A plan to built the 1,5m going "Professsional Systems Schatzsuchgerät". In german and with no circuit, but perhaps it's of use somehow.
http://www.multiupload.com/5BMJAGXO1F
http://www.multiupload.com/5BMJAGXO1F


At least I found the schematic
- but near the IC it needs some little recovery.

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