Geotech Treasure Hunting Project Problem

I have been looking at some of the VLF IB detectors on the Geotech website i was very interested in some of the old designs like the Magnum IB and some of the others are of interest as well i like the idea of being able to discriminate however when looking through the list of components some hard to get others near impossible asspecially the panel meters more than one system uses 50-0-50uA center Zero panel meter and another 100-0-100uA panel meter these are extremely hard to find or to expensive i was wondering is there any way around this say with a series of led's or maybe convert one of the very few still available center zero say 15-0-15V voltage meters if this is a good idea or even possible i would like to know how. I know you can discriminate with the voodoo project but still wonder if it is possible to overcome this limitation with these older designs. looking at modern digital panel displays 0-100ua but do these read negative values as well and can these be used with these older designs Just interested at this stage but would really like to know in case i endeavour to attemp building one of these. Graham

[Qiaozhi]

I have been looking at some of the VLF IB detectors on the Geotech website i was very interested in some of the old designs like the Magnum IB and some of the others are of interest as well i like the idea of being able to discriminate however when looking through the list of components some hard to get others near impossible asspecially the panel meters more than one system uses 50-0-50uA center Zero panel meter and another 100-0-100uA panel meter these are extremely hard to find or to expensive i was wondering is there any way around this say with a series of led's or maybe convert one of the very few still available center zero say 15-0-15V voltage meters if this is a good idea or even possible i would like to know how. I know you can discriminate with the voodoo project but still wonder if it is possible to overcome this limitation with these older designs. looking at modern digital panel displays 0-100ua but do these read negative values as well and can these be used with these older designs Just interested at this stage but would really like to know in case i endeavour to attemp building one of these. Graham

There are numerous sources of these meters on ebay. For example, here's one from China:
https://www.ebay.co.uk/itm/164444808...wAAOSwxxpfhhe0

[DonCaffeDelaSkobalj]

Hm. Really hard to find ? Mission impossible ?

DC Minus Zero Plus Panel meters 25μA - 10A.


https://aliexpress.com/item/1005002258942146.html?spm=a2g0o.productlist.0.0.5d 3a52f6ZYEZt9&s=p&ad_pvid=2021042403391736972528599 4030019669807_2&algo_pvid=d37ff962-2cd2-43f1-8b26-b0fb8a1d91d0&algo_expid=d37ff962-2cd2-43f1-8b26-b0fb8a1d91d0-1&btsid=0b8b034e16192607569822521e5303&ws_ab_test= searchweb0_0,searchweb201602_,searchweb201603_

[Graham]

Thatk you for that Guru it seems Australian ebay is a bit different to ebay UK.

[Skippy]

Choosing the correct search terms is the key to finding listings on eBay.
panel meter analog
moving coil meter
centre zero meter
panel meter 100-0-100

This last one gave some good hits on UK eBay:
[url]https://www.ebay.co.uk/sch/i.html?_from=R40&_nkw=panel+meter+100-0-100&_sacat=0

Also, do you have surplus electronics dealers in Oz ? Do ham radio clubs have flea markets / jumble sales / rallies where such stuff is traded ?