Waveform Monitors and Vectorscopes
Posted 14 August 2006 - 09:24 AM
Posted 14 August 2006 - 11:24 AM
I've known how to use both for years, first having learned to use standard oscilloscopes by the time I was 18 or so - but when I googled to find a book it turns out that the pickings are pretty slim. I did find the old Tab Books "How to use vectorscopes, oscilloscopes & sweep-signal generators" on Amazon. It's by Stan Prentiss, he was a pretty good writer of beginner texts.
I'm curious as to where you guys have familiarized yourselves and become acquainted with waveform monitors and vectorscopes.
You might consider buying a cheap oscilloscope off eBay and use it as a trainer. A standard oscilloscope is basically the same equipment as a waveform monitor but without the presets a waveform monitor has that make it easy to use. You want an analog, not digital or LCD, scope. Look for one designed for TV servicing like the BK Precision 1400 series. $50 or so plus shipping should be enough for a working, older analog scope.
It's a bit hard to explain but modern digital and LCD scopes are very unsuited for measuring signals with a wide range of frequencies like video where the scope has to handle 59.94Hz vertical sync while simultaneously displaying video as high as 4.2MHz for NTSC and much higher for HD. There are digitals and LCD scopes that will do that but you won't find one for under $1K used. For instance, I've got a Fluke 99B Scopemeter LCD scope I bought for electronic servicing that is absolutely worthless for looking at video.
Once you've got your cheap eBay scope and the Tab book then start using it to look at all sorts of video, off cameras, DVD's, VCR's, the AV outputs on TV's, etc. By practicing with a regular scope, you'll be able to learn to use a regular waveform monitor quickly. A true waveform monitor has some extra functions but they make sense if you know what a video signal consists of.
I've seen the old Tektronix 520 NTSC vectorscopes go for as little as $50 on eBay, the shipping for one is going to be at least $25. I would buy one that is represented as working, you don't want to get involved with a sick one. I got lucky and bought one for $35 last year that I use in my shop that looks and works like new.
PM me if you see a scope or vectorscope on eBay you'd like my opinion of. Like everything on eBay you're somewhat at the mercy of the seller's ethics. I've bought and sold a lot of test equipment on eBay and can get a pretty good sense of just how good a piece of equipment is from the description, photos, and who the seller is.
Posted 19 August 2006 - 01:58 AM
I'm curious as to where you guys have familiarized yourselves and become acquainted with waveform monitors and vectorscopes. Obviously on-set would be one place but I only ask because I never had the opportunity to get my hands on one in school and I still don't see many classes out there offering training on them or integrating them into the curriculum (yet). Thanks, as always, for the input.
Take a look at http://www.pixelmong...m/art_hist.html
For an alternative way to measure video levels. Very simple!
Posted 19 August 2006 - 11:08 AM