Analysis this schematic

[mohandes]

ok dear davor
first my ampermeter and speaker dont work,why?i think because my search coil not perfect???
second when i adjustment and connect coil the adjustment impaired,why?
third discrimination not work but my coil just Sensitive to ferrous,why?
and what do you think if i use multi tern instead of potentiometer,because multitern is more Sensitive .
if you explain today again i go to college and test again.

thanks and regards

[Davor]

Try to rephrase your question in small number of simple sentences.

[mohandes]

ok thanks again
but when you think can help me solve to me please .
excuse for my english

[Davor]

Sorry, I did not understand.

[mohandes]

hi davor
can you help me about this : http://www.geotech1.com/forums/showt...ry-one)/page20
thanks
please read and answer me.

[Davor]

Just make some 300uH air coil. You can use telephone wire to make a coil.
Funny responses that you measured are most probably oscillations because your choke is somehow resonant. It rings.

[mohandes]

hi davor and carl
first i say thank you davor for your condolence, and i live in Mashhad and my city is north of iran but Earthquake in south.
second ok tomorrow again i test irf by choke 300UH is not ferrite,or check by search coil?
Carl i make search coil similar to Project stuart1.if requirement i take photo at my search coil.
3-davor i series choke by probe or i should pu it parallel?
4-why the out put have marvelous figure in #52?
please explain to me by simple language.
thanks and exuse for my english.

[Carl-NC]

It looked to me like he had the choke in series with his oscope probe.

[Davor]

Apparently he has a ferrite choke of some 350uH which most probably is saturated all the time.

Mohandes, my friend, first my condolences for the catastrophe that happened in your country. It must have been horrible.

Second, for a proper operation you must have a coil without core, a simple solenoid. Coil with core is tricky. It can saturate. Using a ferrite core in any circuit means that you understand how hard you can load it. Only a coil without core can run well in all conditions.

[Carl-NC]

I think you may be beyond your capabilities.

Do you have a search coil hooked up to the circuit?

[mohandes]

hi carl
sorry please talk to me simple.no i think davor means that,my work is wronge?
my result ?ok

[Carl-NC]

Eh, that's not what he meant. Do you have a search coil hooked up to the circuit?

[mohandes]

Hi georgi and all
in this pictures of the outputs in second pcb , X Y Z.
why the figures is marvelous?can you expalin

[mohandes]

Hi dear davor
when you say i go to collage and again measure , i put a inductor (ferriet) 350UH in the head of probe and then measure irf740.the pictures

[Davor]

you can use this wire in parallel