TGSL prints

[Nandor]

Hi
The overlap of the 2 coils must be narrow! try to achieve in Rx as less mV as possible ~4mV is good. Shielding needs to be connected to the battery negative(ground) and all the potentiometer housings needs to be connected to the ground, it's important! If you don't connect them than your detector will go crazy when you touch the potentiometers.

[ranis]

Good morning, friends, well I'm finishing my tgsl from Mr. Ivonico, I had some problems, in the project I have seen that the bc107 was replaced by 2n2222, but it was very warm, I noticed that the bc107 pinout in the schematic is CBE, and the 2n2222a is EBC. I reversed it and managed to get -6.30v. In D6. Well I just managed to get the voltage up by reversing the voltage by reversing the TR8 position. Could someone help me with the welding of the shield, I did not get anything on it. Nandor, now detects only 10 cm, my coils were like this, tx 6.10 and Rx 6.70 mh, I was able to buy the capacimeter to measure them. Thank you.

[Nandor]

Hello Ranis.
You have to find a frequency meter, measure the freq. of the TX and you can calculate the Tx coils inductance because you will know the freq. and the capacitor which is aproximative 22nF. Use this link="http://morgoelektronika.hu/calc/lc.html". Tipe in the parameters/ C=22nF, f=(you have to measure kHz) leave the L empty! and than click "Számol". This program will calculate your coils inductance.

[ranis]

Friend, well let me know if there is a way to measure the inductance, without an oscilloscope or intutimetro, because I do not have them and I'm using aeg 28, but I know that the coil is expecial to the operation of it. Thanks in advance.
Amigo, deixe-me saber se existe uma maneira de medir a indutância, sem um osciloscópio ou intutimetro, porque não os tenho e estou usando o og 28, mas sei que a bobina é especial para a operação.Desde já, obrigado.

[Nandor]

Try to achive "minus 6 volts" aprox, the opamps need it. Thats why it detects only 5cm. Have luck

[ranis]

Good afternoon friends, well, I discovered a mistake, in the project asks for 2n2222 and I bought 2n2222a, I inverted and now I already have -3,70v, but as the inductance does not come out right, of my coils, I believe that this is the coils are With 18 and 20 resistance, but it already exits sound and detects to 5 cm. Well now is to wait until I can measure the inductance lol, Nandor hugs, thanks for the attention.

[Nandor]

Hi, the 4024 is a binary counter and divider, it divides the oscillators frequency by 32. 14.5khz/32=0.453hz so the detector will sound at 453Hz. If you change the Tx freq. the sound that the detector produces will also change.

[ranis]

Understood friend Nandor, one more doubt, to drive the 4024 the coils have to be at the correct frequency or can I make a next one to be able to test?

[ripsdevala]

Tell me how to measure Rx freq, i only know tx freq measurement and rx by using J1, how to know its already 16.1 khz by 15n?

[Nandor]

Just respect the 1.6Khz difference between the Tx and Rx coils.

[Hyena]

So as long i got best nulling its not important to get proper Freq?

Exactly, until you have god nulled coil, you can even shift frequency by replacing 22nF cap near Tx and find suitable substitution for 15nF cap for Rx and you can make it run on 12-18kHz, maybe far more... It affects geb and disc, so you always need to check ranges and modify 15nF cap, but this is really tolerant detector...

[ripsdevala]

Yes, you did. Actually it is not so important to get closest as possible with Tx to 14,5kHz. Most important (for proper null) is ratio of inductances Tx : Rx

So as long i got best nulling its not important to get proper Freq?

[Hyena]

Yes, you did. Actually it is not so important to get closest as possible with Tx to 14,5kHz. Most important (for proper null) is ratio of inductances Tx : Rx

[ripsdevala]

Hey, what is more imortant, industance or frquency? Im my build i have tx 6mh and rx 6.5mh but the tx freq is not 14.5khz, so i reduce/add the coil to get 14.5khz, rx also to get 13.9khz. Did i do right?

[Nandor]

Hi, the coils must be connected to the TGSL in order to work, the 14.5kHz oscillator drives the negative voltage supply through the 4024.