FYI - my very first scope - in my school "electronics lab" - I didn't want to make the planned "digital clock kit " (I had already made one - and not from a kit) - the instructor asked what I'd like to create, and I said "I'd really like to have an oscilloscope".

Next week - everyone else had a "clock kit" on their desk - I had a 3KP1 video tube with a photocopy of an EICO scope schematic wrapped around it!

https://dunfield.themindfactory.com/Drop/oscope.jpg

It worked surprisingly well - I never really tried to go "high speed" (I was hand wiring scavenged tubes and transistors in most of my "projects" - nothing fast at all), but we tested it up to 25mhz and everything looked right!

DaveDDS wrote on Yesterday, 05:20:

lti wrote on 2025-12-07, 21:01:

... I see a Rigol pop up a lot ..., but I'd rather have an internal power supply that doesn't need an external ground lead.

Most of my bench scopes have been grounded (and I've had a LOT over the years - incl. a number of Teks)
In most cases, you are referencing to ground on the system under test, and I don't like attaching a large floating (non grounded) bit of test equipment to a test systen "ground" on my bench.

The new low-end Rigols (DHO800, DHO900, and MSO900) are the first scopes I ever saw that weren't grounded through the power cord. They use an external USB C power supply instead, and since USB C power supplies have floating outputs, they need a separate ground wire.

The DHO800 is a popular model today because of the USB C power and because it's one of the cheapest scopes on the market with 12-bit ADCs. I don't think 12-bit resolution is absolutely required today, but if you're buying something new and have the budget for it, it's nice to have (and if you have a corporate budget and are already looking at high bandwidth and high sample rate, 8-bit looks antiquated). I have seen some cases where it makes a difference, but you can get pretty far with a Tektronix TDS210.

DaveDDS wrote on 2025-12-07, 22:30:

lti wrote on 2025-12-07, 21:01:

... It kind of annoys me that some large high-end scopes don't have separate controls for each channel ...

Yes, can be very annoying (completely understandable in a scopemeter as you don't typically see knobs all over a handheld)

And as scopes get packed with more and more features and settings, I guess makers have to find some way to keep from returning to the massive devices needing special "scope carts" we used to use and channel controls are typically the same for each channel - makes it easy to implement only one switchable set.

The trend of larger screens also reduces space for controls, even if you don't count that LeCroy with a 15.6" 1080p screen.

lti wrote on Today, 02:53:

The new low-end Rigols (DHO800, DHO900, and MSO900) are the first scopes I ever saw that weren't grounded through the power cord. They use an external USB C power supply instead, and since USB C power supplies have floating outputs, they need a separate ground wire.

.. Interesting .. is USB-C by nature floating ground? I always assumed it was like any other USB and ground in common with the host PC.

The OWON VDS-1022 I have is actually a "1022I" which means "isolated" (from ground). But that is separate (and slightly more expensive) from the VDS-1022(no I) which is not isolated. I don't have it in front of me, but IIRC it has a 2->1 USB cable for interface/power and it's an expanded micro-USB (wth the extra bit to one side)

I don't personally need a 12-bit DAC (4096 levels) - always nice, but 8-bit (256 levels) is almost always more than enough resolution for me.
- If I'm looking at a 3v signal, do I really need to know within 0.000732v instead of 0.017188v - there are cases where this matters, but I almost never need it.

The trend of larger screens also reduces space for controls...

Good point - but there are quite a few with "normal" screen sizes with collected into-1 channel controls - My Rigol DS1054Z (4-chan - 1 control group) is not apparently bigger (I've not measured) screen size then my TDS210 (2-chan - 2 control groups).

DaveDDS wrote on Today, 03:41:

.. Interesting .. is USB-C by nature floating ground? I always assumed it was like any other USB and ground in common with the host PC.

The Rigol models I listed are full bench scopes that are powered by a USB C charger. Those little power bricks tend to be floating (regardless of output connector), but I don't think there's any requirement for it in the USB-C PD spec.
https://www.rigolna.com/products/digital-osci … oscopes/dho800/

lti wrote on Today, 04:05:

The Rigol models I listed are full bench scopes that are powered by a USB C charger. ...

Ahh... Ok, I understand - a brick makes sense (and would indeed be isolated) - I was assuming the USB was also for a (hopefully optional) PC interface.