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mentalDetector / Quansheng_UV-K5_PCB_R51-V1.4_PCB_Reversing_Rev._0.9

Reverse engineering of the Quansheng UV-K5 V1.4 PCB in KiCad 7
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C77 Value is 100nF #3

Open mobilinkd opened 5 months ago

mobilinkd commented 5 months ago

C77 is currently shown as 120uF. This is a 100nF 0402. Let me know if you would prefer PRs rather than filing issues.

mentalDetector commented 5 months ago

I took this capacitor value out of Ludich's and Manuel's table and did not measure it myself. 120 nF could still be a suitable value for a microphone circuit where only speech frequencies matter, makes sense. Did you measure the capacitor yourself, and if yes, how?

Creating issues is my preferred option right now, as currently already an updated working version of the schematics is available, but not hosted here yet.

mobilinkd commented 5 months ago

I removed it and measured it out of circuit using 2 different instruments (Agilent U1252B and LCR Research Pro1 Plus). At least 2 of the caps shown on the schematic as 120nF I removed and measured within 5% of 100nF. 100nF is a much more likely value for these components.

I should mention that I am using a rev 1.5 PCB. The differences are trivial. So far the only notable change I have seen is that they removed R41 and just shorted the pads of C32 on the PCB.

mentalDetector commented 4 months ago

I trust the U1252B 😃 Will close this issue when I update the schematics. I also found 100nF to be more suitable, but had to rely on work of others to save time. Please raise further issues if you find anything else to be not correct.

I assume you are behind this great work: https://github.com/mobilinkd/uv-k6-digital-mod/blob/master/UV-K6.ipynb ?

Nice to see that our HW reversing efforts are of good use and thanks for mentioning me!

jumbo5566 commented 2 weeks ago

C76 is 100nF

mentalDetector commented 2 weeks ago

Hi jumbo5566, would you mind opening a new issue for that? How did you measure C76? Could well be an error in the schematics.