#804 

I wondered about the "fix up" for the Rigol, never go around to doing my DS4024, will give it a try some day, I guess it's out of warranty by now. Never really wanted to mess around fearing I would brick the thing. The other week I was comparing two Rubidium oscillators that at 100Mhz (after a 10 clock multiplier) thinking, be cool if I could get the Rigol to display at 500Mhz I would add another 5x multiplier to the testing. I should look to for the fixing data. Thanks for the video, possibly will bump into each other at excess or Anchor some day.

You have to consider that you use square signal at imput. To preserve squere signal integrity, you need bandwidth at least 5 * first harmonic @ 100MHZ its 500 MHZ of bandwidth... This is my rule of thumb.

Hi! Nice video. Could you please generate a RU-vid video on how you "Hacked" your Rigol SA1074Z Scope. I tried to follow your suggested "Instructable" link, but a number of procedures were not clear to me. For example, where did the Telnet part fit into the scope set up? A lot of us would most probably like your special interpretation as to how to Hack your scope! Thanks.

What happens when all 4 channels are in use at the same time? I think the same hardware is used for 50Mhz - 200Mhz versions but the badged 200 is a two channel only; the 1202z unit.

Thanks for showing the achilles heel of these modern DSO scopes. I have a Siglent 1104X-E, an old Tektronix 784A, and an older yet Tektronix 2230 (analog). I do a lot of high power audio amplifier work, so I do not really approach the limits of any of these oscilloscopes, but, I still prefer my Tek 2230 analog scope for some reason. I can't place my finger on any one thing, but perhaps it is because I was schooled with analog and it is just what I like to use. This happens to be a topic where there are many differing views, from many different perspectives, BTW! Regardless, thanks for the insightful video. Fred

With 1 GSa/s capability, I thought the aliasing wouldn't occur until about 500 MHz. I have an old Tek TDS784A scope that also has 1 GSa/s. I'll have to try the same thing. I think I'll use a sine function instead of the square wave though.

Is the output of that signal generator leveled ? If it isn't then it's a case of Heisenberg's uncertainty principle. note. I'm sure it's not leveled in any way but that's just feeling not actually looking at the boards specs :-)

Does the "breaking" have anything to do with the screens refresh rate?

just tested my DS1102ze not hacked -. rated at 100mhz I was able to get clean sine with internal hardware counter up to 215mhz

Hi, thanks. Is there a way of testing and verifying the bandwidth up to 500 MHz without fancy expensive equipment? I don't have a function generator that goes that hi.

Maybe you can turn off the interpolation explicitly on the rigol also and benefit from the vector-mode if there are only a few points. This should make more visible whats going on by conntecting the dots with straight lines instead of showing what looks nices (Everyone likes sinusoidials :-))

What signal generator are you using ?

Do you have a good used Tektronix with 500mhtz or better? Can't believe you don't, being a lab guy. Thanks for the look.

Bandwidth is measured -3dB (voltage) of a sine wave. The input in the test is probably from an function generator which can't provide the clean sine wave.

I think you would get better results if you use the TinySA as a generator since it produces sine waves. I have used it to measure the bandwidth of my Tektronix 465B which is rated at 100 MHz. With the TinySA, it came out as 130 MHz which is reasonable since Tektronix was conservative with their specs. Also , note that dB is dB. What that means is that 3 dB is 3dB whether referred to voltage or power. Thus 3 dB down in power is 1/2. 3 dB down in voltage is .707 which, since it is voltage, is also 1/2 power. Bandwidth is usually defined as 1/2 power which is why you use 0.707 as the factor when applying voltage to measure the bandwidth of an oscilloscope.

Most all digital oscilloscopes do a sinx(x) - Interpolation on the trace. This may help to get a more realistic trace, if you have enough sample-points. If there are only a few sample-points availabe, they fool you because they show sinusoidial traces instead of the real sample values. On my Siglent, this feature can be turned off explicitly. I set the default to disabled. It looks like your Rigol turns this "feature" off when you switch to point-display.

huh 70% it is -3.09db or -6.18db for a power.

Activate the frequency counter ;-)

I just copied from tek website, better then me trying to explain(www.tek.com/support/faqs/how-bandwidth-related-rise-time-oscilloscopes) Historically, oscilloscope frequency response tended to approximately follow the rule: Bandwidth x risetime = 0.35. This corresponds to a 1- or 2-pole filter roll-off in the frequency domain. Today, at the high end, most real-time digital oscilloscopes more closely follow this rule: Bandwidth x rise time = 0.45. This corresponds to a much steeper frequency roll-off above the specified bandwidth. The steeper roll-off is more desirable in digital oscilloscopes that oversample by 4x, 3x, or even less because it prevents aliasing by eliminating any signal above the Nyquist frequency (1/2 the sample rate - the minimum sample rate required for accurate signal representation). So if you have a fast pulse gen like leo bodnars 40 pS gen you can calculate bandwidth from risetime, a standard risetime measurement is in every scope nowadays.