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Si eu vorbesc Limba Romana:P
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the scheme created by Eduardo did not see metals and non-metals switch all channels.Comment
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I think this is an error of pcb is true?Comment
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PCB created in me C1 is between pin 10 and pin 9Comment
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Hello Eduardo
Thank you for sharing this work.
I'm looking at the scheme by the GS6 You and I would like to make some comments based on the GS4, as some differences that could influence the final project performance is observed.
In the GS4, both channels are identical, so I believe that the resistance marked "R" must be equal to "470 K". In the scheme published by you, in the lower channel Figure 10 K.
It could also be higher such as 1 M, but both should be equal.
The time base for both channels should be equal but displaced some time in the channel iron (the channel is above), this is adjustable with RV8 and good, but for the scheme, the marked resistance as R20, should be of 240K to be identical to the lower channel.
Furthermore, the terminals should be reversed "U3a 2 and 3", because both channels, handling the same signal polarity.
It should also provide for a reversing switch for the detector to operate in the "all metal" mode, since the present configuration is the discrimination mode, or "SELECT 1", in the GS4. In this way, the throughput decreases.
There are other changes that could be made to optimize performance, but I think we first have to build the detector and check its operation.
A little work is necessary for ultimate success.
Regards.
Jose.Comment
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Here ?In the GS4, both channels are identical, so I believe that the resistance marked "R" must be equal to "470 K".Comment
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Hi all,
I could have sworn I posted links from other GS4 threads that could be relevant, somewhere earlier in this thread. Alexismex produced/published the first schematic (GSIV). Originally there were no resistors at those two points. It changes the original character of the detector.......it can be a motion or a non motion machine. It was Reg that suggested the addition, simply to make potential drift less of a problem. Then a 2007 schematic in a different format is posted and the error in the value of one (10K) of those two resistors is introduced.... It is then carried over by people not paying attention...
(It is also interesting to read Maxs comments on his build all those years ago. He built as per the original, without resistors. http://www.geotech1.com/forums/showt...5744#post75744
Whilst he did experience drift, it was not bad at all. Read his post.)
Orbit has done a great job sharing his version. He has replaced the fets used as integrator switches with cmos switches (4066). (Even Foster recommends them for modern designs - see his comments in his jpeg here : http://www.geotech1.com/forums/showt...354#post171354 )
Instead of going back to old schematics and trying to implement Orbits changes, perhaps follow Joses suggestions above. Use Orbits schematic. Build. See whats going on. And maybe later, look at bringing back the conductivity switch options. Ditto for switchable motion/non-motion option. If it tickles your fancy.
Just stick to getting Orbits mainboard working.Comment
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I replaced front just because drift and instabilities because I noticed that gs4 has some problems so that these resistors not necessary if detector static not moving,a is lost, and on the get detector was tried in real-time works perfectly .Comment
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gives us great trouble ... I do not discriminate project and R20 replaced with 240k and change nimik RV8 but we used only quality parts but nimik. Does anyone else have another idea. Thank youComment
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Hello 6666
If that meant to me ...
If I were to arm the "GS6" Eduardo version, first install the two resistors of 470K. Not affect the operation of the team, by contrast, it is more stable.
Then you have time to try other values, or remove them.
JoseComment
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Hello Luci1988Originally posted by luci1988 View Post
Excuse my bad English.
RV8 nothing to change.
RV8, okay.
Try testing the detector stages.
First check the operation of the lower channel.
To do this, cut the wire between RV3, and leg 4 of U5D.
It must function as a common detector, without discrimination.
JosephComment
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Thanks for the advice Jose.Comment
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Hello Jose
my drawing was only to show the two resistors that you mentioned in your post.
Would it be possible for you to show us how you wired the GS4 switches for ALL METAL ?, thanks
From Google translate English to Spanish
Hola Jose
mi dibujo era sólo para mostrar las dos resistencias que usted ha mencionado en su puesto.
¿Sería posible que nos muestran cómo se atan con alambre los interruptores GS4 para TODOS METAL?, GraciasComment
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GS-6 Corrected.Comment
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