Goldscan Pulse IV

		Quote:			Posted by goldigger
	Eugene 52; I think you made a small error, about the 74HC4538, in one respect: What is the operating voltage, in the circuit, in which it is subbing? If its greater than 5 volts, it will self destruct, just like Mission Impossible tapes. If the circuit is 5 volt, it will work OK. Brian AKA goldigger

Hello Goldigger . You are correct . When I checked the cross reference the numbers matched , but I re-checked the datasheet and the maximum supply voltage for fairchild is -7 volts maximum and not -18 maximum like the CD4538. It is not a 100% perfect replacement !!!
Now Electrosoft has no choice , he must use the CD4538 because the design is -12 volts . I will try to e-mail him . Regards.........Eugene


If you read the 2 pdf files here , it is an identical replacement except for the supply voltages !!

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Hi,

I am very grateful for the info here but I have the following questions:

Just wondering if there is more info on building the rest of this to package.  Is there a parts list or is the job to read off the schematic? 

I wonder for example is the piezo of a special type?

What sort of coil (or how do I make one)?

One schematic shows the battery meter as 500 milliamp and the other 500 microamps.  Which is it?

Finally (hoping to make life easier) are there any kits available?

Thanks in advance!

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		Quote:			Posted by chudster
	Hi, I am very grateful for the info here but I have the following questions: Just wondering if there is more info on building the rest of this to package.  Is there a parts list or is the job to read off the schematic?  I wonder for example is the piezo of a special type? What sort of coil (or how do I make one)? One schematic shows the battery meter as 500 milliamp and the other 500 microamps.  Which is it? Finally (hoping to make life easier) are there any kits available? Thanks in advance!

Ah, Grasshopper, you have come to the right place . . . yet your journey has just begun.

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Hi Eugene.

Thanks so much for the speedy reply!

I am planning for a future vacation with the family to look for nuggets in our heavily mineralized soils and want them to have a good chance of success.  I am electronics literate so it would be possible to make a couple for the family.  I can't afford four state of the art Minelabs (!) but as this seems to be an older design I wondered how it stacks up against modern PIs for that application?

Also I saw the sideprobe in the picture.  Is this a useful addition?  I presume it helps the tradeoff of the larger coil which is not as useful for localisation and is just switched in and out.  With a low diameter it would have many more turns for the same resistance as the main coil.  Any idea on the usefulness and winding specs for this?

Finally, do you have any suggestions for suppliers or improvisation for the physical packaging (coil form, handle, forearm rest etc) as this would be my first detector project and I am not sure where these are sourced.

Regards,

Chudster


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Yep,  I am in Perth.

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