Oscilloscope

Anything to do with the things that make the music we listen to.
Michael L
Old Hand
Posts: 478
Joined: Tue Feb 19, 2013 5:10 pm
Location: Shrewsbury

Post by Michael L » Sun Jan 04, 2015 7:12 pm

After further scouring t'internet I don't know whether to get a digital scope with 3 years warranty or a used analogue scope that may keel over
and need parts that are no longer available.
Digital scopes are apparently less tolerant of over voltage slip ups though
so it would be relatively easy to kill the scope when working on valve circuits if the probe was set incorrectly.

Can anyone advise?

User avatar
jack
Shed dweller
Posts: 2893
Joined: Wed Dec 29, 2010 8:58 pm
Location: Somewhere getting cooler with a faint possibility of rain.
Contact:

Post by jack » Fri Feb 06, 2015 10:28 am

I use both - An analogue Tek 2465B and a Tek digital jobbie.

By preference, I always use the analogue scope - it misses absolutely nothing and has such a HUGE genuine bandwidth (400MHz) that no artifact, however small, will get missed.

Only certain Tek 2465s had problems, and spares are readily available. Touch wood, I've been using mine for 15 years and barring replacing one input attenuator (I blew it up) which cost me about 50 quid and about 2 hours to re-do the calibration, its not missed a beat.

The digital scope is great for certain things - it has inbuilt FFT and you can print from it, i.e. its really useful for documenting stuff. Functionally, its not a lot different from the analogue scope, i.e. cursors, measurements etc. but I also don't like the granular nature of the 8-bit displays that almost all of them have, and that they can miss spikes and use over-sampling to get stated bandwidths - If you are looking for subtle artefacts in an analogue waveform, e.g. at crossover on a sine wave, a digital scope can be a bit of a pain due to its display's quantisation distortion.

In summary, each has its strengths, but for analogue work, I definitely prefer an analogue scope...

...but I'm glad that I have the digital one too for other stuff :)

Actually, I'm looking very hard at some of the desperately cool digital and mixed-mode USB scopes that are around, including places like KickStarter, e.g. https://www.kickstarter.com/projects/75 ... cilloscope & https://www.lab-nation.com/ - These USB jobbies often are mixed mode, i.e. can be used as logic analysers with protocol decoders etc., and often contain things like AWGs - kinda cool...

Post Reply