开云体育

It does. Accuracy!

Conn tried to develop a device for tuning musical instruments - could have been over 50 years ago. It used multivibrators as oscillators and a magic eye - 6E5, as I recall - for indicating when the sound picked up by the microphone matched that of the multivibrator. The idea was brilliant because the human eye can detect slow flicker far better than the ear. The multivibrator was a valve job that drifted as the device warmed up. So, you had to tune up quickly; it was really only good for single-note instruments like the brass and woodwind families. You could use it for the string families if you tuned one string and then relied on fretting and your ear to tune the other strings; however, I have seen fretted guitars whose fretting is way out, just by visual inspection. Fine tuning every string of a piano or harp was a PITA because of the drift. In those early days, I just tuned one note, A = 440 Hz, and then relied on mathematics, listening for the sharpness and flatness of the natural harmonics.

Then solid-state devices came on the market, whose accuracy was, in some cases, woeful. Some used multivibrators whose components aged in unpredictable ways and some divided down from a higher xtal frequency, like electronic watches.

Cheers, Brian, VK2GCE

Brian Clarke
BE, MBA, PhD, CPEng,?APEC Engineer, IntPE(Aus),?FIEAust
MD, Clarke & Associates P/L

----- Original Message -----

From:

[email protected]

To:

<[email protected]>

Cc:

Sent:

Mon, 28 Nov 2022 16:41:09 +0000

Subject:

Re: [Test Equipment Design & Construction] Two interesting projects

Does any of this musical discussion, interesting (to some) though it is, have anything to do with Test Equipment?design?

The SNR of the thread has drifted alarmingly.

Pete

G4GJL?