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Hi,Ivconic!Can you post here lay file for the first pcb - with LM555?
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Hi,
Ivconic you have RH coil.
Have you try it with SMW?
What should be the caps for this coil?
Because cant tune it no matter what I try.With 470n/68n get average performance.I try 520n/33n.
Have change those caps all night and the only way that I can get some performance is with 68n/10n.But then cant adjust GEB.With those caps it detect 1e coin about 35cm.And I should be able to get this around 40+.And in same time should be able to adjust geb.
Now I change 084 with LF347.Device is more quiet.
ThanksComment
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Originally posted by Ultimate_Haze View Post
Be sure that you wired coil properly. 1mH goes to TX; signal to signal and shield to pcb minus. 15mH goes to RX; signal to signal and shield to pcb GND (not minus).
R12 200 ohms trimmer adjust to 40-60 ohms between BC327 E and plus or scope BC327 collector and adjust for best sinus.
LF347 is much better than TL084.
R21 (10K) to middle position for a start. R29 (10K) to 1/3 (SMW can not fully reject ferrite rod if R29 Disc is at minimum). Than adjust R16 to reject ferrite rod 5cm away from coil surface.
SMW is detector much different than TGSL, can't fully reject ferrite rod if Disc is at minimum. Disc pot is crucial here. Always keep it least to 1/3 and higher. At "3" it must fully reject ferrite, at "6" must reject common iron pieces.
If you lowered Disc to minimum than it is normal to accept ferrite, normal for this particular handmade.
White's Classic I,II and III are also acting simillar. That's why those do have "Black sand" feature and extra resistor included in circuitry by use of switch.
Same thing can be done here. I did not put it on schematic. It is a matter of experimenting. If you want Disc pot at minimum AND to fully reject ferrite than look Classic schematic (how is done there) and apply same thing on SMW. You will have to experiment a bit to find proper resistor.
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Refering coil...try caps from 0.47 to 0.68
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Cheers!
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"...Same thing can be done here. I did not put it on schematic. ..."
There are some types of so "soft" soils where is desireable to search with a bit more "unleashed" phase at detector, so as i noticed.
Doing this way you can locate much deeper items than usuall (it is advisable to search without Disc at some terrains to locate extremly deep items).
That's why i didn't included extra resistance in serie with Disc pot to provide full ferrie rejection at minimal Disc preset.
OK, i could use extra switch than, but i simply didn't cose wanted to keep design as simple as possible and less commands on front panel too.Comment
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Hi,
Thank you.
I will do as you say.
No I dont want fully reject ferrite rod.Just wanna make it work like it should.
I have connected coil the way you describe.
But haven't try more than 520n for TX.
Funny but I can get good detection only with 68n for TX.
I will play with those caps some more.
Have you try to connect this RH coil?And test the performance?What should be expected for 1e coin?
It looks like this is great detector.
Can wait to tune it and see it in action.
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68n at TX !??? Hard for me to imagine that!? Are you sure you didn't reversed TX an d RX ? Because 68n at TX does not makes a sence at all...?!?Originally posted by Ultimate_Haze View PostHi,
Thank you.
I will do as you say.
No I dont want fully reject ferrite rod.Just wanna make it work like it should.
I have connected coil the way you describe.
But haven't try more than 520n for TX.
Funny but I can get good detection only with 68n for TX.
I will play with those caps some more.
Have you try to connect this RH coil?And test the performance?What should be expected for 1e coin?
It looks like this is great detector.
Can wait to tune it and see it in action.
No i don't have RH coil anymore, sold it last summer. I have only Excellerators and 25cm TS1000 coil for Musketeer...
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Although inductances are same at coils for RH and Musketeer....maybe something else is much different? I really can't tell what could be the problem.
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Hi,
Yes its too strange.
Pity that you dont have this coil any more.You would see what I mean.
Maybe there is something inside this coil.But it should work on 7kHz for shore.
So I will try to make my own coil and see if can make it work ok.Comment
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Here is photo of one finished SMW. This one is with handmade coil...
I used TGSL front panel for it, beacuse i haven't prepared panels for SMW yet...
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Good!
Can you make one video showing detection of 1e coin.So we can hear how this work.Might be useful.
What should be the value for R20 with 1mH/15mH coil?1K8 or 3K9?
Thank you.Comment
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I can but not now. My digital camera is not recording tone!Originally posted by Ultimate_Haze View Post
It is old and obsolete. I must wait one friend to visit me with his camera and we will record the video than (he recorded TGSL testing for youtube with that camera). It will be in next few weeks, i guess..
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Originally posted by Magma View Post
Hi Magma.
I have a discrimination problem, so if you can help me.
My Disc potentiometer rejects the "no ferrous" objects but not the iron. So with potentiometer full closed i receive a gold or a silver coin very easy, but detects and iron. If i will turn it right then i detect the iron good again but not the gold or silver.
I attach a photo of the out pin1 of LM393 (Geb), one photo od the out pin7 of LM393 (Disk) comparing to Tx signal and oe photo between pin1 and pin7 (Geb - Disc).
I forgot to tell you that i reversed the coil wires without results
I wait your opinion
Regards
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