I build the ATtiny85 version today, and also tested the rise times. I got very optimistic rise times in the order of 600..800 pSec.
I used an Tektronix Type 284 pulser with a very short cable. This has a spec of 70 pSec rise time @200 mV.
Time base was set to the initial 1 nSec, and 250 MHz BW.
It made me suspicious since this rise time is not really possible with this scope. I did a further check with an 200MHz signal gen. It turns out that the actual timebase setting was 2nSec despite the fact that the setting was indicating 1nSec. All time measurements on screen are based on the 1nSec/div.
I made a new version of the ATtiny85 hack and set it to 2 nSec. This all was tested with the latest firmware 00.01.00.00.03 on a DS2072.
I now have a more realistic rise time of 1.4nSec. (0.33/1.4 = 235MHz)
So it seems that the DS2000 series can handle max 2 nSec.
A big
thank you to Studio25 for his nice work.
Update : Done some more testing by changing the BW settings from 0x04 to 0x05; the result is that the scope shows no BW any longer in the menu, but stays at the 250MHz setting.
Attached are the 1nSec screen shots of a 200 MHz signal. There is a difference in single or dual mode. Single mode seems to be OK.
For the moment I'll keep it 2nSec. Still not bad for a 70MHz model
Perhaps RIGOL can fix this bug for us
- Orange