DIY TGSL STEP BY STEP BUILDING AND TESTING

[Ozoz_xba]

My frequency first was 14.6 khz and the circuit worked but i regornized that 2n2222 pins was installed incorrect and i put the pins like the open chema... after the frequency get 20khz at tx and rx and the circuit dont regornize the metal no beep coming..
Should i arrange the frequency at least 15khz at tx ?to get the metal dedector work?how to do that?

[Hyena]

What is inductance of your Tx coil and Rx coil?
What are exact values of your Tx and Rx capacitors?
What is your null?
Then continue with 101 document...
Tgsl is frequency tolerant until you keep correct Tx:Rx ratios.

[Ozoz_xba]

What is inductance of your Tx coil and Rx coil?
What are exact values of your Tx and Rx capacitors?
What is your null?
Then continue with 101 document...
Tgsl is frequency tolerant until you keep correct Tx:Rx ratios.

What is inductance of your Tx coil and Rx coil?
What are exact values of your Tx and Rx capacitors?
What is your null?
Then continue with 101 document...
Tgsl is frequency tolerant until you keep correct Tx:Rx ratios.

Tx is at 5.5mH induktance 16.8ohm (97 winding)
Rx is 107 winding (both 0.25mmwire)
On the rx is pallaral with 15nf(RXc) capasitor. I didnt pass to the nulling tests yet... i trying yo get closed rx coil to tx (without pot changes)and it dont beep at any metal...

[Hyena]

Count of windings is useless information. Measure inductance. Can you send photo of measurement both coils?

TGSL does not work without proper null. Read document and get back after you walk through all measurement points.

[Ozoz_xba]

Count of windings is useless information. Measure inductance. Can you send photo of measurement both coils?

TGSL does not work without proper null. Read document and get back after you walk through all measurement points.

My circuit works now.. it regornize the metal 1 coin in all metal mode about 15cm .on the scope my frequency on tx is 21khz...should i make another coil or how should i arrange the frequency on tx on board to get 1 couin from 25-30 cm

[kt315]

increase caps value in tx generator before you get needed 14kHz.

[Hyena]

My circuit works now.. it regornize the metal 1 coin in all metal mode about 15cm .on the scope my frequency on tx is 21khz...should i make another coil or how should i arrange the frequency on tx on board to get 1 couin from 25-30 cm

It does not matter only on Tx frequency. Its about resonant frequency of Tx and Rx. You need to measuere inductance of your Tx coil and Rx coil. If you used 220nF and 22nF capacitors in oscilator AND you measure 21kHz, I susspect that your coil have only 3mH. See? Without known inductance you can not even set your frontend. Do not change caps, just measure them precisely. Dou you have exact 220nF and 22nF? Frequency is 21.000kHz? And measure your inductance or we can calculate it roughly from these numbers if you willl measure them precisely. After correct frontend you can continue to your 30cm journey...

[kt315]

if you have 220nF and 22nF just encrease to 330nF and 33nF. do not measure nothing. the result will show you right way
and write what freq you got.

[Hyena]

if you have 220nF and 22nF just encrease to 330nF and 33nF. do not measure nothing. the result will show you right way
and write what freq you got.

If I was right, he will have 16,8kHz. To get closer he would use 470 and 47nF to get 14,06 kHz. It wont work well anyway... He need to measure inductance of both coils at first.

[Ozoz_xba]

It is 220nf and 22nf on board..the coil tx is about 17ohm 5.5mH ..yes it looks like 3mH and the frequency is about 20.9khz on tx.with 22nf and 5.5mH coil i should have 14.5khz on coil but its 20.9 .. i will jump to 33nf i see ig frequency changed tomorrow
https://ibb.co/f27BDNW
before it was 14.6 khz i saw that but some bjt 2n2222 was incorrect pin installled in board and i corrrect it,after it jumps to 20.9khz

[kt315]

you would have to get 6-6.2 mH. then you input in 12.5-14kHz needed.

[Ozoz_xba]

you would have to get 6-6.2 mH. then you input in 12.5-14kHz needed.

I will make another 2 coil tomortow then looking for mH at least tx 6mH and rx 6.5mH,it looks like for tx 6mH will have at last 110 winding at 0.25 mm wire and for rx at last 120 winding not just like in project 97winding tx and 107 winding rx...

[Hyena]

As kt315 wrote, just make rx with around 6.2mH. I used coils with 5.5 and 6.1-6.2 and they perform very the same way like 5.9 and 6.5... and this is why i nearly never count turns, depend highly on dimensions and tightenning of coil windings, so I rather check inductance and their ratio, thats the headline.
Regarfing transiator - is possible that it was in correct position before? 2n2222 are in different pinouts. Did you used tester or how you figured that it was turned?

[Ozoz_xba]

As kt315 wrote, just make rx with around 6.2mH. I used coils with 5.5 and 6.1-6.2 and they perform very the same way like 5.9 and 6.5... and this is why i nearly never count turns, depend highly on dimensions and tightenning of coil windings, so I rather check inductance and their ratio, thats the headline.
Regarfing transiator - is possible that it was in correct position before? 2n2222 are in different pinouts. Did you used tester or how you figured that it was turned?

I checked the pins and found the pins base collector emmiter,i must say that both j107 was place in wrong place(drain source,gate.) I will make tx 6.2mh and rx 6.5mh..before my 2n2907 of the oscillator was put in wrong pins. I checked and changed the pins after the oscillator circuit worked.before changing the pins of 2n2907 the oscillator circuit was not running...

[kt315]

you have to know if you put a copper into a coil then the inductivity of coil will decrease. its famous effect much people do not
understand (whole their school time was wasted on the girls) and do not want understand. so if you will measure a coil you get wrong data.
we have the table with data of manufactured coils but all that is MEASURED DATA, NOT REAL.
if you see '5.5mH' there you have to do 6mH.
it is simple rule you have to follow for VLF coil.

also, if you put ferrite core inside a coil you will get INCREASING of inductivity, you see - THAT IS MIRROR EFFECT to above with copper.