Fun with digital scope

[bob91343]

I am using a simple audio oscillator.  I do have some old function generators so maybe I'll break one out and see about offset.

[bob91343]

That seemed to work.  I now can see the classic amplitude modulated wave.

However, I am unsure of just what I am doing.  As I vary the dc offset I see the wave move up and down until clipping.  If I vary the ac component the wave reaches 100% modulation and continues beyond to something I can't really understand.  It folds over and rather than flatten at the axis, it goes beneath and remains sinusoidal.

[David Hess]

More amusing is that some of these old DSOs, like the mentioned 2221, can synchronously demodulate AM directly from RF to recover the original audio by using their external sample-clock input.

[bob91343]

I still feel that the analog scope's days are not yet over.  Much simpler to use for troubleshooting and casual measurements.  For demanding applications, the digital is probably superior.

[Fungus]

I still feel that the analog scope's days are not yet over.  Much simpler to use for troubleshooting and casual measurements.  For demanding applications, the digital is probably superior.

I don't think anybody denies they're beautiful and awesome, but... very limited in what they can do.

And they take up a lot of space.

[bob91343]

My digital and analog scopes are about the same size.

[tautech]

My digital and analog scopes are about the same size.

I was trying to learn to use my Tektronix 2440 digital scope.

I hate to inform you a 2240 would be considered as a dinosaur today.
A modern and compact DSO has far more functionality.

[David Hess]

I hate to inform you a 2240 would be considered as a dinosaur today.
A modern and compact DSO has far more functionality.

But not delayed sweep, so most modern DSOs cannot for instance measure the timing difference between adjacent pulse per second pulses at their best resolution.  Doing so would require upwards of a 1 Gigasample record length.  An old DSO only requires a 32 bit counter.  Modern high end DSOs get around this limitation with segmented memory.

I would agree that analog and older digital storage oscilloscopes are long obsolete, but that does not make every "modern" DSO better for every application.  Some modern instruments are pretty horrid.

My digital and analog scopes are about the same size.

Since my most used DSO is a Tektronix 2232, my most used digital and analog oscilloscopes are exactly the same size.

[bob91343]

My old HP 54542A has a larger front panel but it's not too deep.  That is a very old digital scope that I like a lot.