EEVblog Electronics Community Forum

Products => Test Equipment => Topic started by: MikeK on February 11, 2021, 03:53:33 am

Title: Rigol DS1052E 100MHz mod worth it?
Post by: MikeK on February 11, 2021, 03:53:33 am
I've had my scope for years and finally did the 100MHz mod.  Okay, sure, I can now zoom in to 2ns, but I never needed that depth.  I was able to accurately probe a 110MHz signal before the mod...The scope was accurately calculating the frequency.  And that was about the limit; any higher and it couldn't handle it.  And now that the mod is done, it's the same.  Still nothing better than 110MHz.  So what did I gain from the mod, besides the 2ns depth?  Shouldn't 100MHz be the 3dB point?  Shouldn't I be able to at least get some higher frequency, albeit with some attenuation?

-Mike
Title: Re: Rigol DS1052E 100MHz mod worth it?
Post by: Fungus on February 11, 2021, 10:03:54 am
The 100MHz mod only changes the -3dB point. You'd see a 110MHz before but it would have been more attenuated.

If you only look at pure sine waves then you won't see a huge difference but a high frequency square wave should now look more square than it did before.

Was it worth doing? That depends on what you look at with your 'scope. Changing the ratio of sample rate to -3dB point also has consequences (although 1Gs/s is still plenty for a 2-channel 100MHz 'scope).
Title: Re: Rigol DS1052E 100MHz mod worth it?
Post by: MikeK on February 11, 2021, 02:21:16 pm
Okay, so if I could see a 100MHz signal on my *then* 50MHz scope...Shouldn't I be able to see a 150MHz or 200MHz on my *now* 100MHz scope (just with attenuation)?  Because it still craps out at about 110MHz.
Title: Re: Rigol DS1052E 100MHz mod worth it?
Post by: Fungus on February 11, 2021, 02:33:45 pm
Quote from: MikeK on February 11, 2021, 02:21:16 pm
Okay, so if I could see a 100MHz signal on my *then* 50MHz scope...Shouldn't I be able to see a 150MHz or 200MHz on my *now* 100MHz scope (just with attenuation)?  Because it still craps out at about 110MHz.

Theory says: If you feed it a pure sine wave via 50-Ohm terminated BNC cable it should gradually attenuate as the frequency rises, reach -3dB at 100MHz, and start "crapping out" at about 400MHz (ie. 1GHz / 2.5).

If it "craps out" before 400Mhz then it's due to your probes or something else.  :-//

nb. Most 'scopes have a bit of extra headroom so -3dB is likely to be at 120Mhz or around there.
Title: Re: Rigol DS1052E 100MHz mod worth it?
Post by: MikeK on February 11, 2021, 02:54:34 pm
It could be my DDS signal generator.  When I got to 150MHz, the 'scope showed a good signal again.  I'll have to dig deeper.

Thank you.

-Mike