PI circuit modifications and identification

[ivconic]

Now I have to find which pot adjust the sample delay time I think.Im going to be looking at that schematic for a while.I think I will have big one printed at kinkos.Thanks a million Carl.

When you adjust it to work good as you expect - please inform us here about performances.
Just saw schematic.
Military equipment should be at least step forward over conventional, yet this mine searcher indeed looks a way over complicated, so i guess must be a good reason for that?

[Qiaozhi]

Now I have to find which pot adjust the sample delay time I think.Im going to be looking at that schematic for a while.I think I will have big one printed at kinkos.Thanks a million Carl.

Please see my reply in the Schematics Forum -> http://www.geotech1.com/forums/showp...62&postcount=3

[Brian Deese]

Oscilloscope

A 20mhz dual trace scope is good enough for metal detector testing and tuning isnt it? I am shopping for one,and I found one I like and the price is right.I believe it has an lcr meter made into it as well,I downloaded the manual going to read it tonight.

[Qiaozhi]

A 20mhz dual trace scope is good enough for metal detector testing and tuning isnt it? I am shopping for one,and I found one I like and the price is right.I believe it has an lcr meter made into it as well,I downloaded the manual going to read it tonight.

Yes, that would be fine.

[Brian Deese]

potential problem

I bought a scope but it wont be here for a few days,I have been studying the schematic,and the hammerhead article also. I think the circuits are very similar,this whites being over complicated though.I decided to set the machine up and turn on the pots to see what I could get out of it. Not much performance gain at all. I think I will look into the clock speed on this unit,it is so slow to respond I dont see how it was very useful.As I was turning the pots I stumbled on something very odd to me and it may be a problem or the problem. If you look at the pics where the amphenol socket is you can see two pink wires that are spliced to the main coil wires the large black wires.The pink wires are spliced to the outer sheild of the black coil wires and they use the terminals next to the coil terminals to pass through the amphenol socket.Well when I was adjusting a pot earlier I passed the screwdriver between the pink wire and the black wire it is spliced to and the machine signaled a target.So I put it between the other pink and black wire and got no response.It is repeatable every time the machine will signal. Ok so I thought there is something wrong with the sheild on this wire,so I cut the pink wire.The unit fault light came on and the machine is shut down,touch the wire back to the terminal and light goes out and machine works again.Ok so I said they have made the sheild part of the circuit and if I splice the two pink wires together that will satisfy the fault then I can check into this sheild problem.Not so! Splicing the pink wires will not satisfy the fault light. So what in the hell is going on here? Is there some sheilding strategy I am missing or is something wrong? I am ignorant at this point,the schematic is only for the circuit and not the loop as far as I can see. Oh on an up note I cant believe it but white's UK sent me the schematic today,I had emailed them weeks ago.