#383 

What purpose would a analog oscilloscope serve if it couldn't take measurements? That's why it has calibrated time base and voltage settings for the scale.

@@mikesradiorepair Actually, early oscilloscopes didn't all have calibrated time base and voltage settings. The ability to "see" a waveform was big advantage of the scope. In fact, for the purpose shown here, he is not using the calibrated scales. Many years ago a friend gave me an ancient Heathkit scope which did not have a calibrated display.

These all Teks are such high quality equipment. They seem to last forever, and the pleasure of using their buttons seems unparalleled. They still sell for a good price. The only problem is the room they take.

No, but shortly after. Purchased in the late 80s I think.

Great scope! I hope you can fix it. The 485 has a very sharp trace on its CRT.

@@w2aew Even wilder, my 485 has a P11 phosphor CRT. It's the only scope in my collection with a P11 phosphor.

Sorry, not familiar with the book or the design of the direct conversion circuits in this book.

I have a playlist for oscilloscope basics, many of which feature the 465 B

Seemed like a fun use for a broken probe.

Well, I wasn't planning to do a part 2 (so no mention of it in the first video), so I just called it a follow up.

@@w2aewI see, thanks

I do have a few videos on measuring FM modulation index: Bessel Null method: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-8IBOYoIV5m8.htmlsi=b3609rda__8E5QUr Spectrum Analyzer method: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Nw3_w1HrlEs.htmlsi=oB8UkNpGjTKMgazs Unfortunately, there isn't a really good/accurate way to do this in the time domain with a scope because the change in frequency (deviation) is typically much, much smaller than the carrier frequency, so the difference is hard to measure. One more complicated option would be to down-convert to a lower frequency so that the deviation is a much larger fraction of the carrier (the principle behind the pulse counting FM detector: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-jQlN2fc7LJc.htmlsi=-LIZgbyeifYtIBv9).

@@w2aew Thank you very much! Will look into it.

The 100% scale is used mainly for 10-90% rise and fall time measurements. The 100% scale is shy of the graticule's full scale to account for overshoot/undershoot on the edges.