SNIFFER XR-71

[Geo]

Ok i measured the R22. It is 330R. When i will have free time maybe to replace it with a 390R.
Bye

[mohi]

hi aban
please send me digrame . shametic and list to my e:mail([email protected])
thanks
mohi

[Unregistered]

hi aban
please send me diagram and shametec of pulse star 2
thanks for you
mohi
e:[email protected]

[amtech2005]

SNIFFER XR-71

Hello Mohi , The Pulse Star schematics have never been posted here !! . Aban the forum member who built a copy of this has not been on in 2 years, unless he is under another name.I have been on this forum since october 2001. So for a number of reasons we have had some great technician / Members disappear over the years . Sad, But it's a part of life. Anyway here is a zip-file of everything I have , which is already posted over the threads. Do you notice that Pulse-Star 2 has 2 pic Chips ?? The programed "Pics" Are used for "potential" Discrimination. Sorry, these files are all I have for now.............Eugene

[mohi]

dear sniffer xr-71
the pulse star.zip did,t opend please try agin many thank,s for you or sen it to my mail
[email protected]
mohi

[amtech2005]

SNIFFER XR-71

Hello Mohi , Remember the file does not contain a Schematic !! Just a bunch of images . Anyway in the circuit there are 2 "pic-chips" 16C71's and I think there is 1 "pic-chip" used per channel . One for Ferrous and one is for Non-Ferrous in an attempt for accurate discrimination !!!!!!! So if you do find a Schematic you will have to write a Basic-Pic-program for each. If your e-mail address is correct I will send this zip-file. Best of luck on this "Detector Project" There are a few other circuits posted on the web, like this one. But you just have to search for it. .....Eugene

[Unregistered]

dear sinffer xr-71
i need all list schametec and program please I don,t forcet that
my mail
[email protected]
[email protected]
thank you

[1843]

To Max


Is increasing the R3 necessary when increasing the R1 ?

Thanks,
1843

[Max]

uhm...maybe I understand reason for this question...

[ATTACH]5740[/ATTACH]
Is increasing the R3 necessary when increasing the R1 ?

Thanks,
1843

Hi,
there are other parts connected... like inverting input resistor you didn't draw.

In differential configurations you must mantain simmetry of the two halves to get the differentiation on common mode noise: it's a benefit to you.

So, if you change one , you need to change the other as well.

Both, opening or not the switch, you get a polarization voltage at the lower 120K, thus providing the effect of a battery there used to fix an offset, required for proper operations of preamp far from saturation.

In both cases you actually don't need, to simplify, both resistors to be 120K, they could be also different values. But if the scope is mantaining hi immunity to common mode noise... well... it's strongly suggested you keep them same value there.

This way, the simmetry give you always A(V2-V1), V2 is at + lead, V1 is at - lead and A is the voltage gain...(in your case is 120/1=120 times)... that means a common mode noise will have two amplified components in phase opposition and will be virtually eliminated from signal at output.

This is no matter of which signals you put at inputs, if they are compatible with linear behaviour of the amplifier.

So, though not strictly required for signal amplification it's good you keep simmetry to gain the maximum common mode noise reduction.

Without this your preamp will work too, and you'll not notice big differences there... but cause PIs have enormous amplification along the chain you'll get sooner or later that dang noise propagate being amplified and then create big troubles.

Kind regards,
Max

[amtech2005]

SNIFFER XR-71

I found this with a date of Nov.2006 . For Sniffer XR-71?...If it helps someone , than this is Great !! If someone remembers this , let me know.....Maybe from Russian site ???......Eugene

[aft_72005]

Hi amtech 2005
This file for first time uploaded by KT315 in geotech forum ,
If you search “sniffer “maybe you can find that thread,
As I remember in that thread also MAX said, he had single side
Sniffer PCB and promised to person that gave it to him.
Best regards.

[kt315]

amtech,
I will discovery you this great secret now. XR-71 was done by Gueorgui Gueorguiev in Bulgaria. he released Delta Pulse too! so I would like to ask you WHERE IS THIS BULGARIA? why you think Bulgaria is a state of USSR? what NATIVE is in Bulgaria? may be Turkish or Albanian is native? what the h to say all were done by russians. we must ask him to Welcome in the forum and I hope he will give you ALL info you wish of.

[amtech2005]

SNIFFER XR-71

KT315 , I think this "Bulgarian File" come from a .RU Web-Site .But Now I am not sure ! I just rememember getting lot's of information from Bratsk-city .ru in late 2006. But I noticed that some good metal detector .ru sights are not working anymore!!!! But this file could be made in Bulgaria then sent all over the web!!! I will be more carefull about where I say I get my files. You are right , and this is important to know , especially if there are errors !!! I do not want to blame the wrong people for making mistakes ............Have a Good day !!!........Eugene

[kt315]

I still see his posting in net. there he writes about his Magnum updates. yes, he was been active in 'bratsk city forum' time (the site was moderated by Roman Gusev aka silver goose). first schematics of DP and XR-71 was got from Gueorgui for the site. what he does and where he is now I do not know.

[1843]

Hi kt315,
Have you read the following page? There are some information of Gueorgui Gueorguiev...
http://geotech.thunting.com/cgi-bin/...n/guestbook.pl

Best regards
1843