Originally posted by ivconic
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O.K.
I already made two G.Sabre's and two S.Sabre's so far.Wanted to know how those are working.
Also made few coils for those. Already posted some of experiences with coils.
I want to "establish" one and only good schematic and from now one to make only that.
Much experiments so far. After dozen different projects i choose Tesoro Golden Sabre to be
my favorite detector to build. Why? Simply, all real functions that prospector need on
field G.Sabre already comprehend. Discrimination is so good, it can fully discriminate
foil, iron.....what man can wish more?
Depth is great! Maybe i had luck to calculate and make quite proper coil for it, but my
experiences are so good...much better than some posted previously on this forum. Already
made few identical coils, just to check if i can make those as standard....It was not lucky
guess or coincidence, yes i got it for good!
Also noticed that G.Sabre is for real much better than S.Sabre. Greater depth even 30%.
Solution with 4024 turns to be more effective than 7660...? Why, i dont know. It seems that
all stages in device are better synchronized if dependable on main oscillator frequency.
So i rearranged schematic and cut out "notch" part, so pcb would be as smallest as possiblle.
I also rechecked schematic and previous pcb...? Except those 2 resistors(4k7) in chopper and
one missvalued capacitor(15pF) i dont see any other mistake. 4148 diode at LM393 output
("Sense" stage) is not reversed??? I think somebody claimed here that it is reversed.
I never tried to reverse it and see....Made my detectors according to posted pcb and those are
working good.
So here is Golden Sabre "light" schematic. I hope it is accurate. Checked few times....
Next step is to draw small, one-sided pcb for it....Why one-sided? I prefer one-sided pcbs.
No conditions for metalized holes in pcb's so i mostly do one-sided..
Also most of my pcb's i draw manually with thin marker.It is much easier to draw single-sided.
But there is another problem! Huge problem! Mountain problem!
I do have DXP,Eagle,ExpressPCB,SprintLayout....but still do not have enough paraxis and knowledge
to draw good pcb with those..Already learned to input schematics.But when comes to pcb i
really do not have nervs to torture myself with those software. Already tried hundred times and
at the end, my final pcb's sucks! DXP is very strange! Making its own nets and connections from
time to time. Eagle is even more stupid. ExpressPCB is simple and stupid, almost like drawing
manually....To many parameters to input and to be considered. Lost eneormous time even for
simple designs. At the end final draw is not what i wanted - not perfect.Many lacks.
That's way i decided to give up of those and let more conversant people to do the job.
I fully recomend this project to everybody interested.
No need for "high phylosophy", no need for "high tech" projects.At the end all those are very
close when comes to performances. This schematic associate all merits which one good detector
must have...
I believe there is an error in your schematic in the Ground Balance and Discriminator sections (U102a and U102b). Both R21 and R24 should be connected to the positive supply rail and not 0V. The LM393 is a comparator with an open-collector output. Note that you do have U106a and U106b connected correctly, with the outputs wire-OR'ed and tied to +5V via R41.
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