Magnum on steroids!

[ivconic]

Can somebody plz tell me what are those marked points? I tried to find on schematic, but no luck. Thank's.
[ATTACH]37722[/ATTACH]

"A" and "B" are for switch, 1 or 2-tones audio.
"C" is optocoupler.
"E" is inductor.
For "E" you can put simple wire junction.

[CDI]

"A" and "B" are for switch, 1 or 2-tones audio.
"C" is optocoupler.
"E" is inductor.
For "E" you can put simple wire junction.

Many, many, many thank's Ivica. Nothing without you.

[Artyom]

Hello ivconic Explain the purpose of variable regulators R35, R42, R59, R60, R90. Thank you.

[ivconic]

Hello ivconic Explain the purpose of variable regulators R35, R42, R59, R60, R90. Thank you.

R35= Basic treshold
R42= additional Treshold for 2-tone option, important at switching/biasing the optocoupler
R59= can be omitted (shorted) or fixed value = additional precise adjustment for "audio pitch", affects frequency and duty cycle at audio generator.
R90= Audio pitch, audio frequency, also can be fixed value, according to your own preference
After playing a bit with R59 and R60 i got the impression that those two values can be completely omitted or put as fixed values, not important benefit from having those as variable adjustments.
R35 and R42 are somewhat tricky to adjust for nice working 2-tone option. Otpocoupler choice can play significant role here.
I think multiturn trimmer potentiometer is mandatory choice here, just as it is case at original Golden Mask detectors.
I used ordinary trimmers and i faced somewhat difficulties to adjust them properly. My mistake...

[ivconic]

Now... this is interesting!
Next logical question would be; "what if i can't obtain "1522" otpocoupler nor i can't find the next best match?"
I struggled to decipher the "1522" label on original otpocoupler in Golden Mask detectors.
Most probably it is "Made in China" product with not-possible-to-decipher label!
"Shoo Mang Fu Tao" kinda labels, but this time with cyphers.
Well... in that case we are in troubles, because most interesting feature; the 2-tone, will not work properly.
But with a bit of "trimming" here and there; one can come to decent solution even with another kind of otpocoupler here.
One of the ideas how to trimm it with different optocoupler:

Main point here is to make the led diode and transistor inside the optocoupler to be "sensitive" in a range.
Personally i am more impressed with results achieved with diy vactrol as at Dooley's project.
This thing can be modified with use of diy vactrol, interesting to think about!

[Artyom]

Thanks for the reply. Not seen on the ground balance control scheme. The adjustment is carried out?

[ivconic]

Thanks for the reply. Not seen on the ground balance control scheme. The adjustment is carried out?

"...R90= Audio pitch, audio frequency, also can be fixed value, according to your own preference..."

This is typo! It should be "R60= Audio pitch, audio frequency, also can be fixed value, according to your own preference..."

[Artyom]

What distance you get to the coin in the air and a size of the coil? The receiving coil is non-resonant? If you make a dual-frequency device to switch the frequency of the generator only, no longer need to configure anything?

[ivconic]

What distance you get to the coin in the air and a size of the coil? The receiving coil is non-resonant? If you make a dual-frequency device to switch the frequency of the generator only, no longer need to configure anything?

Size of coil is 30x28cm, distance in air for 1 euro coin is 35cm.
No, receiving stage is wideband. Nothing special with RX coil.
Frequency is switched simple with changing caps in LC tank.
Nothing else needs to be done.

[Artyom]

true I made changes to P 35, 42 on the board? I can not attach an image ...

[ivconic]

You have to put it into ZIP or RAR archive.

[scs]

When operating the ground balance with this type of filter to a lot of signals from earth salts. Another reject ground channel similar in Tesoro Golden Sabre must. Many details of the change in tone .Faults in filters?

[ivconic]

When operating the ground balance with this type of filter to a lot of signals from earth salts. Another reject ground channel similar in Tesoro Golden Sabre must. Many details of the change in tone .Faults in filters?[ATTACH]37751[/ATTACH]

Actually GEB is working very fine and accurate at this detector.
It is the DISC which need improvements, it is not quite accurate at higher depths than 10-15cm in a soil.
Medium sized rusty iron pieces are easy fooling it.
That's the only drawback at this detector (also explanation why it is so successful "collector").
Thanks for the suggestion! I will try that way.
What a coincidence; i am just making another TH unit!
In a few days i will report here the news.

[Sean_Goddard]

Had some PCB's made up of "mag_redu_pcb" version:using 1206 sized SMD components.
Should arrive this week Tuesday.
I have been studying the schematics and PCB layout this morning.

Why the shape? What case is it going in please?

[CDI]

Why the shape? What case is it going in please?

Cause fit into Bulgarian case for Terminator, Golden Mask...etc.

http://www.emporion359.com/userfiles...roduct_927.jpg

http://s2.dmcdn.net/OMWoi/1280x720-OzI.jpg