Question about tgsl

[Nandor]

Thats the main problem with Silverdog pcb's. The holes are metalized also, removing components is very hard.

[Qiaozhi]

Thats the main problem with Silverdog pcb's. The holes are metalized also, removing components is very hard.

Silverdog's PCBs are double-sided, and therefore they have plated-through holes, which is quite normal. You would not want a double-sided board without plated-through holes, as you would need to solder both sides of the board for every component.

Anyway, populating the whole board, on a design you've never built before, is a recipe for disaster. The correct method is to build in stages, checking each stage as you go along.

[kt315]

checking each op amp and 393 on any stage being before soldering and being in a process of troubleshoting - tester board is helping you.
i ordered them much so they cover all your needs. sorry for reminder but i can not see on your long torments of creativity without tears .
recently i was checked easely 5218A in a board of 2+1 amplifier. just desoldered them and put in the tester.

[waltr]

Unfortunately I didn't use sockets :/, maybe should I start removing them from right to left, like for example I'll remove first IC from the right and then turn on the device and see if the sound is gone?,because it is hard to remove them all together:/

Ok. Then before removing all the ICs, Just do the measurements I outlined in above post.
1- Oscillator running?
2- charge pump outputting -5?
3- etc.

[waleed]

Thank you all for the support I appreciated it, and oki waltr I'll do these tests at sunday when I go to the uni because I don't have oscilloscope and I use the one at my uni, I'll be back when I'm done.

[waltr]

Thank you all for the support I appreciated it, and oki waltr I'll do these tests at sunday when I go to the uni because I don't have oscilloscope and I use the one at my uni, I'll be back when I'm done.

Good. I'll be watching for your results.

[waleed]

Waltr, before the test part,can you take a deep look on my board and see if I did anything wrong, and also check if I did the mod by silverdog right or not, what I did is removing R33 and I put diodes at C20 and C23 reversed from D10 and D11, R29 and R31 was already 1meg on the board.

https://i.ibb.co/xq4k2nL/IMG-20200214-WA0005.jpg
https://i.ibb.co/LhG98VW/IMG-20200214-WA0006.jpg
https://i.ibb.co/PGDtMHv/IMG-20200214-WA0007.jpg
https://i.ibb.co/MCVvyzz/IMG-20200214-WA0000.jpg

[Nandor]

Hi Waleed

The potetiometers you use must be linear not logarithmic.

B100k-linear and A100k-logarithmic.

[waltr]

Waltr, before the test part,can you take a deep look on my board and see if I did anything wrong, and also check if I did the mod by silverdog right or not, what I did is removing R33 and I put diodes at C20 and C23 reversed from D10 and D11, R29 and R31 was already 1meg on the board.

Mod seems ok. I played with that mod and found it didn't do much to improve performance.
There are a few things you can check using a DVM.
1- Is there -5V (-6.2V)?? A TX coil MUST be connected to have the TX Oscillator run which is used for the charge pump.
Without -5V the circuit will not work.
I would disconnect the speaker so the noise does not drive you crazy. Also some speakers may not work causing problems in the rest of the circuit.

2- Voltage at the outputs of U104 & U105 need to be very close to Zero. It is these outputs that trip the comparator, U106, to cause output to speaker.
3- Check Voltage at inverting inputs of U106. The Voltage here should change when you turn the Sens. pot.

Check the POTS as Nandor stated. Log pots will kinda work but they really should be linear pots.

[waleed]

Hi Waleed

The potetiometers you use must be linear not logarithmic.

B100k-linear and A100k-logarithmic.

Hi Nandor,you mean the black potentiometers I used is a logarithmic ones and how they would affect the circuit, but I don't think they cause the continues beeping because I used them on my old board and it worked but the performance wasn't good and that's why I changed to the EDU one.

[waleed]

Mod seems ok. I played with that mod and found it didn't do much to improve performance.
There are a few things you can check using a DVM.
1- Is there -5V (-6.2V)?? A TX coil MUST be connected to have the TX Oscillator run which is used for the charge pump.
Without -5V the circuit will not work.
I would disconnect the speaker so the noise does not drive you crazy. Also some speakers may not work causing problems in the rest of the circuit.

2- Voltage at the outputs of U104 & U105 need to be very close to Zero. It is these outputs that trip the comparator, U106, to cause output to speaker.
3- Check Voltage at inverting inputs of U106. The Voltage here should change when you turn the Sens. pot.

Check the POTS as Nandor stated. Log pots will kinda work but they really should be linear pots.

Thank you waltr, I understand now what to do first, I'll provide feedback when I'm done.

[waleed]

And yes all my potentiometers ends with A letter, look at the image below you mean like this one right?

https://i.ibb.co/p2RfMnV/20200214-161536.jpg

[Nandor]

Hi
Yes you need B version. The difference is the resistance over distance, I hope you understand. Listen if you have a 100kB linear pot at middle position it will have 50k because its half of 100k, but if you use logarithmic 100kA at half position you will have maybe 20-30k and the rest of 70k is on that other half because this type is for volume control not for level control! Very important difference. Now you need level control for Disc Geb and Sens, so you can properly adjust the detector.

[waleed]

Hi
Yes you need B version. The difference is the resistance over distance, I hope you understand. Listen if you have a 100kB linear pot at middle position it will have 50k because its half of 100k, but if you use logarithmic 100kA at half position you will have maybe 20-30k and the rest of 70k is on that other half because this type is for volume control not for level control! Very important difference. Now you need level control for Disc Geb and Sens, so you can properly adjust the detector.

Thank you for the explanation I'll change them to the linear ones and then I'll do the tests that waltr mentioned above..

[waleed]

Waltr I bought an multimeter today, well I measured the regulator output it was 7.9v it is ok, and then I measured the charge pump before I connect the TX coil it was 0.7 volt and after I connected the TX coil while it beeping the voltage also was the same (0.7v), it didn't change to -5v or so, well now we know where to start solving problems, and tomorrow at uni I'll check the TX frequency and I'll see the waveform, but for now why I didn't get the -5v when I connected the TX coil?, it is possible the problem with the 4024 ic? Because I took it from my old board it's not a new one or maybe the transistors is reversed?, but I'm sure I placed them as the datasheet.