Building My Own PI Detector

oldrunner

Junior Member
Joined
Dec 29, 2008
Messages
93
Location
Kerrville, Tx
The plans are located here http://www3.telus.net/chemelec/Projects/Metal-2/Metal-2.htm
At the present time, it's working and with minimal adjustments and using zipcord to connect the coil, it detects a dime at 7" in the air. I'm sure it will do better when I make my final adjustments and use coax to connect the coil. My next step is to build a waterproof( not for diving but for surf ) enclosure. At the moment I'm looking for a cheap source for plexiglass. It looks like I'll have about $225 invested in it. The 9v battery in the picture is just to tilt the meter to eliminate the glare in the picture, it isn't part of the detector.
 

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Alright now your talkin! Keep us posted on how it goes. What is the range of the pulse delay? Ok good hunting and I hope it works well for you.

John T.
 
Pulse delay is 17 - 43 uS but you can change the circuit to just about any delay you want. I'm going to trade out the Receive Time, Pulse Width and Delay Time pots for trimmers and enclose them along with the Freq Sw. The only 2 controls on the outside will be Null and On/Off/Vol. Maybe the Pulse Delay also but I want to experiment first.

I bought the coil prewound by Gary since he has the equipment to wind one better than I can. I wanted a good coil to start with because if there was a performance issue then the first thing I would suspect would have been the coil. Once I finish the detector, I may wind my own, possibly a double coil. :D
 
Its looking good.

Coils are always a problem. I would make my own and with static pulse machines square or rectangle shapes seem to work best though on land the corners can be a problem.

A cheap kit that has the disadvantage of not being as adjustable out of the box is the Goldpic is by Trevor Hill. Its non motion though, which makes coil construction very much easier. My best home made coil was a three foot wide by one foot beach coil. On the beach you would just hold it directly in front (non motion, so no swinging), walk up and down the sand covering a full three feet and there was no posibility of missing anything. (anyone interested just type Goldpic into any search engine).
 
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