Serbian "Most Wanted"

[Max]

I have NAV also, but not using it, slow down my pc to much! I am using AVG, Kaspersky,Panda and few more..but ocassionally, not always. Whenevere i have doubts, install those,check and later uninstall...Dont like to many residents in memory...No harm done except waste of time and nervs...I do backups every 3-4 days due lot of downloads dailly...a lot of works also...
Trojan&Virus makers....they can suck my ....barrell!

Best regards!

Hi,
use AVAST antivirus... it's resident... but you can disable auto-scan HD and just concentrate on e.g. email... instant messages etc so your box will be absolutely safe from these gizmos.

It's not freeware but is worth having it ...expecially if you have a dial up connection.

To remove these "sick friends" I suggest you one of these (or more):

- AdAware
- Spybot Seek and Destroy
- HijackThis (name say everything)

BTW do you have a kind of firewall ON, right ?

Kind regards,
Max

[ivconic]

Firewall....

Thanks, i already have all those "annoying friends" software...

Firewall....Ehm! Yes,the one came with IE...Others i dont like, to many questions to answer during surfing....Annoy me even more!
Only help is frequent backuping....and work free and relaxed...
Anyway thanks!
I am using AdAware SE for longer period......."Alexa....Alexa....Alexa.."
Nothing but damn "Alexa"!?

Best regards!

[J_Player]

Hi Ivconic,

If you have Alexa toolbar, you need to remove it. This is a BHO which sucks up yout surfing bandwidth and runs programs in the background to slow down your computer. It uses your processor to make files during startup and when surfing, then sends reports with much information about your system to remote servers. All this uses up some of your system power that can result in very slow surfing for dial-up. Even if you remove the Alexa toolbar, sometimes the BHO programs are still running with the toolbar gone.

One way to keep your browsing fast is to use Firefox or Opera browser. Alexa does not run with these. If you want to remove Alexa, you can google to find "remove alexa" and you will find many methods to do this.

Majorgeeks usually has most of the tools you need to keep your PC happy: http://www.majorgeeks.com/Alexa_Tool...ool_d4433.html

But the last time I had a BHO problem with Internet Explorer, the removal tools did not remove all traces of it, and it kept returning. I used Registrar Lite to search every connected file and folder from the registry and manually delete them. Then when the files and folders were gone, I manually deleted all the registry keys related to the BHO. To remove Alexis, files and folders, this must be done after re-booting your PC without opening Internet Explorer. Don't edit your registry unless you make a backup and you know what you are doing. Otherwise you could ruin your windows installation.

Best wishes,
J_P

[ivconic]

It's been a while, since i posted this...
This "serbian most wanted" actually was and still is most controversial diy project here in Serbia. Many beginners usually do start building detectors with this one. Few of older enthusiasts already made a series and spread good and bad opinion among prospectors - usually dependable of quality of those hand mades.
I met few handmades made by others so far. It is truth; some of those work very good and some don't. Until recently i never payed more serious attention on this one. But recently i decided to investigate this more and also made my first "Caesar" !
Yes it is working very descently! Of course most of working quality depends directly on coil. So i used one older Fisher coil just to experimenting. It is quite a effort to adjust good phase , yet once done; this device is working very,very good.
So far nobody ever offered accurate schematic. I already posted one and only schematic which circles arround the net, and it is faked and not accurate at all.
So i decided firstly to trace already made and workable device and to establish most proper and most accurate schematic.
Now...looking at this schematic, it is so obvious that this detector is a sort of sublimate between White's, Fisher 1225 and Tesoro. Although we can meet simillar or exact the same stages in other projects too.
Also, recently, i discovered another fact; originally, this design came from Bulgaria. I guess some good bulgarian enthusiast payed a lot of effort to experiment and finally got this project.
Looking at schematic..man can be fooled by it's simplicity and wrongly to conclude about it's performances.
I took it outdoor with me few times and was pretty amazed with it's performances and depths i reached.
Only one minor drawback is; it can suffer from minor instabillities if Sensitivity is adjusted to maximum. Lowering Sense device becomes very stabille and loose just a bit of depth.
Discrimination is not so splendid as on TGS/TGSL/Eldorado ..but it is still very good and useable.

When making handmade coil, datas from first (faked) schematic can be used. Those datas are good. Wire and numbers of windings are related for standard 27cm DD coil..(255x137mm for "D" shape)...

So...what else? Aha..! Those quadro opamps are not LM324's by demand. TL064-TL084's can be used. And even better 27m4 or simillar...

What else..? Here it is and enjoy! I suggest you to make it and see..worth of every effort!
Cheers!


P.S.
Oh yes! One more thing; drawing schematic i omitted battery testing circuit. So you can be confused (dont be) comparing pcb and schematic. I also skipped those few components on my detector. Simply i dont like it...and dont need it..

[ivconic]

Oh yes; just spotted one mistake! At 555 pins 2. and 6. must NOT be connected to pin 8.
I guess software (ExpressPCB) made wrong connectione there!? Or it was me? However, pins 2. and 6. are connected togather but not with pin 8.

[ivconic]

Ok..using same approach i changed concept a bit. Also corrected few minor mistakes on previous schematic. Now is time to draw another and better pcb...

[porkluvr]

Hello Ivconic! There is nothing wrong with what you are showing but here's a way to use less power at your speaker by adding two diodes and one resistor.

This mod allows separate control over audio frequency and Duty Cycle. The two adjustments are not completly non-interactive but pretty much. (Hmmm... changing DC affects frequency according to the formula Fo=1/(Thigh+Tlow)?) For somebody who doesn't want a square wave audio output (because of making too much noise or using too much battery power) variable DC would be desirable.
Just make sure you don't reverse the diodes by mistake or you will have something like 95% DC instead of approximately 5% as shown here. You wouldn't hear any better and your battery life would suffer.

Just like your circuit, 1/2 LM358 could be used. It should make slightly lower output frequency.

Increase the value of the DC resistor if you need more volume. Don't go too high or you defeat the purpose.

[ivconic]

Thanks Porkluvr!
This is very interesting new little thing to learn! I will include it on pcb for sure.

[porkluvr]

oops

I made a mistake (again?!! ).

I got to looking at the audio output. When I apply what would be a "target good" input from the comparators; operating the entire subsystem
instead of just looking at the oscillator output - what occurs is the not what is desired.
Two reasons.

Change two things. Reverse the diodes (also change the resistor values to obtain the same approximate frequency as before). My fault.
I did not look at the entire audio system. Duty Cycle gets inverted in the audio transistor chain. That was my bad.

But this is not my fault: I believe you should swap the connections of V- and ground between the emitter of Q8, and R47. (This assumes that
the output of U6A goes positive with a good target, right?) You won't have a smooth
transition from no audio to full audio as target signal level increases without swapping those connections.

note: Compared to my previous post, I turned the speaker resistor around, so the "I(Rspk)" display goes positive instead of negative.
That's just a little spice oddity. I hope it doesn't add any more confusion.

Maybe it's right this time.

[porkluvr]

I thought this project would be easy and I might try and put on Eagle lite 3X4 board.

So, I determined that Rx coil would be 2.4mH instead of 2.4uH. Pulling out a coil calculators and working backwards, it came up with about 165mm for coil diameter, estimated.

But none of this matters because according to LTspice, the TX oscillator does not want to oscillate, and I'm not going to try and force it... .

[Fred]

Thanks for infor ivconic

[getsa]

Hi Ivconic,
Why in your sheme solution you built the Rx preamp amplifier with few transistors instead the preamp with transistor connected as a common base amplifier?What are the advantages/disadvantages? Would you explain,what is your opinion?
Best regards

[ivconic]

RX was taken from Fisher 1236 and TX from White's Classic. This is not my own project. I just made 2 devices according to this datas.
About coil; suggested datas are 75 windings, 0.4mm wire for TX and 160-170 windings, 0.2mm wire. DD coil 28cm diammeter. 255x137mm for one "D".
But i couldn't obtain such wire. I had 0.35mm and 0.25mm. So i made 75wind. 0.35mm and 173 wind. 0.25mm. Coil is working very good. For example; 1e coin detects at 34cm in air.
Phase is easy to adjust. Easilly rejects ferrite rod. Very good stabillity on soil. Wirements in search head are different than at TGSL. Al faraday cages are wired togather, but goes separatelly through cable, and are conected to cable shield. TX and RX leads also goes separatelly. So 4 leads cable with common shield is proper for this setup.

[getsa]

Cezar

Hi Ivconic,
How is the diskrimination? Is it the same through the whole lenght of the active zone? If it diskriminate correctly between 15-34sm,or begin to mix fer/non-fer.? Ibuilt almost selfsame shematic like cezar,and achieve the results just like yours,but in my case,increasing the lenght by the ferrous target,the detector begin react wrong(well,not too much,but...).

[ivconic]

Yes it is true. Same thing with all Cesar detectors i have been seen so far, no matter who made it or which version was made. It suffers from what you just explained.
But than again...majority of other brands and models i tested so far acting pretty simillar also.