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Im trying to make a gold scan 5 using the schematic posted on this site...can anyone tell me the main errors in the diagrams and also will the goldscan 4 audio circuit be suitable for this gs 5 ????
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Dave I haven't seen the full schematic for Goldscan 5, it ends up to the VCO point and possibly the rest can contain errors like you suspect there might be.
I suspect with the current information available on the forum it's hard to build it.
Why don't you go with the GS4, for example this looks more promising - Serbian Goldscan
In this post Eduardo posted what it seems nice version you may want to try. There's sprint layout available and even better turkish made PDF file for the PCB.
Haven't build it so I can't say if it works well or not.
Reg posted quite some time ago that it can be further improved by removing the pots there if you use low offset voltage op amps (2x quad op amp chips with <100uV offset).
Further the schematic can be improved by using MCU, shouldn't be too hard to get 5 output signals from a MCU. -
Hi Eclipse...i would really like to try and make a gs 5 as its one of my ultimate detectors that i would like to try and build and use on the beach...its a challenge to me in my situation in life.....i did notice in the schematic that there was a diode in the wrong place in the 5v transistor generator circuit and also the frequency tx control seems wrong...when you compare the sample generator schematic with that of gs 4 it looks correct...but not sure about the 4001 circuit which looks like some circuit delay to stop the blair on audio when power switched on..the ground cancell section i do not rea lly understand as i have no knowledge on how ground cancell works.Comment
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The 4001 looks to me as it's a type of auto-tune section. Maybe someone knows better. Here are some photos
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Hi Eclipse....This is the schematic that i already have to work with so i guess i will have to do my best to try and implement this with gs 4 audio and see what happensOriginally posted by eclipse View Post
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Gee no, don't know where I got these, from webz probably. Those are original boards.Comment
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im going to try and build gs 5 from the schematic and try and find a suitable audio schematic...ive been feeling even more depressed over last few weeks as nothing is going right for me so i need to stimulate my mind and try and do this gs 5 project !!! just the presets that se em very daunting
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If I were you would start from building the GS4. If you take a closer look at the GS6 (yes not a mistake, people called this mod GS6) link there I posted
you will see that the modified version is incredibly close to GS5 schematic.
From what's available as info for GS6 - the PSU, TX, Preamp, Gates & Integrators - it's all there and should be close to working (make a dual stage preamp).
All this can be taken directly to your GS5 build. So I'm suggesting you follow the GS4/6 to build the GS5.
After the signal integration (point A & point B on the Lugatek turkish PDF) is what's new in GS5. This part you may fail if there's an error. If you successfully build this section you're winner.
Yes audio sections can be borrowed. Must be absolute value VCO. There are few available here on the forum.Comment
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hi eclipse...i would have liked the two tone audio but maybe just have to settle for a single vco....i may try and build in a round 50mm tube as i did in my other project...i like the gs design as it has a frequency control which is a must on our local beach as much noise from road crossing electronics and amusement arcades...ive never had a detector with a frequency control....not sure about the ground cancell on the gs as ive never really understood how it works...and how it can reject iron as on the gs 5..if i can make a working detector on a verro type board in separate stages then i will be happy with something i can feel confident with on the beach.Originally posted by eclipse View PostComment
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I guess you should start and build the PSU & Timing circuit first.
PSU - just use minipulse one, you need +12V (GND), +5V, -5V.
I see lots of trimmers in the Timing circuit and no way of knowing the original settings, so this maybe a bust right from the start.Comment
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ive decided to try and make the gs 5 from the schematic....the first part of the schematic seems straight forward but i found a couple of errors...also the coil voltage in the diagram is regulated at -10v which i guess should be -12v...i want the circuits to fit into a 50mm tube so i have to use a verro type pcb's...i like also the gs 5 cause the tx frequency runs at around 3 khz which i read gives a better signal to noise ratio...i hope that i can build this cause it will be a great help to me on the beach.Comment
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Hi eclipse...comparing the trimmers between gs 4 & gs 5 it looks like most of the trimmers in the ground balance section are adjusted to give a 0v output from each op amp.Originally posted by eclipse View PostComment
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I'm referring to the trimpots in the Timing section (see GS5 near the 453
- if those adjust the pulse timings in wide range (for ex: more than +-20%)
you have no way to find out the original timings.Comment
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