Sandbanks

[symon mark]

Hello everyone.
As far as I can recollect, the construction information does not mention a Faraday screen for the search coil. No doubt then, ground capacitance effects will become a problem.
I have built this detector again without the coil screen. Has any one built this detector with a Faraday screen on the coil? Any help on this would be appreciated.
I got around the Toko coil problem by using a MAXIM MAX761CPA switch mode control ic powered from a separate battery. I hope to upload the details of this once I have sorted out my scanner.
Best regards
Symon.

[C.Pruysers]

Re: Sandbanks

Symon . If you are using a seperate battery , why not use that battery directly to get your secondary power supply as done by the Toko coil . I built the sandbanks as per schematic but did not place the IC infront of the Toko coil . All I did is disconnect the 78LO12 from the diode and put a battery inplace of it . ( + on the 78LO12 and the - on the OV ) . If you can find the Toko transformer later on you can put the IC back in and connect the diode to the 78LO12 again . As far as the coil goes , I never used a Faraday shield on my coil and never had any negative result by doing it this way . The Sandbanks is a nice PI Detector with a lot of possibilities . Kees

[symon mark]

Re: Sandbanks

Kees
thanks for you help on this.
Best regards
Symon.

[Serafin]

Re: Sandbanks

the disconnect the 78LO12 from the diode and put a battery inplace of it, but whatever volts is the batery?

I have many toko transformers but no is mark 87bx135 as I can know as can replace the toko 87Bx135?

You have the datasheet of toko 87Bx135?


Thank
Best regards

[C.Pruysers]

Re: Sandbanks

Serafin . Build the wholw detector as if you had all parts . This you should do because lateron you may find the Toko transformer .and you could just mount it on the PCboard . For now don't put the IC3 in its socket and disconnect D1 and C6 from the IC8 . On the i/p of the IC8 you connect a + of a 12V supply ( use two 9V batteries in series ) . The - of the battery goes on the OV . Now you will get a little lower voltage than 12 V but that does not matter . Don't forget the capacitors Cx and Cy ( fig 1 of Improving the audio quality ) . So .... don't leave anything off the PC board . Just disconnect where I told you . Kees

[C.Pruysers]

Re: Sandbanks

Serafin . By the way ,I have not been able to find the Toko transformer anyplace . Would be nice if anybody had any info about this article . Kees

[Serafin]

Re: Sandbanks

Thanks C.Pruysers will try it late but

[Serafin]

Re: Sandbanks

Hi. C.pruysers

If I connect one second batery,it is necessary to use the CMOs 4011cp(ic3)?
or this IC3 is not necessary?

Thank best regards

[C.Pruysers]

Re: Sandbanks

No Serafin . You can leave IC3 out . ( if you can find the TOKO transformer lateron you can place IC3 ) . Kees

[Carlos]

Re: Sandbanks

hello to all:
because they do not build the proscan that he is similar to sandbanks and the source of positive tension constructs with a 555 oscillator and a duplicator to it of tension? They can say like constructing a coil to me for a PI since the times that I had to construct to a coil for the detectors type VLF it uses aluminum paper for kitchen? and here I cannot do it?

Carlos

[Janotaking]

Hey guys, i've been working on this, and I need some help from you. I don't find these integrated circuits OC 1,6 - 5552 IC 5 - 7411 I've been in a store and I didnt find them, and the guy that worked there says that he don't know them, they have any other name? Theres something missing in the name? A number? Help guys I need this to finish the project. I've noticed some holes in the circuit that don't are in use what are them for? Im not talking about the border holes for the box. And one more thing I don't know where to find the place to put the resistor number 30 -> 1,5K and the number 35 ->100K they aren't in the component layout p.c.b draw. Can you tell me where they have to be placed?

Thanks a lot guys.

See ya. xD

[Qiaozhi]

Hey guys, i've been working on this, and I need some help from you. I don't find these integrated circuits OC 1,6 - 5552 IC 5 - 7411 I've been in a store and I didnt find them, and the guy that worked there says that he don't know them, they have any other name? Theres something missing in the name? A number? Help guys I need this to finish the project. I've noticed some holes in the circuit that don't are in use what are them for? Im not talking about the border holes for the box. And one more thing I don't know where to find the place to put the resistor number 30 -> 1,5K and the number 35 ->100K they aren't in the component layout p.c.b draw. Can you tell me where they have to be placed?

Thanks a lot guys.

See ya. xD

The ICs you are looking for are these ->
http://www.maplin.co.uk/Search.aspx?MenuNo=12494
http://www.maplin.co.uk/Module.aspx?ModuleNo=2889

R30 is probably wired onto the headphone socket, and R35 is on the PCB to the right of IC7, just above R8.

[Janotaking]

Sorry, I've told it wrong, I don't have the 7091 CI, what his is name?

Thanks a lot for your help.

[Janotaking]

I didn't understand yet how to improve the audio quality, where should I put the Capacitors? I don't see any info image.

Thanks, Stay cool.

See ya

[Qiaozhi]

Sorry, I've told it wrong, I don't have the 7091 CI, what his is name?

Thanks a lot for your help.

It's not a 7091, it's a 709.
If you look at the parts list you will see that (for some strange reason) they have put an extra number at the end of each component name. This number represents the number of these components in the design. For example:
5552 - means there are 2x 555
7091 - means there is 1x 709
7411 - means there is 1x 741