Seems that I'm gonna have my first oscilloscope.
I have taken into account the bunch of advice given for the selection.
And I come with 2 candidates, restricted for my budget U$300-U$400:
1) Digital Owon PDS5022 25MHz
http://www.owon.com.cn/eng/pds.asp
2) Analogue BKPrecision BK2120B 30MHz
http://www.bkprecision.com/products...al-trace-analog-oscilloscope-with-probes.html
I have general knowledge, with many gaps, about everything on electronics, but I wanna learn the inners of electronics, in order to design circuits.

Following the advice of Kuphaldt books and Horowitz Art of Electronics, among other sources, I want to hook my oscilloscope to any possible signal, from simple AC voltage dividers to DC microprocessor circuits, passing by transistors amplifiers, opamps, discrete digital, audio/video signals, troubleshooting tv/radio/cd, etc.

And I'm here with 2 doubts:
- How much important is the display intensity graduation difference on my 2 candidates, when viewing tv/video signals, CDROM signals, other complex signals?
- How much time an oscilloscope takes to be in need of a specialized calibration, and is the same on both models?

Thanks in advance.

 

For all around usage, an analog o'scope is preferable. DSO's are a bit trickier to set up, as an unoptimum sampling rate can lead to an aliased presentation (see link - http://shalin.wordpress.com/tag/nyquist-sampling/).

I can't quite get what your concern is about display intensity.

Unless you are planning on some really hairy measurements, o'scope calibration is probably not going to be a concern. You use a meter for accurate voltage measurement, and you can always get a frequency counter for that function.

 

About display intensity I mean the difference between the showed graphic of a complex signal (i.e. video composite) in an analog scope vs the digital one.
That is showed in http://www.radioradar.net/en/measurements_technics/oscilloscope_display.html

 

The truism is that no o'scope can do it all. I am probably biased towards analog instruments, as those were the first ones I used (and am still using). For low bandwidth, I would still say analog, despite my obvious bias. Above 250 MHz, digital is probably better.