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Diy optical pickup for guitar -- is it possible?

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BillTodd:
For analogue audio work a 20MHz bandwidth 'scope is plenty. You don't need serial format converters or logic analysis functions.

If you are going to blow serious money on a new one, then buy the best most highly featured one you can afford.

If you just want something to debug your pickup then buy something cheap and cheerful , it will always be useful even if you buy something better.

Beware of the youtube reviews, They don't spend their own money and, like Dave's review yesterday, will compare a 70 currency unit ($£€) device with one costing 12000.

Seek out other purchasers/users of the device on forums and ask their opinions.  BTW that little scope wasn't too bad, but I felt it was still too expensive , at 40 cu it would have been a good buy .(you have to be cautious about the results of any instruments when working near their limits)

If you don't already have one, get yourself a copy of 'the art of electronics' by Horowitz and Hill .  I think it will fill a few gaps in your knowledge.and is always useful as a reference.

sorveltaja:
I tend to take Youtube reviews with a grain of salt.

Before purchasing something bigger, I have a habit to read different forums, as it's possible to get more unbiased, and wider picture, considering the brand(s), and possible problems/solutions involved.

The book you mentioned seems to have more approachable way(at least for me) to explain electronics. When looking at table of contents https://artofelectronics.net/the-book/table-of-contents/, there is some pretty interesting stuff. Thanks for suggestion.



 

WeldingRod:
The Art of Electronics is a seriously great book, and I enjoyed reading it, um, many, years ago!

Sent from my SAMSUNG-SM-G891A using Tapatalk

sorveltaja:
I think I found at least one reason, why the previously mentioned zero crossing detector didn't give any output, even when signal from the receiver was amplified.

The signal exists, but it seems to 'float' about 780mV above the zero volt point. Maybe not the most scientific way to measure that, but the result is there:
 

Could the reason for the signal floating above(or below) zero be something like a voltage offset?

I have a very shady understanding about how logic level output can be treated with pull-up, or pull-down resistor, to bring the 0's and 1's to the acceptable 0 to 5 volt 'window'.

Does that apply to analog signals at all?

But questions aside. The square wave generator, that I used to feed the IR-led, or sender, was again based on the 555-timer -IC(I should probably have a screen shot of it's output too).
After all, the output is square wave, when compared to the receiver's one.

No matter how many different versions I've tried out, all of them suffer 'duty cycle vs frequency' dependencies. When one is changed, other changes also.

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One might guess already, where this leads. Now, that I have a multimeter with a colour screen, I'm obliged to have a proper function generator .

I have looked for something simple, like Velleman's HPG1MK2, which has 1MHz range. But after looking for it's specs, it doesn't seem to have any kind of duty cycle control for the square waves.

I'm aware, that Ebay offers a lot of 'authentic', old hardware, but I'm not so sure about them.

 

Sea.dog:
You may need an additional amplification stage before the signal is applied to the detector.

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