Analysis this schematic

[Davor]

Sorry, I did not understand.

[mohandes]

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

[Davor]

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

[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

[georgi.g.zhelev]

[QUOTE=mohandes;170678]ok thanks again
but when you think can help me solve to me please .
excuse for my english[/QUOTO

OSCILOSCOP : 1. ITENZITY....... poz. > minimum .
2. TIME/ DIV...... poz. > 50 мks
3.Use the oscilloscope probe x 1 x 10 !!!!
4 .Coil ..........350.....500 мкH r= 0.7ohm.....1,2ohm! diametr.....20cm ...30cm ;
5. Show photo: NE 5534 (LF 357) .... piin 6 .....
6. SEE #41 ,there's everything you need to do Puls Star -g ,SEE oscilosgrams !!!!!
7.Check the voltage of power supply , ( Battery > minimum 14...17v !!

[georgi.g.zhelev]

Use the oscilloscope probe x 1 x 10 !!!! All brands osciloscope probe 20мHz.....100мHz.

[Davor]

Georgi explained the most of your questions

first my ampermeter and speaker dont work,why?

Most of the digital instruments are designed for measurements of voltage or current at frequencies below 100Hz. They are comparing voltage with a ramp, so measuring anything faster than 100Hz will not work. Old analogue instruments with dial will show you average value, but digital ones only if you are very lucky.

For that reason you must become friendly with oscilloscope. It shows everything.

[mohandes]

[QUOTE=georgi.g.zhelev;170706]

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

OSCILOSCOP : 1. ITENZITY....... poz. > minimum .
2. TIME/ DIV...... poz. > 50 мks
3.Use the oscilloscope probe x 1 x 10 !!!!
4 .Coil ..........350.....500 мкH r= 0.7ohm.....1,2ohm! diametr.....20cm ...30cm ;
5. Show photo: NE 5534 (LF 357) .... piin 6 .....
6. SEE #41 ,there's everything you need to do Puls Star -g ,SEE oscilosgrams !!!!!
7.Check the voltage of power supply , ( Battery > minimum 14...17v !!

Hi daer georgi
i read all 20 pages of ps g detector several times and write every think i need ,thank you.
but befor you say i again go collage and test my pcb With search coil.
this is amazing becuase i test it befor and good work but today not well.
1-i set pin2 555 in 8.33ms for duty (T) or 120hz.next i set pin3 555 on 150Us (pulse width)
2-i check pin9,10 4053 was and good.BUT pin6 4053 have a problem(i put the picture).and pin11 4053 have Terrible out put(like Modulation & i put this picture)
3-set pin6 first4538 (but i set the duty cycle by multi tern relate to Delay,why ?) and pin 10 second4538 was good.
4-It is emportant set but i have bad figure in osope for ne5534 in pin 3 and pin6 whether Without coil and With coil.i put the mlti turn on 27k and when i measure pin6 the value not -0.2volt,how i adjust that.?
5- It was interesting when i set the second pcb i Effort to set the third pcb(TP points you say georgi to alexsis)but dont work adjustment on this,why?
and...
iam not Tired soon.
exuse for my english
i wait to your help my friend davor and georgi

[Davor]

Did you check if damping resistor is OK?

Usually when things stop working it is something simple to look after.

[mohandes]

[mohandes]

explain for above:
first picture and twain end piture is for pin2 555.
second and third picture for pin3 555.
forth picture for pin9 4053

[mohandes]

[mohandes]

explain fpr abov epictures,attention No connection coils:
first and final picture for pin10 second 4538
scond for pin6 4053
third and Fourth ,pin11 4053
and fifth picture pin6 ne5534

[mohandes]

[mohandes]

when i connet the coil and again measure
first picturepin3 ne5534
second picture pin6 4053
third anf fourth and fifth pictures for pin6 ne5534
final for pin10 4538(volt/div=50mv and tim/div=50Us)