Whites ???

[Altra]

It's also possible R24 was never installed, instead with a jumper? I was thinking IC4 is a CD4538 or similar and IC6 a CD4066.

I didn't open your lay file, only your jpg.

Eric may remember this unit?

Nice puzzle

[ivconic]

[ivconic]

Carl was right; basically this is PI-1000!
Oh how blind was i all the time!
It was right there in front of my eyes all the time!

[Qiaozhi]

Carl was right; basically this is PI-1000!
Oh how blind was i all the time!
It was right there in front of my eyes all the time!

[ATTACH]37565[/ATTACH]

Schematic and User manual:

[Geo]

Carl was right; basically this is PI-1000!
Oh how blind was i all the time!
It was right there in front of my eyes all the time!

[ATTACH]37565[/ATTACH]

On your pcb i measure 10 ICs but on schematic there are only 8!!!!

[Koala]

Someone here has a PI 150

They may send you a photo of there board if you ask.


Might be able to eliminate or confirm one avenue


https://translate.google.co.uk/trans...07&prev=search

[ivconic]

Schematic and User manual:

Yes that is the schematic i was comparing with this pcb.
So far i traced maybe 30% and those are equal.
But also at some point i founded out small differences.
It seems like PI-1000 but slightly modified.
I will try to complete tracing and naming the components on pcb draw and later i will post it here.
In meantime also discovered few minor mistakes (made by me) on the draw.
Tracing component by component is best way to correct such mistakes.

[ivconic]

On your pcb i measure 10 ICs but on schematic there are only 8!!!!

Will check that as my work goes on.
As i said; seems this is a bit different than PI-1000, maybe some unknown variant?

[ivconic]

Someone here has a PI 150

They may send you a photo of there board if you ask.


Might be able to eliminate or confirm one avenue


https://translate.google.co.uk/trans...07&prev=search

I am not well informed about PI150.
Could it be that it is based on PI-1000 design?
Maybe those are very similar?

[ivconic]

Definitely Bill's schematic and this pcb do not match 100%.
This is not exact "PI-1000", this is some variation, even more interesting!
According to pcb; pins 12. and 11. at 4016 are reversed on schematic.
Bill's mistake or...?
More to come.

[ivconic]

This is as far as i can get relying on PI1000 schematic.
Definitely this is not PI1000 but something based on similar design and extended more.
Without additional information this is not possible to solve easy.
But i am still convinced that this is very interesting project.

[nickel_n]

Here is the original ( I think) Pi1000 schematic.
It may help you

[ivconic]

This is as far as i can get relying on PI1000 schematic.
Definitely this is not PI1000 but something based on similar design and extended more.
Without additional information this is not possible to solve easy.
But i am still convinced that this is very interesting project.

[ATTACH]37574[/ATTACH]
[ATTACH]37575[/ATTACH]

[Ferric Toes]

This is as far as i can get relying on PI1000 schematic.
Definitely this is not PI1000 but something based on similar design and extended more.
Without additional information this is not possible to solve easy.
But i am still convinced that this is very interesting project.

[ATTACH]37574[/ATTACH]
[ATTACH]37575[/ATTACH]

Whites UK did some designs off their own back in the 1980's. One was an 'professional' PI, which didn't look much different to a hobby machine. Another was a ferrous/non-ferrous PI discriminator which never got into production. I have the schematic of the latter somewhere, as at that time they wanted to get me involved in it as well. It seemed to work OK, but it didn't like mineralised ground.

Eric.

[ivconic]

Whites UK did some designs off their own back in the 1980's. One was an 'professional' PI, which didn't look much different to a hobby machine. Another was a ferrous/non-ferrous PI discriminator which never got into production. I have the schematic of the latter somewhere, as at that time they wanted to get me involved in it as well. It seemed to work OK, but it didn't like mineralised ground.

Eric.

I have always been amazed with Bill Lahr's (and few other guys) dedication to draw all those schematics manually and to make splendid collection of all those nice vintages.
I find that as priceless heritage for future generations of hobbyists.
It is obvious that genuine documentation from designers will never see the daylight and always will stay as privilege to limited number of people.
And that's why i am pushing these kinds of works; to complete, fulfill and continue this story until one day we manage to cover all the models ever produced... and hopefully few of those which never got into production.
Along with that; i find this as great amusement and joy. For me this is excellent way to spend time, on second place just after real searching with detector.
Also from time to time we can see some interesting and nice (yet abandoned for some reason) solutions in those old projects.
Man can learn a lot from those.
This particular project is very interesting to me.
Eric if you can recognize it; please tell here.
Also if you have similar works to share; please do.
That will bring a lot of joy to some of us here.
There is no sense in keeping such oldies in a closet anymore, whole (relevant) MD world already completely turned to DSP and from now on it will be the competition only in more jingle&bells and prices cutting between manufacturers.
Now... i am not addressing this to you personally, please don't guess me wrong; as far as i am concerned you already gave tremendous contribution to md society.
I am addressing this generally to all people who possibly might have something kept and hidden from old times and do hesitate to share.
About those you mentioned that you might have, if you will; please do share here. Would be really nice to see such stuff.
Cheers!