RTB2004 from R&S signal vanishes at some frequencies - Page 1
Forum section: electronics / testgear

author: Netroman
author_rank: Contributor
timestamp: April 19, 2018, 03:48:57 pm
content: Hi, Guys!I compared signals from 10 to 70 MHz between my RTB2004 (70MHz model), RTB2004 (100MHz model) and checked also with my Lecroy Wavesurfer 422 (no such problems at all).Please can you give me a clue, why the shown amplitude of (sinewave) signals at the R&S RTB2004 decreases at some frequencies and increases at higher frequencies and so on? Just going up and down depending on the frequency - but within the bandwith Limits.This problem does not exist at my Lecroy 422, so this is not caused by the generator (IFR2025).Please see the Pictures attached, where the Signal nearly vanishes at 45MHz (though it is the 100MHz Model). The Scope above is the 70MHz model, below the 100MHz model.I'm asking by myself, what can I really measure then accurately with this scope - or is it just an expensive toy?Thanks a lot in advance, Joseph

author: TheSteve
author_rank: Unknown
timestamp: April 19, 2018, 04:14:24 pm
content: What happens when you add a 50 ohm feed-through termination?

author: Netroman
author_rank: Contributor
timestamp: April 19, 2018, 04:26:09 pm
content: "What happens when you add a 50 ohm feed-through termination?"Thank you so much - the 50Terminator changed it all. This was the Problem, now measurements are stable (Amplitude).Best regards from Austria (OE7JKT).

author: Pinkus
author_rank: Frequent Contributor
timestamp: April 20, 2018, 10:27:59 pm
content: A scope in this price class should come with a switchable 50 Ohm input by standard. We are talking of 6500 Euro (MSO 300 Mhz).... no options included ... another 1400 Euro!

author: maginnovision
author_rank: Super Contributor
timestamp: April 20, 2018, 10:39:43 pm
content: Quote from: Pinkus on April 20, 2018, 10:27:59 pmMaybe, maybe not. All depends on the user. I rarely need 50 ohm so makes little difference to me(I have 2 50 ohm feed through terminators). Other people it's a deal breaker so they should buy something else.

author: jjoonathan
author_rank: Frequent Contributor
timestamp: April 20, 2018, 10:55:20 pm
content: In my case, I bought something else. So it goes.

author: CopperCone
author_rank: Super Contributor
timestamp: April 20, 2018, 11:11:56 pm
content: north koreans put a virus on it

author: Netroman
author_rank: Contributor
timestamp: April 21, 2018, 05:53:42 am
content: I do also own a Lecroy Wavesurfer with switchable 50R inside. My opinion is, that R&S just wanted to bring their name to foreground nothing else.They are used to sell equipment for many 10k USD (think of the popular IMSI-Catchers) - and for these items the options are much more expensive. Since many years they take very much money for their options - even more as the base-units cost.I think, they would have more success, if they would sell the options eg for the RTB2000 series to much lower price for the private users. This would have the effect, that more units would be around and more people/engineers would suggest to buy also the expensive ones for the companies.Because the RTB2000 series lack the direct support of active probes, so these instruments are not the first choice for hi-tec labs.Yes, sometimes less is more - maybe just my opinion...