My 1960s oscilloscope is finally getting a bit old & troublesome.
It's an S.E Labs SM111 which I have had since 1988, when I bought it from a test equipment dealer in Reading UK for £250. it's a fairly standard 18MHz dual trace, which I use for general purpose use for analogue & fairly slow digital/embedded micro projects.
It has another advantage of providing heat for my shed when I use it!
I want to replace it with something newer, but am not sure if I should go for a used Cathode Ray Oscilloscope (CRO) from a respected manufacturer such as Tektronix/Philips, or should i look at a newer type LCD model by one of the imported Hantek/Tekway/Rigol makes.
I have about £200 to spend. My requirements are dual channels as a minimum, although I can buy models with upto 4 channels. I think I should be aiming at about 100MHz bandwidth since I will be using it on PICS/Arduinos to about 20MHz.
On one hand I'm tempted towards a traditional type CRO, but cannot ignore the modern LCD ones.
But I have never heard of some of these manufacturers, so am worried about the risks of buying such. Therein lies my quandary!
It would appear that the modern LCDs specification would give much more capability; such as Spectrum/FFT Analysis, Logic Analysis etc. I've also seen some claims that extra bandwidth may be 'unlocked' by updating firmware, but this is not really a factor that would influence me greatly.
Any advice or suggestions would be greatly appreciated, as I can find discussion from both points of view.
I can't provide you links to you tube from work, but I suggest you check out Dave Jones at EEVBlog there. He has reviews of various inexpensive LCD scopes and older CRO scopes.
Whatever go for a storage 'scope, an analog 'scope won't be able to show high-speed
one-off events. Having distinct colours for each trace is also surprisingly nice to have,
although the on-screen data is a more obviously useful advantage.
Like Mark says, the digital storage is really nice. The only reason I'd even consider an analog 'scope is because of cost. (I don't have a 'scope at home and an analog 'scope is better than nothing!)
Most digital 'scopes also have a way to capture the image, which sure beats a Polaroid 'scope camera if you need to send/share a waveform!
There are digital 'scopes with cathode ray tube displays. They are more bulky than LCD and they are always monochrome. And, you have to adjust the focus and occasionally make some other "analog adjustments" to the display. (The least-expensive LCD 'scopes are also monochrome.) I can't think of any downside to LCD, except you might find a CRT 'scope at a lower cost . (We call it a cathode ray tube in the U.S.)
At work we have 2 & 4 channel color LCD 'scopes (Tektronix). It is nice to have different color traces for each channel, but most of the time I'm only using one channel anyway. Depending on the cost, I could live without that.
Data lines, address lines, and audio signals are non-repetitive and you already know what a mess they look like on an analog 'scope. On a digital 'scope you can "capture" the waveform, it looks a lot cleaner and often you get a better picture of what's going-on.
Or if you have a short-duration infrequent pulse, you get a dim-flickering image on an analog 'scope, whereas with digital you get a nice image.
Low frequency stuff also tends to flicker with an analog 'scope, or at very low sweep-rates you have to watch the dot trace-across the screen.
I think that because of my limited budget I will be going to get either of the following:-
Hantek DSO5072P 70MHz 2CH Digital Oscilloscope 1GSa/s DSO, or
Hantek DSO5102P 100MHz 2CH Digital Oscilloscope 1GSa/s.
These seem like good oscilloscopes compared to what I currently have!
It's just a question of choosing 70MHz or 100 MHz bandwidth. I have heard that these machines are identical, & that the 100MHz or even 200MHz can be unlocked by updating firmware using the USB port. But 70MHz is probably enough for me.
