I’m considering getting an oscilloscope for general electronics stuff (mainly eurorack DIY stuff and some fiddling with microcontrollers), and figured since I do a bit of video synth DIY (just Cadets and Castles so far), I might want to be sure to spec my scope for video work too. From what I can tell, the upper bandwidth limit for composite video seems to be ~6.75MHz (or is it ~13.5MHz?) so would I just need a scope with that kind of bandwidth? Or do I need X times that bandwidth limit? Clearly I don’t know too much scopes, so feel free to school me!
I’d really love cheap recommendations, since I don’t want to drop a ton of money. But I’ll also welcome pricier recommendations to consider as more of a future goal.
Oh, and I should note, I already have a DSO138. I haven’t tried hooking it up to a video signal yet, but from the specs (and how generally not great it is), I doubt there’s much point in even trying.
[quote=“joem, post:1, topic:812, full:false”]
I don’t know too much scopes[/quote], either, so would also be interested in the answer, just thought it might be an idea to expand this to add:
and would look cool when a camera is pointed at it
I think that might be a different topic, maybe? A lot of old analog scopes can probably look cool on camera, but might not be cut out for video signal analysis. And video rate signals probably aren’t too exciting on camera, either, so if that’s your interest, you likely don’t need quite the same specs in a scope.
I personally use a Leader LBO 51MA X-Y Display Module for Vector Rescanning. I recommend a display module if you plan on using it for this. Try and find one that has the three X, Y, and Z BNC inputs located on the back. But, I think you can achieve similar results with just the X and Y inputs. You would also need three 3.5mm to BNC cables, so you can connect you LZX modular system up to the display.
do you want one for video rate electronics diy, or one for scan processing? if for video rate, i think a modern digital scope like a rigol would be good, you can capture lines to analyze, etc. they’re affordable (~$300) for a 4 channel, and the rigols can be ‘hacked’ to unlock more features.
@pbalj Yeah, I’m looking for one for video rate electronics diy. I’ve definitely been eying the Rigols and others like those, but I was kind of hoping there’d be something even more affordable than that.
Maybe some older (analog?) scopes that could be found cheaper than the Rigols second hand, that would still work ok for video rate electronics diy? Or are modern scopes the best to get the bandwidth needed at an affordable price?
I think I’m using a 25mhz analog scope. It works alright. It’s hard to view the high end of video signals with it but I do fine. I think most analog scopes will be alright above 20mhz. 50 or above is probably most ideal. Could probably be had for very cheap compared to a rigol. Rigol is in my list though, I need to replace my bulky scope on my bench
I have a Tektronix 465B and a Rigol DS1102E. Quite good scopes can be had on eBay nowadays (shipping costs and packaging are always a bit of an issue…)
@pbalj the Rigol is QUITE convenient and has a host of easy to use features…
hello
i ve checked the Rigol ds 1000z serie manual, and can’t find an xyz mode. there s an xy mode but no brightness modulation from a third channel(z mode). Strange no ?
im not aware of any modern digital scopes that use a z (brightness) input. could be wrong.
this thread is more discussing good tools for measurement of video signals, in the creation of electronics, as opposed to artistic purposes, which in our world z is usually used for.
The Tektronix 465B is one of the nicest (IMHO) portable analog scopes Tek ever made. Honestly, sometimes I prefer the 465B over my 5000 series MSO because it doesn’t take 5 minutes to boot and go through self-calibration.
Rigols are a solid choice and the price point is right on. On some models like the DS1104, you have the option of a built-in function generator (out to 25 MHz) which can be VERY useful for video/eurorack/general synth development.
Its an amazing scope for DIY and analyze (freq meter, voltage refs, etc) and has very good bandwidth … but the screen is not that good for capturing and processing stuff (it does have xyz).
Absolute noob question…how do you get the signal into the oscilloscope? Do you need to build a probe? It’s convenient that the mordax has 1/8 jacks… How do you eurorack > rigol?
You can get an oscilloscope probe and a bare minijack plug (like for making your own cables), and just clip the scope probe to the tip (signal) and sleeve (ground) lugs. This is probably the best option for signal integrity since scope probes are designed to not interfere with the signal. For a quick check on something I’ve also used a 1/8" to RCA adapter cable and a RCA to BNC adapter (basically all scope input connectors are BNC) but this will distort the waveform due to cable capacitance and stuff.
