2 boxxxx :)

[chemelec]

chemelec, in past post, he show one tx whit 555, on modifications at two boxs of rakes, after also he discontinued these idea and project, please say why?
detectoman

I'm Not sure I Understand.

But iIf I discontinued a project, it was probably because it gave Poor results.

[chemelec]

chemelec, in past post, he show one tx whit 555, on modifications at two boxs of rakes, after also he discontinued these idea and project, please say why?
detectoman

I'm Not sure I Understand.

But if I discontinued a project, it was probably because it gave Poor results.

[chemelec]

chemelec, in past post, he show one tx whit 555, on modifications at two boxs of rakes, after also he discontinued these idea and project, please say why?
detectoman

I'm Not sure I Understand.

But if I discontinued a project, it was probably because it gave Poor results.

[kt315]

But at 2Box oscilators with one 555 and one transistor we are ok.

Geo, I have wrote the locator must give 110-115 Volts on tx coil (ONE HUNDRED TEN-ONE HUNDRED FIFTEN VOLTS). can you get the meander in your schematic? I doubt. you certainly can get more voltage, maybe 300-450, but in schematic like PI driver on MOSFET, like to 'delta pulse' form, but not the meander.

yours.

[nelson]

Easy two box

Hi Gary. Here i m sending two pictures of a two box metal detector that a friend send me. By now i lost his email, so i can´t talk to him again, but if he is reading this post i ll be very happy to see a note of him.
He send this images from an old book about metal detecting, so if anyone can review this circuit and tell us if he think that may work, please let us know.
The circuit doesn´t have audio, just the meter. I also have details of the mounting part and the coils if anyone wants to know more.
Regards
Nelson

I'm Not sure I Understand.

But if I discontinued a project, it was probably because it gave Poor results.

[Qiaozhi]

Hi Gary. Here i m sending two pictures of a two box metal detector that a friend send me. By now i lost his email, so i can´t talk to him again, but if he is reading this post i ll be very happy to see a note of him.
He send this images from an old book about metal detecting, so if anyone can review this circuit and tell us if he think that may work, please let us know.
The circuit doesn´t have audio, just the meter. I also have details of the mounting part and the coils if anyone wants to know more.
Regards
Nelson

This circuit is from "Building Metal Locators, A Treasure Hunter's Project Book" by Charles D. Rakes. It was published by TAB Books Inc.
I have a hardback first edition copy dated 1968. ISBN 0-8306-0606-1
The paperback version is ISBN 0-8306-2706-5

It is claimed that this detector can seek out average to large metal objects that are buried as deep as 3 or more feet. If you have any pages missing I can scan them in and post here.

[nelson]

Two box metal detector

Hi Qiaozhi and thanks.
Yes i really like to have the full article about this detector. Also i ll like to know if the book shows anything about how to place sound.
Can you also send the book index?
In advance many thanks.
Regards
Nelson
ce3llp@mi.cl
Santiago-CHILE
SA

This circuit is from "Building Metal Locators, A Treasure Hunter's Project Book" by Charles D. Rakes. It was published by TAB Books Inc.
I have a hardback first edition copy dated 1968. ISBN 0-8306-0606-1
The paperback version is ISBN 0-8306-2706-5

It is claimed that this detector can seek out average to large metal objects that are buried as deep as 3 or more feet. If you have any pages missing I can scan them in and post here.

[chemelec]

Hi Qiaozhi and thanks.
Yes i really like to have the full article about this detector. Also i ll like to know if the book shows anything about how to place sound.
Can you also send the book index?
In advance many thanks.
Regards
Nelson
ce3llp@mi.cl
Santiago-CHILE
SA

Yes I have seen that one before.
To me it seems a bit too simple to really be that sensitive in most ground. But a lot has to do with coil alignment.

[nelson]

Two box

Hi Gary.
Yes it looks simple for me too, but i think it will be a good point of start if i make it.
What about the two box re-design Gary?
Regards
Nelson

Yes I have seen that one before.
To me it seems a bit too simple to really be that sensitive in most ground. But a lot has to do with coil alignment.

[chemelec]

Hi Gary.
Yes it looks simple for me too, but i think it will be a good point of start if i make it.
What about the two box re-design Gary?
Regards
Nelson

I'm Working on it.

However there are some Definate Changes between the Schematic I Saved fro this posting, compared to the PCB Overlay, also posted here.

So Now I am Not Sure Which is Correct????????

For One, the Overlay shows a 4049 IC, but only 14 pins.
A 4049 is 16 Pins.

The Overlay, also Does NOT show the Supply pins Connect to Supply Voltages.
How can this IC Run? REALLY STRANGE!

Additionally the Schematic Only Shows Q1 and Q3
But the Overlay shows Q1, Q2 and Q3.

Lastly there are Two 1N4150 Diodes on the Schematic, But they do Not appear on the Overlay, nor does there seem to be any Connection points for them to mount too. ???

There are a few other variations also.

So the Problem Now is: WHAT IS CORRECT?

Or am I Missing Something in my old age?

[kt315]

Or am I Missing Something in my old age?

Gary, the authour did the schematic on a dummy bread board. Ivan himself did not make a PCB. some people did the layout image what you see. maybe best solution will be do Overlay as new? I do not know...

Two 1N4150 Diodes on the Schematic

I did add these like to Tesoro's schematics. not originally...
pls also add a place on PCB for capacitor I image here. I think may it is necessary?..
regards.

[chemelec]

Or am I Missing Something in my old age?

Gary, the authour did the schematic on a dummy bread board. Ivan himself did not make a PCB. some people did the layout image what you see. maybe best solution will be do Overlay as new? I do not know...

Two 1N4150 Diodes on the Schematic

I did add these like to Tesoro's schematics. not originally...
pls also add a place on PCB for capacitor I image here. I think may it is necessary?..
regards.

What about Replacing Q1, Q2 and Q3 with an LM386.
(Possibly also a Trimpot for a Preset Volume adjust, which could be a changed to a regular pot if someone wants that.)

I Don't have that Crystal, the Closest I can come to it is a 27 mhz CB Crystal.
All that will probably do is change the resonant frequency and coil size a bit.

Other than that, I believe I have all the parts in my stock.

ALSO:
Chris2 WROTE:..but you still need the GATE IC for the TX circuit!

I Assume that is where these Two, 1N4150 Diodes are to be used?

[kt315]

What about Replacing Q1, Q2 and Q3 with an LM386.
(Possibly also a Trimpot for a Preset Volume adjust, which could be a changed to a regular pot if someone wants that.)

good idea, Gary!

I Don't have that Crystal, the Closest I can come to it is a 27 mhz CB Crystal.
All that will probably do is change the resonant frequency and coil size a bit.

clock crystal 32 kHz is very commonly used. you can find it on old system PC board without a problem. all old and new China hand clock with LSD has it. but if to use [xx] mHz the divider will take some additional power loading I see 26 kHz crystal in Whites schematics. is it accessability in your world? I do not see a problem, if you will take 100 kHz crystall. ceramic crystalls on 300-400 kHz you can try to ask in a shop, used in TV remote control.

Other than that, I believe I have all the parts in my stock.

ALSO:
Chris2 WROTE:..but you still need the GATE IC for the TX circuit!

use 4069 or 14069. no a risk!

I Assume that is where these Two, 1N4150 Diodes are to be used?

1N4150 is such as 1N4148 but on more low voltage. there are not a big difference what diodes you want to use in this schematic. again, no a risk.

[Qiaozhi]

Hi Qiaozhi and thanks.
Yes i really like to have the full article about this detector. Also i ll like to know if the book shows anything about how to place sound.
Can you also send the book index?
In advance many thanks.
Regards
Nelson
ce3llp@mi.cl
Santiago-CHILE
SA

Pages 56 to 64 of Chapter 4 attached below, plus list of contents:
More to follow...

[Qiaozhi]

Pages 65 to 74: