Real Metal Detectors

[Fred]

Hi, Fred, thank you. are sure it's 3 pf? then what's the smaller cap?
BTW fellows, don't you think this board is double sided?

Hi ,
The smaller cap is 1uF.Yes, it is double sided PCB.
Your last pictures are interesting, should be easier to trace diagram now.
The driver os the big transistor seems to be a 2SA733 , so just a PNP AF amp.driver, so final must be NPN .Pinout is OK.
Also the 2 others small signal transitors are BC327 and 337 , looks european to me,(733 was not) and relatively old (modern guys use BC557 and 547 ).
Regards,
Fred.

[amtech2005]

Real Metal Detectors

I just posted this photo for an example of being careless. Siemens is a big Company , I never heard of Simens ????.....To spell wrong or not spell a name at all is very careless . Some People do not take manufacturing serious , or do not have pride in their workmanship............I am trying to rememember where this photo was on this Forum ???...My Pride of alzheimers ...........Take care all........Eugene

[Aziz]

Hi ,
The smaller cap is 1uF.Yes, it is double sided PCB.
Your last pictures are interesting, should be easier to trace diagram now.
The driver os the big transistor seems to be a 2SA733 , so just a PNP AF amp.driver, so final must be NPN .Pinout is OK.
Also the 2 others small signal transitors are BC327 and 337 , looks european to me,(733 was not) and relatively old (modern guys use BC557 and 547 ).
Regards,
Fred.

Hi Fred,

BC547 and BC557 are low current (max. 100mA) types. BC327 and BC337 are high current versions (max. 800 mA). It depends on the application and very likely, they can not be replaced.

But if you use the BC547 / BC 557, you should replace them with BC550 and BC560. They are both low noise transistors (max. 100 mA).

Regards,
Aziz

[Fred]

Hi Fred,

BC547 and BC557 are low current (max. 100mA) types. BC327 and BC337 are high current versions (max. 800 mA). It depends on the application and very likely, they can not be replaced.

But if you use the BC547 / BC 557, you should replace them with BC550 and BC560. They are both low noise transistors (max. 100 mA).

Regards,
Aziz

Hi Aziz,
I know BC547 to be more like 500ma Ic, so not an enormous difference with BC337,but you are right, there is a difference.
Most of the time they can be swapped, but characteristics may change with manufacturers of course.
Anyway my comment was ironic (should i say...sarcastic ?? .)
Best regards,
Fred.

[Alex]

for Eugene

hello

This is a link to find a Simens detector .The picture was put in the forum by Aban whits lot of words but nothing real...Maybe just a a scam.
SIMENS PI DETECTOR
Enjoy
Alex

[michael]

Hi, some years ago I acquainted with a guy who had a PI with name Siemens (zimens accent) of course With a name on box. was obvious a neat homemade device. he was reluctant to see the LCD every time turned it on.
I pretended to ignorance as only important thing for me all time is device capability and never deal with the firm name or reputation.

only device capability and work range. we went for a test in one area, albeit was a good/acceptable PI but not better than our first PI, so gave up buying device or take him to our serious locations.
But MDL is another thing eats all other PIs.

[amtech2005]

Real Metal Detectors

Hello Michael , I forgot to tell you , that I did find a MDL 2000 "Log-search" Metal Detector , "CIRCA or year 1991" used for the Timber industry , and I am pretty sure , that is what your "Mystery P.I. Metal Detector" was originally used for . And it was 110/220 a.c.
line powered and was mounted next to a log conveyer belt . This is my final "Observation / Interpretation / Calculation / .......And this is My Final Answer ,and it is used somewhere where logging is still a Very Big Business........"Canada" ????..................Have a Good Day !!!..........Eugene

[michael]

Hi Amtech. thank you man. then could you please tell about the maker address? where is it or how can make a connection with them? if there is many similar things in base constructions between them please tell with PM.

[amtech2005]

Real Metal Detectors

Sorry it took so long , but here is the company logo to look for on your machine , or your search coil !!!! A U.S. company in New York State . They made a model in 1990 marked MDL 2000. Here is the logo , but I am still not 100% convinced it is them , but they are the best lead or choice so-far !!!! They specialize in Lumber/Logs only and have a very good reputation , for many years . Remember , If we proceed with Caution , then we will find the Manufacturer !!!!..........Take Care everyone............Eugene

[michael]

Hi, thank you Eugene.good step.
I found the site, is sounds somehow suspect to me. is possible be their work.
I sent an e-mail to sales Department and questiond about MDL 8500 with a picture of MDL box.
I think if other members do this be better to get a result.
maybe won't notice to a single e-mail.
It seems they produce industrial MDs, the only one handheld MD is their probe 2100 as you see:

[Morgan]

MDI

Hi, thank you Eugene.good step.
I found the site, is sounds somehow suspect to me. is possible be their work.
I sent an e-mail to sales Department and questiond about MDL 8500 with a picture of MDL box.
I think if other members do this be better to get a result.
maybe won't notice to a single e-mail.
It seems they produce industrial MDs, the only one handheld MD is their probe 2100 as you see:

Hi

This MDI 2100,its the same as the RED BARON metal detector,only painted in blue color .

[amtech2005]

Real Metal Detectors

Morgan , You are right , it looks like a discovery Treasure Baron . So they are just re-selling , with their own MDI label slapped on it !!!!! Good Call , I did not even notice that !!!! . I need to up-grade my glasses. I still think that MDI inc. makes the MDL 8500 , but we will wait to see if Michael gets an e-mail from this manufacturer . I have a gut feeling , we are close to the correct information about this "Big Mystery" ...................Eugene

[Alex]

HI Michael and all


This is the answer of MDI to my mail (I,VE SENDED THEM ALSO THE PICTURES OF MDL 8500 INSIDE AND OUTSIDE)

,,,Unfortunately, I can not identify what metal detector you have, and have not seen this product before.

You might try entering the model number into a Google search on the internet and see if it comes up. I was not able to locate anything on the web for you.

Sorry I was not able to help.

Regards,

Greg Hameltt
Metal Detectors, Inc.
(541) 345-7454

so our search must go on....
Don,t give up!
Alex

[Max]

but the idea that was a conveyor mounted thing is still the key: it's a clone of something used for similar purposes.

Kind regards,
Max

[amtech2005]

Real Metal Detectors

Hello Max , Yes conveyer mounted , and also , do not forget that something was unsoldered by the power supply. Original operation was 110/220 v.a.c. Also look at this photo again , I made one blue circle to show ribbon cable ,and the other circle shows insert snaps for "made in usa" white box can slide out , NOT Soldered in ???. More writing might be on the under-side of white Box ?????????????? Down-under. Maybe Michael can check if something we missed is covered up , and then we can see "Full PCB Board !!!!!!!!!!! Celeron inside might give a clue , or even company contact information !!!!!!! Also what does inside the "pointing arrow" say ???..............Eugene