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Analog vs digital X-Y mode
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joeqsmith:
I had someone ask me about the X-Y mode on one of my old scopes.  I was not sure what they were asking so I ran is various settings. One comment I had was about the sparse amount of data.  I suspect they were thinking audio and I was looking at much higher frequencies.   

Is the goal here just use use a scope for art?   I watched some of these fancy YT videos like the one linked above.   I then tried using Labview to put together a simple program to use the sound card but it was far too slow.   I ripped some of the audio tracks from YT and then tried it with some of the dedicated PC sound card scopes.  Looks like they may do a decent job.   YT compresses the audio so the graphics don't look very impressive but the dedicated programs far exceed what I could do with Labview.   I tried playing these files into one of my scopes and could post a clip but it's not very impressive with the YT compression.   At best you would have some idea on the update rate of my old scopes. 

As mentioned, I think if the goal is to benchmark the visual effects, a standard audio clip may be a good place to start.       

The letter 'D'
JohnnyMalaria:

--- Quote from: joeqsmith on May 24, 2018, 04:34:30 am ---Is the goal here just use use a scope for art?   I watched some of these fancy YT videos like the one linked above.
--- End quote ---

Sometimes science is art :)

I created the clips with preset waveforms from my function generator (such as chirp, FM modulation etc). The signals were demodulated about a fixed frequency to generate a quadrature pair which are the XY signals (like a lock-in amplifier).

My real-world application is demodulation of a modulated photodetector signal from nanoparticles moving in a liquid. The phase information in the signal relates to the position of the particles. If the particles are just moving randomly, the XY trace will show a random walk. If there is linear motion such as due to movement in an electric field, the phase will change linearly and the XY trace will rotate. Observing this directly and live on a CRT scope in XY mode is tremendously valuable. It tells me if there are issues with sample or hardware and I can "see" when the particles are moving due to the electric field (which is the primary purpose of the experiment). Without this, I'd be working "blind". It is analogous to the use of vectorscopes for video. For my particular application, the frequencies are in the audio band.
joeqsmith:

--- Quote from: bd139 on May 22, 2018, 11:10:37 am ---Someone should try this on an HP 546xx. They have a superior X-Y mode. Not bad for 1994...

https://youtu.be/D2uEvRPd4w8

--- End quote ---

Hunting around this site, I found were this same post was made in 2012 or so.  Someone had the raw file but the links were dead.  Doing a quick Google search, the are still available if we wanted to use this as some sort of benchmark.    Just search for oscillofun.flac. 


--- Quote from: JohnnyMalaria on May 24, 2018, 12:57:45 pm ---
--- Quote from: joeqsmith on May 24, 2018, 04:34:30 am ---Is the goal here just use use a scope for art?   I watched some of these fancy YT videos like the one linked above.
--- End quote ---

Sometimes science is art :)

I created the clips with preset waveforms from my function generator (such as chirp, FM modulation etc). The signals were demodulated about a fixed frequency to generate a quadrature pair which are the XY signals (like a lock-in amplifier).

My real-world application is demodulation of a modulated photodetector signal from nanoparticles moving in a liquid. The phase information in the signal relates to the position of the particles. If the particles are just moving randomly, the XY trace will show a random walk. If there is linear motion such as due to movement in an electric field, the phase will change linearly and the XY trace will rotate. Observing this directly and live on a CRT scope in XY mode is tremendously valuable. It tells me if there are issues with sample or hardware and I can "see" when the particles are moving due to the electric field (which is the primary purpose of the experiment). Without this, I'd be working "blind". It is analogous to the use of vectorscopes for video. For my particular application, the frequencies are in the audio band.

--- End quote ---

If you wanted to detail a setup, we could use this as a test case as well.   Or if you wanted to model it in software and create a raw WAV file, that may make things even easier and possible allow more people to run it for you.   
joeqsmith:
Link to the oldest thread I could find showing oscillofun.

https://www.eevblog.com/forum/suggestions/audio-signals-quality-in-x-y-mode-what-is-important-what-is-not/msg164751/#msg164751
james_s:
I use the XY mode on my 465B scope while working on vector arcade game boards, it's a lot more convenient than trying to rig up a fullsized vector monitor which are rare and valuable in addition to being bulky, fragile and requiring some odd voltages.
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