TESORO GOLDEN SABRE

[kt315]

why rx and tx don't have 20 degree phase difference??

do not run for the phase, you must run for right reaction on non-ferrous and ferrous metal moving above coil. a ferrite Carl meant is like 'earth/ground/sole' effect
you simulate on table. take a piece, not big and not small. experiment. you must not get a reaction/sound on the ferrite, being silent.

[Carl-NC]

When you are probing the RX coil signal, where are you probing? Directly on the RX coil, or at the output of the preamp?

Walt is correct, you have a good null at the 5 second mark. It doesn't really matter what the phase is at minimum null because at that point the phase is rolling around quite a bit, anywhere between 0 and 180. Once you have the null minimized, then you apply a ferrite and get the demod clock phases set properly. It's possible that if they are not set right certain targets will have a weak response.

[mostafalesnar91]

At bout 5 seconds in your video you had the coils NULLED.
Looked pretty good.

See how RX amplitude goes to minimum and the phase flips as you go through null.

When I pot the coil into the shell I leave the straight section of one coil unpotted. This is for final Fine Adjustment since the when the potting cures the coils seem to have moved.
Last coil I made had a fine adjustment nylon screw mounted to do final fine adjust which is only a small fraction of a mm.

As potting material I use an electronic grade two part epoxy with LOTS of micro-balloons added to reduce weight (about 50% by volume).

If according to you, there are 5 seconds
at the end of the movie, then why rx and tx don't have 20 degree phase difference??
Why is the sense of metals weak in this case when the coil is nulled?

[waltr]

At bout 5 seconds in your video you had the coils NULLED.
Looked pretty good.

See how RX amplitude goes to minimum and the phase flips as you go through null.

When I pot the coil into the shell I leave the straight section of one coil unpotted. This is for final Fine Adjustment since the when the potting cures the coils seem to have moved.
Last coil I made had a fine adjustment nylon screw mounted to do final fine adjust which is only a small fraction of a mm.

As potting material I use an electronic grade two part epoxy with LOTS of micro-balloons added to reduce weight (about 50% by volume).

[mostafalesnar91]

can you film o-scope screen when your move rx or tx from on side to other so i can see phase-amplitude shift somersault?
i see just one static pic you show constantly, in every your post.

please help me guys!!!!

https://m.youtube.com/watch?v=uQZhZ1S9BUo

[Op04]

Does increasing c6 from 15nf to 20nf have any effect???

Yes it does, It will change resonance frequency related to your coil inductance, if higher from 15nf then will lowering freq

[mostafalesnar91]

Does increasing c6 from 15nf to 20nf have any effect???

[mostafalesnar91]

can you film o-scope screen when your move rx or tx from on side to other so i can see phase-amplitude shift somersault?
i see just one static pic you show constantly, in every your post.

OK!!

[kt315]

can you film o-scope screen when your move rx or tx from on side to other so i can see phase-amplitude shift somersault?
i see just one static pic you show constantly, in every your post.

[Op04]

Which coil are you using? Is it on post #6142 ? From appearance that looks ok among your coil. (You can shield it later, many shield material can be use, I don't like foil and copper I use another). From that #6142 coil
1.What inductance for tx and rx, resistance value each coil?
2.Can you moving rx and tx about 2-3mm apart from that position on your photo?
3.That still movable right?? Sorry I not deep following your post.

[mostafalesnar91]

Tx ind=5.83 freq=14.46
Rx ind=6.36 freq=13.86
The shift does not happen at all, just by moving the rx, the wave amplitude shortens and lengthens. That's it

[mostafalesnar91]

thank you guys

[waltr]

Tell me something, preference with inductance or frequency
Which of these two must be correct? Why didn't you say anything about u103 lm358 pin 5? This IC is responsible for adjusting the 20 degree shift spectrum. Of course, I tried it, but this is my test results.
[ATTACH]58093[/ATTACH]
[ATTACH]58094[/ATTACH]

U103 a & b are the integrators after the sampling switches. These are AC coupled so not a good place to do null measurements.

Some people measure with scope are TX & RX coils. Here the RX signal will be very near Zero when coils are nulled. I and others measure at output of RX pre-amp, U101a. Here the signal may not be zero. All the coils I have build for the TGSL have small but non-zero at output of U101a since this amp does have a gain of about 50.
More important than zero amplitude is the 20? phase difference as described in the document you posted.
If my memory is correct I was getting 10's of mVpp at U101a-7. The TGSL works very well with these coils.

[cristiano.sar]

My friend, you are telling me how you balanced the coil, I want a complete explanation, please help me
What was the frequency and inductance of your tx?
What was the frequency and inductance of your rx? How did you null?? Tell me from beginning to end
How did you adjust the scope??
What did you set the time/div to??
How many did you set the volt/div tx and rx to??
How does this shift happen under what conditions??
No matter what I do, I can't get 20 degree phase difference through lm358 pin 5!!

I'm not good at electronics, but what I did was:
1 - Ensure TX coil oscillation is around 14.5khz
2 - Fix the TX coil firmly to the casing
3 - Put the ground balance pot at middle.
4 - Put the coils in an electric quiet place and away from the ground.
5 - Connect pin 1 of TX to channel A, at 5v/div, 20us
6 - Connect pin 7 of LF353 to channel B, at 0.1v/div, 20us
7 - Move or deform slightly the RX coil until you get the desired result

About the coils inductance I don't remember exactly but they are very near the documentation specifications.

That's more or less what worked for me.
Thanks.

[mostafalesnar91]

What was the frequency and inductance of your tx?

FIRST RULE. inductance TX under the frequency. you must get 12-14 kHz. no inductance itself for self -!! JUST for frequency.
do it.

with multimeter 14.5 but with scope up 30khz on 5v and 20us