Stoopid Rigol Question - Page 1
Forum section: electronics / testgear

author: Mr. Coffee
author_rank: Regular Contributor
timestamp: April 08, 2014, 11:03:44 pm
content: Hi, fellas,I just got a Rigol DS1052E 50MHz scope for general (mostly AM medium wave radio resto work...and maybe a little 11 meter AM CB) and saw today that they make a 100MHz version with the same model for little more money. Strange the model number is the same...but did I underbuy? I don't think I'll need more than 50 MHz, but I know the closer you get to the -3dB poiunt, the less absolute accuracy you get. Am I good for casual 26MHz-27MHz hobby work?

author: pickle9000
author_rank: Super Contributor
timestamp: April 08, 2014, 11:18:15 pm
content: Have funhttps://www.eevblog.com/forum/blog/changing-the-rigol-ds1052e-to-ds1102e-using-usb-the-dummy-guide/

author: theatrus
author_rank: Frequent Contributor
timestamp: April 08, 2014, 11:57:52 pm
content: The 100MHz is the 1102, but as posted there are ways around this :-)

author: miguelvp
author_rank: Super Contributor
timestamp: April 09, 2014, 12:56:00 am
content: Just be aware that things can go wrong, so be very careful!https://www.eevblog.com/forum/blog/the-dark-side-of-the-rigol-hack-bricked-scope-how-to-fix-it/

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: April 09, 2014, 01:18:22 am
content: I see no one's answered your question but someone will eventually. If you can return your scope you may find that you can buy the 100MHz model for less. At least when I looked into these models coupla months ago the 100 was less than the 50. I thought the 100 had a larger screen too.

author: Mr. Coffee
author_rank: Regular Contributor
timestamp: April 09, 2014, 02:59:42 am
content: Thanks for the input you all, but I won't be getting inside of it anytime soon. I just wondered if I was losing a really significant amount of accuracy taking the 50MHz scope to slightly more than half its bandwidth.

author: Mr. Coffee
author_rank: Regular Contributor
timestamp: April 09, 2014, 03:13:57 am
content: I found this:http://www.google.com/url?sa=t&rct=j&q=&esrc=s&frm=1&source=web&cd=5&ved=0CEAQFjAE&url=http%3A%2F%2Fwww.electron.frba.utn.edu.ar%2F~jcecconi%2FBibliografia%2F06%2520-%2520Osciloscopios%2520de%2520Almacenamiento%2520Digital%2FUnderstanding_Oscilloscope_BW_RiseT_And_Signal_Fidelity.pdf&ei=H7hEU-KPIeL4yQGV2oHoDA&usg=AFQjCNFnp-nNucaqGAOzU3VEl35SpOgNygIt is what I was looking for. I will keep this scope. It looks like I should get a usable figure for the occasional higher frequency work I do.

author: Mark_O
author_rank: Frequent Contributor
timestamp: April 09, 2014, 04:03:10 am
content: Quote from: Mr. Coffee on April 08, 2014, 11:03:44 pmNo, it's not.QuoteYes.

author: hamster_nz
author_rank: Super Contributor
timestamp: April 09, 2014, 04:13:27 am
content: On reading that document linked by Mr Coffee, I think that it is marching into audiophool-like psuedo-information.So many sweeping assumptions, and somewhat inaccurate statements...."Complex signals, according to mathematics theory, can contain many spectral (sine) components".... Great, and what about in the real world?"Spectral Analysis can tell us what these sine wave components are for a repeating signal...". So me hooking up a probe to a monostable 555 makes this whole section void?"Most people are interested in time measurements...". So now I'm an odd-ball if I want frequency measurement...."Niquest theory is violated and the signal is reconstructed in a false way...". What the heck?and so on....Now I fully understand what they talk about and can see what they are trying (very badly) to say, but I have to wonder if an engineer was actually involved in approving that document!

author: Mark_O
author_rank: Frequent Contributor
timestamp: April 09, 2014, 05:16:28 am
content: Quote from: hamster_nz on April 09, 2014, 04:13:27 amSadly, I don't have time to respond to this point by point, but I'll just get it on the record that I disagree with every point you tried to make.

author: edavid
author_rank: Super Contributor
timestamp: April 09, 2014, 05:28:58 am
content: Quote from: GiskardReventlov on April 09, 2014, 01:18:22 amThis is not right either - the Rigol low end lineup is:DS1052E 50MHz 5" $330, can be hacked to 100MHzDS1102E 100MHz 5" $400DS1074Z 70MHz 7" $585, can be hacked to 100MHz

author: hamster_nz
author_rank: Super Contributor
timestamp: April 09, 2014, 05:49:45 am
content: Quote from: Mark_O on April 09, 2014, 05:16:28 amWhy didn't they just say:"Complex signals contain many spectral (frequency) components""Spectral analysis allows us to find the sine wave components of a signal..."."If the requirements of the Nyquest limit is not met you will not adiquately capture the frequency components of the signal, so any reconstruction of the waveform is incorrect"Far clearer, far less wordy, and more accurate...

author: Mr. Coffee
author_rank: Regular Contributor
timestamp: April 09, 2014, 10:20:06 am
content: I misread the model number of the 100MHz model...oops. I don't know enough about that document I linked to, to know if it's BS or not.But as far as frequency response, finding some other info information online does seem to agree in general with the concept that if I am reading 27MHz on a 50MHz scope it will likely be sufficiently accurate for my purposes... ~ -8% to -10%.cheersRob