Serbian "Most Wanted"

[ivconic]

Here is pcb with pot's.

Yes that's the one checked and 100% good.
I will repeat again here; for top performances is better to use LF347 and NOT TL084, 064 or 074.
Besides; use ic sockets and make compare, you will see significant differences in behavior.
SMW is tolerant towards various coils, it's only important to match TX cap with coil.
For 1mH TX coil i am using 470nF +47nF in parallel, giving 517nF.
In "original" setup 2.2-2.35mH is inductance of TX coil, than 220nF is used in parallel with it.
I guess if you try more precise and add/subtract more small capacitances; most probably you can achieve bit better performances.
Cheers!

[totob]

Hi totob, my pcb version is from ivconic, with 555 timer.
Coil parameters i can tell only for RX, cause TX is finished long time ago, inuctance is 1.03mH, resistance 3.4 ohm. Not remember how many turns and wire diameter, but somewhere between 0.45 and 0.55.
RX 175 turns, 0.25 wire, resistance 30.8 ohm, 15.09mH.
TX capacitor 480n, RX 62n.
Similiar coil parameters like Minelab Musketeer coil.

thank's CDI

[totob]

Yes that's the one checked and 100% good.
I will repeat again here; for top performances is better to use LF347 and NOT TL084, 064 or 074.
Besides; use ic sockets and make compare, you will see significant differences in behavior.
SMW is tolerant towards various coils, it's only important to match TX cap with coil.
For 1mH TX coil i am using 470nF +47nF in parallel, giving 517nF.
In "original" setup 2.2-2.35mH is inductance of TX coil, than 220nF is used in parallel with it.
I guess if you try more precise and add/subtract more small capacitances; most probably you can achieve bit better performances.
Cheers!

What i understand here is the best point of performance when Resonance Frequency of TX at 7khz?

[ivconic]

What i understand here is the best point of performance when Resonance Frequency of TX at 7khz?

It appears so.
As i recall... 7 to 7.7kHz ... sort of.

[CDI]

Hvala Ivice na pomoci.
Thank's Ivica for help.
I didn't tried to much experiment's here, this is my first smw (Serbian Cezar or Caesar).
I just tried many method's for coil wireing, and this one which i wrote work's best for me. Rock stable, exelent disc.
Also, about ic's. LF444 work's too, but like Ivconic said, the best and cheapest in this machine is LF347.
One more thing, for sens pot, serial resistor (100 - 330R) for my machine i found 200R fit the best. Sens can go near maximum, maybe 97% of pot turn before start to chatering.
Regards

[mst]

Tx 0.50 /0.97 mh/ 440nf/7.70 khz
rx 0.28/15.30 mh/10 nf (rx test NOT ac18-30-40 ac ml volt -test ferrit+cu+sil+fe+gold ....)
tx folya rx folya GND -12 volt akü (1.2ampers 12volt)

[CDI]

This module shows the VDI ...

Hi Smity, would like to ask you which connection points u used for VDI module? I guess its some pins from LF347, but better to ask before burn something.

[smity]

Hello CDI ! Connects so ...

[CDI]

Many, many thank's Smity. First i will try Arduino VDI on those connection point's.
Btw, did u tested detector on real ground/soil with this coil and what u can say about stability?

[bernte_one]

got my admiral pcb yesterday, tooks 14 days from china
made them for german diy builders

[CDI]

Look's very professional. How much cost + shiping?

[bandito]

Look's very professional. How much cost + shiping?

http://www.ebay.it/itm/232087859162?...84.m1555.l2649

[WM6]

Nice offer.

Bandito, do you know, if all boards are tested on working status as claimed (1€/40cm), or populated only?

If previously tested, which coil are used for test? Detech DD Ultimate 13" or some of other available coil?

[sinko1]

Coil for admiral can found here.
http://www.ebay.com/itm/331979817434...84.m1586.l2649

[WM6]

Coil for admiral can found here.
http://www.ebay.com/itm/331979817434?ssPageName=STRK:MESELX:IT&_trksid=p39 84.m1586.l2649

Thanks sinko1. Was your coil those used in test, with test achievement 1euro at 40cm (presumably in air test, not in real soil test)?