards..........Eugene

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		Quote:			Posted by raff33
	thanks Eugene for ansring ,but i meen each one capable to  (detect only one matal and reject others ? ) Regards.........raff33

Then I think what we need is to find are schematic's of older discontinued VLF Gold Metal Detector's Like Whites , Fisher or similar.

The Whites Goldmaster II is 48 khz and the Fisher Goldbug I was 19khz .  The Goldbug II at 71 khz , is still in production . Also Tesoro Lobo original version ran around 20 khz . What metals can be sharply notched out [not wide notch] , certainly not nickel , gum wrappers or pull tabs in the gold range . So it will take some thorough field testing after you build something , plenty of trial and error . Notch accept/Notch reject . Definitely a very good question to ask here on our Forum !!! Others are welcome to comment here .

HH........Eugene








 

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		Quote:			Posted by raff33
	for exemple TGSL it's good for discrimination (ferrous / non ferrous) but not capable de detect (silver / non cannet of soda ) LUC did a good Tesoro Golden Sabre nice jobe ....... You are not allowed to view links. Please Register or Login http://thunting.com/smf/vlf_designs/tesoro_golden_sabre-t9212.0.html -but this TGS can't detect gold and regect Copper  REgards........raff33

Also remember that some Tesoro models that had the ED180 discrimination circuits like the Eldorado and Vaquero has better or clean iron discrimination versus older Golden Sabre II ED120 circuit . So another thing to consider is after 60 degrees or so of iron discrimination you still have 120 degrees left . So when making your choice go ED180 with the highest operating frequency .
You also do not want a Metal detector that when filtering something out causes you to loose sensitivity to small gold .
A lot of parameters to consider when being so specific on what project you want to build . I think the Tesoro Lobo original VLF has ED180 and would be great to experiment with . Amigo II , Compadre and Cibola also have ED180 if I remember

correctly ?    we will discuss this more !!

HH...............Eugene


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Hello raff33 . Thats a good luck "Lucky Horseshoe" you found .

If you live in any old city and there have not been horses around for a hundred or more years , it means you uncovered something in an area that has a real good chance of more potential valuable Treasures . Be a Detective and always look for clues or patterns of all your finds in relation to the surrounding area , land or buildings when Metal Detecting , it will increase the real Good Finds .

Your English is fine , better than most people speak over here !! Just stay on our forum everyday and any broken language's will improove .

I was going to post a nice detailed Field Test and just noticed all attachments now are at a 500 kilabyte limit ,
 I think they did that special just for me . 

HH.............Eugene
 



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