1. I am confused between two scopes series of Keysight 3000 and the 4000 series except for the bigger size screen what is the difference?
I'm a little late to the party, but the 3000T and 4000 X-Series are very similar with a few notable exceptions. Also, the 4000 X-Series generally runs ~15% more $.
The 3000T X-Series perks:
- Display a math channel & FFT at the same time
- optional 8 digit counter + totalizer (vs. 5-digit counter)
- 1.6 ppm timebase accuracy (vs. 10)
The 4000 X-Series
- Bigger screen
- optional dual channel WaveGen, larger output voltage
- 4 Match channels (vs. 2)
- 10 MHz reference in/out
- LAN/VGA standard (vs. optional)
- Can use 4 active probes without extra power supply (vs. 2)
- 3 USB host ports (vs. 2)
- 700 MHz probes included (vs. 500 MHz)
If you ever need 4 active probes at once (like for SMPS testing), the 4000 X-Series is a way better option.
Keep in mind that if you buy the Keysight 500 MHz scope the upgrade to 1 GHz is a replacement of the mainboard - there is no software/firmware upgrade.
It is a new board to go from 500 MHz to 1 GHz. But, buying the 500 MHz scope then upgrading to 1 GHz will cost you the same $ as just buying the 1 GHz from the beginning. So, the only cost is in lost lab time.
EDIT: I took a quick look in the more recent Programmer Manuals. For at least the X4000 and X3000T, the manual lists the reference waveform as a possible input for MATH functions. So, presumably this issue has been addressed but I'd still want to see it in action.
Confirmed