YOU CAN SAY TO ME THAT I CAN MANUFACTURE THE AERIAL OF FERRITΕ?

FINALLY DOES NOT KNOW NO ONE.

Hi nelson,
Take a look at the coils which can detect RF in your PDk.
If you are familiar with RF reception from a loop, you will see that the direction your PDK points is a null point.
The signals which you can receive come from the sides of the coil, not the front.
But since you are using a super sensitive detector circuit which is nearly unstable, in theory you could detect a move from null to nearly null.
But I doubt this is what is happening in your case.
My guess is you are more likely detecting noise which probably comes from man-made sources and propagates in the ground and through walls at VLF frequencies.
This kind of noise tends to follow strongly in paths which telluric currents favor, or follow underground conductors more easily such as pipes and cables.
Is it possible there are any metal pipes or cables under your house, or to the sides of where the coil is pointed?

One way to test is to put a portable oscilloscope on the loop or early stages of the receiver, and examine the signal you receive when you point the PDK at the corner of the house.
Then connect the oscilloscope to a pair of ground probes placed in the ground where you are standing, separated by 2 meters.
I am guessing you will find some kind of signal in the ground that is similar to what you receive in the receiver.
If you cannot put ground probes then you can connect a simple loop with 30 turns to your oscilloscope set to low uV scale.
When you will move the loop around the air you will find a lot of noise in your house.
I believe you will find enough noise even if you turn off all the power to your house, because neighboring houses will send noise which you can detect in your house.

But you shouldn't be testing the PDK inside your house anyway, because houses are full of electronic noises which will propagate through the air and through the ground.
The people who claim success to tune a PDK say you need to be far away from any house or power... I believe 100 meters is good enough.
Only simple power testing or spark tests are done near buildings that have electrical power.
-- Just an idea,


Best wishes,
J_P

Yes.

I THANK I WAIT FOR YOU SHOW ME YOUR IDEA.

Hi J_Player and thanks for your advice.
Yes i understand that this is probably a noise from my house.
About test with a spark i used to do sparks with my frequency generator, so this way i can pick up signals on the rigth frequency. Indeed i had done test with diferent turns from my rx coil and when i move frequency i got good spark at 40 Khz for the first coil and then the second try with lees turns on the coil gave me a good spark at 71 Khz. So i m not shure if this way of testing coils is correct, but in my case this seems to work.
This days i had not to much time to go out the city to give a try to my pdk that can by tune using capacitor, to 40 and 71 Khz.

Regards

Nelson

You already read about such ferrite antenna here:

http://www.longrangelocators.com/for...ad.php?t=18469

THIS I HAVE MADE HIM.

IN THE DRAWING THEY EXIST 3PIN OF CONNECTION.
THIS HAS TWO.

EXIST DOES PROBLEM FOR THIS?

IT NEEDS ALSO SECOND COIL OF INDUCTOR OF FERRITΕ?

FOR CO-ORDINATION OF FREQUENCY I WILL CHANGE CAPACITORS 4N7 AND 10N?

In which drawing?

PISTOL DETECTOR FERRITE SCHEMATIC (5) .
IN THE PREVIOUS PAGE

You need to know receiving frequency first to calculate Nr. of turns.

Coil in such design can be from centre to 1/4 of turns (from ground side) tapped.

You need to know receiving frequency first to calculate Nr. of turns.
WHO FREQUENCY YOU BELIEVE THAT THEY IS BEST? 5.7KHZ???


I THANK YOU FOR THE ANSWER, BUT I DID NOT UNDERSTAND WELL WHAT TO ME YOU SAID.
Coil in such design can be from centre to 1/4 of turns (from ground side) tapped



THANKS

5,7kHz can be ok. There is not guarantee that this is "gold" frequency if you wish to get right those frequency.

Frequency of your ferrite antenna depend on your tank circuit which consist of used ferrite rod, coil and capacitor.

Ferrite rod is as is, mean you take what you have in your lab stock.

Capacitor can be adapted to desired frequency. By the way, I think there is mistake in schematic: C 4,7nF need to go to ORANGE position and C 10nF to GREEN position.

Coil can be calculated to desired frequency. If you follow 5,7kHz then whole coil inductance using c 4,7nF (connected to "orange" position) have to be about 166mH.
Coil can be centre tapped. But you can try coil tapped at 1/4 of turns, count from ground side too.

How to calculate approximative number of coil turns? You need to wind about 10 test turns of wire on your ferrite rod, measure inductance, divide 166mH by measured inductance and multiply result by number of your test turns (10 or so).

Coil can be centre tapped. But you can try coil tapped at 1/4 of turns, count from ground side too.
HENCE THE SECOND INDUCTOR 41.50mH. ALL RIGHT?

AND PLACE HIM IN THE CENTER OF FIRST INDUCTOR?
IN RIGHT THE LEFT SIDE OF FIRST INDUCTOR?

WE CAN PLAY WITH THE SECOND INDUCTOR ON THE FIRST INDUCTOR. UNTIL IT COORDINATES BETTER;
I SUPPOSE.

I mean this:
50% / 50% coil taped turns
or
75% / 25% (25% is as you say 41.5mH) coil taped turns:

Coil can be calculated to desired frequency. If you follow 5,7kHz then whole coil inductance using c 4,7nF (connected to "orange" position) have to be about 166mH.

THE INDUCTOR THAT YOU PROPOSE THEY IS VERY BIG.
I HAVE 2 FERRITE 10x200mm.
I WRAPPED 10CM ON the FERRITE.
INDUCTION 15.573mH.
WE WANT 1 METER OF FERRITE IN ORDER TO WE FIND 166mH.
WHAT IT SHOULD I MAKE?
1) WRAP ALSO SECOND AND THIRD WIRE ON THE FIRST WIRE OF INDUCTOR ON THE FERRITE?

2) YOU LOOK AT THE DRAWING.
http://img98.imageshack.us/img98/602...iteantenna.png

Solution you proposed on drawing will give you very weak antenna.


Better solution is to wind multilayer coil (about 5 layers) on ferrite rod

or

to use tank capacitor bigger than 4.7nF. In this case you can use capacitor of 27nF and wind one layer on your 20cm ferrite rod with inductance of about 28.8mH.

or

instead of 4.7nF you can use C of 33nF and coil of 23,7mH.

AND IN THE THREE CASES, WE WILL HAVE THE SAME RESULT?

FIRST (Better solution is to wind multilayer coil (about 5 layers) on ferrite rod)

THEY IS BETTER?

If all of those are proper build, then you can expect better results with bigger inductance in tank circuit.

So, yes, multilayer coil can do his job better in this case.

THANK YOU VERY MUCH MY FRIEND.