DIY TGSL STEP BY STEP BUILDING AND TESTING

[chuubaba]

kt315 i connected both tx and rx coils with it but i have -6 volts instead of -5 volts. Also my tgsl was making very faint sound but then i tried to resolve the problem of sound and discovered that C1000uf was taking very long to recharge so i disturbed a 330 resistor attached with it and now it is completely silent. i can't discover what is wrong and how to fix it.

connect a coil 1-6mH value ANY COIL! to transmitter output. just then you will get the negative voltage. LOOK ON THE SCHEMATIC!!!

without the coil YOU DO NOT GET NEGATIVE VOLTAGE!!!!

[chuubaba]

the 330 resistor in audio driver circuit is very hot and there is no audio at all.

[Hyena]

the 330 resistor in audio driver circuit is very hot and there is no audio at all.
[ATTACH]43689[/ATTACH]

Fried BD140?

[chuubaba]

No. BD140 is giving good volts on its respective pin. i will recheck it again.

Fried BD140?

[dbanner]

dbanner What makes you say so on my thread?

The troll thing is now stuck in my mind.
Some of your posts are mystifying to say the least, so I am beginning to think something is weird, but hey, you just keep plugging along, hopefully you will find success. I apologize for thinking this way but the post with 100seconds/volt, really set the cat amongst the pigeons.
Good luck with the device. Just stick with schematic of the original Build document, it is 100 percent accurate.
I am sure you are good guy, so I wish you success.

[chuubaba]

I am so stuck with audio problem else i would have shown you a video of my digital multimeter. once the audio driver circuit beeps in reaction to metal hovering over the coil the C1000uf drains out and then it starts to recharge itself very slowly. It takes it approx 100 seconds to recharge 1 v in it. it seems that the audio circuit could not beep till it fully (or sufficiently) charges itself back so either there is insufficient current to keep it charged or there is bad resistor blocking flow of current to 1000uf. or it can also be a bad 1000uf capacitor

........... the post with 100seconds/volt, really set the fox amongst the pigeons.
Good luck with the device..............

[dbanner]

Seems you are on fishing expedition, jumping from part to part of circuit, going around in circles. Forget about the speaker beep or no beep.
You need to be methodical approach.
First begin with the beginning and end with the end.
1 begin with power supply, checking for correct voltages on pcb. (- +5v)
2 FOLLOWING THE BUILD DOCUMENT, check the output of U101 on scope.
Go step by step, and ask questions pertaining to each step. Don't come and say that a rat has eaten the wire on the pot.

[chuubaba]

till now got +8V from test 11 and -6v from test 13 and 0.07v from test 8

Seems you are on fishing expedition, jumping from part to part of circuit, going around in circles. Forget about the speaker beep or no beep.
You need to be methodical approach.
First begin with the beginning and end with the end.
1 begin with power supply, checking for correct voltages on pcb. (- +5v)
2 FOLLOWING THE BUILD DOCUMENT, check the output of U101 on scope.
Go step by step, and ask questions pertaining to each step. Don't come and say that a rat has eaten the wire on the pot.

[dbanner]

Remove all Chip except 4024, then connect coil to TX, check for -5volts. Do only this and report back, do not go on fishing expedition.

[chuubaba]

all chips removed except 4024. on pin 6, 5 and 9 are 3.99vDC

Remove all Chip except 4024, then connect coil to TX, check for -5volts. Do only this and report back, do not go on fishing expedition.

[chuubaba]

this is how 101.a (pin 7 of lm393 ) translates on scope.



Time/ div set at 20uS and Tx 5volts/ div and Rx .1volts/div.

Seems you are on fishing expedition, jumping from part to part of circuit, going around in circles. Forget about the speaker beep or no beep.
You need to be methodical approach.
First begin with the beginning and end with the end.
1 begin with power supply, checking for correct voltages on pcb. (- +5v)
2 FOLLOWING THE BUILD DOCUMENT, check the output of U101 on scope.
Go step by step, and ask questions pertaining to each step. Don't come and say that a rat has eaten the wire on the pot.

[dbanner]

Ok. Look on schematic, you will see at the top -5V next to C5. Now go on PCB and look where C5 is, and measure voltage at this point, with black probe connected to battery negative. You should get -5V.
Now look above on schematic you see +8V next to TR7, likewise measure on PCB.

[chuubaba]

ok. i also tried test 5 but i could not understand the results so i will look in to again tomorrow. Basically the test guide does not tell me position of Time/div and Vs/ div knobs for this test. I hope someone has any clues on this..

Standby, I'm getting my files on TGSL from laptop, give me a few minutes.

[chuubaba]

i already did this. instead of -5V i was getting -6.22 volts. The +8 volt was ok with on my board.

Ok. Look on schematic, you will see at the top -5V next to C5. Now go on PCB and look where C5 is, and measure voltage at this point, with black probe connected to battery negative. You should get -5V.
Now look above on schematic you see +8V next to TR7, likewise measure on PCB.

[chuubaba]

looks like tgsl is a thing of past thin and forgotten.i am sure kt315 and you know too much but you have other things to look into. i think my board is working reasonably but lacks audio. GTG now