Author Topic: R&S RTC1002  (Read 3440 times)

0 Members and 1 Guest are viewing this topic.

Offline nctnico

  • Super Contributor
  • ***
  • Posts: 17663
  • Country: nl
    • NCT Developments
Re: R&S RTC1002
« Reply #100 on: September 19, 2019, 07:32:38 am »
I still don't believe the R&S machines and the Sigilant machines are apples to apples when it comes to build quality. Brand name and manufacturing location aside. The BOM of the RTC1002 will certainly be higher.
No. It wouldn't surprise me if the BOM of the Siglent scope is actually higher. Compare these two teardown videos of the scope you bought and a Siglent SDS1104X-E:





There really isn't a difference in component quality here. The cost difference is entirely due to higher software engineering costs in Germany. Designing the hardware for a low end DSO is easy but the software is a huge amount of work.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 
The following users thanked this post: thm_w, 2N3055, Jacon

Offline Mivera

  • Regular Contributor
  • *
  • Posts: 93
  • Country: ca
Re: R&S RTC1002
« Reply #101 on: September 19, 2019, 07:41:23 am »
First of all that's the last gen R&S HMO, although very similar to the RTC.

I watched both videos and the R&S looks superior to me in build quality. And Dave's reaction to several aspects of the build quality of the R&S was very favourable. Drooling over almost every aspect. Then when we come to the software the R&S runs silky smooth. And with a boot up time 3x faster. The rotary knobs are much more sturdy, BNC connectors are gold plated and beefier, expensive high quality molex microfit connectors used exclusively for all internal connections. Power supply caps superior. Silent fan on the R&S, compared to a noisy one which Dave commented sounded horrible. Regarding the PCB itself, you can tell the Siglent is Chinese. Where the ultra clean board on the R&S is German designed, and built in house on the SOTA machines at R&S's own European factory. And based on the standard of excellence of all of the clearly visible components, I think it's safe to assume R&S also used superior MLCC's, resistors, diodes, inductors, and polymer caps on the PCB.

 Watching this video the knobs appear to be very sloppy as well. And the GUI just seems clunky and unrefined compared to the R&S. Well known software glitches aside. 

Sorry guys not sold on the build quality.

« Last Edit: September 19, 2019, 08:47:02 am by Mivera »
 

Offline Mivera

  • Regular Contributor
  • *
  • Posts: 93
  • Country: ca
Re: R&S RTC1002
« Reply #102 on: September 19, 2019, 11:37:19 pm »
I made an unboxing video for the swarms of R&S fanboy's on this forum:

https://youtu.be/8-wgbj-hDow
« Last Edit: September 19, 2019, 11:39:17 pm by Mivera »
 

Online maginnovision

  • Super Contributor
  • ***
  • Posts: 1108
  • Country: us
Re: R&S RTC1002
« Reply #103 on: September 20, 2019, 01:41:18 am »
Looks good, I hope you like it.
 

Offline Mivera

  • Regular Contributor
  • *
  • Posts: 93
  • Country: ca
Re: R&S RTC1002
« Reply #104 on: September 20, 2019, 03:45:35 am »
Thanks! Yes it's great so far. Still figuring it out. I'm pleased to report a noise floor of under 20uV RMS/140uV pp with 50mhz bandwidth. Far exceeds my expectations.

 

Online maginnovision

  • Super Contributor
  • ***
  • Posts: 1108
  • Country: us
Re: R&S RTC1002
« Reply #105 on: September 20, 2019, 03:58:23 am »
Since it has the variable filter you could probably get it even lower if you're working at audio frequencies.
 

Offline Mivera

  • Regular Contributor
  • *
  • Posts: 93
  • Country: ca
Re: R&S RTC1002
« Reply #106 on: September 20, 2019, 04:01:13 am »
Yes that's full bandwidth with the base settings I ordered. And you not only can lower to 20mhz, there's a 5mhz low pass filter, as well as a noise filter that can be enabled. Haven't tried them yet.
 

Online maginnovision

  • Super Contributor
  • ***
  • Posts: 1108
  • Country: us
Re: R&S RTC1002
« Reply #107 on: September 20, 2019, 04:31:04 am »
In acquisition mode and arithmetic it has the variable low pass filter. Says the cutoff is determined by sample rate and can vary from 1/100 sample rate to 1/4 sample rate so I bet you could get it lower than 5MhZ
 

Offline Mivera

  • Regular Contributor
  • *
  • Posts: 93
  • Country: ca
Re: R&S RTC1002
« Reply #108 on: September 20, 2019, 04:35:31 am »
I'll have to play around more. Of course what really matters is how low I can measure with the probes attached. I need to make up some Molex micro fit probe jigs to test my 0.4uV noise supply. Will probably need to do the differential A-B technique with dual probes to get the best results.
 

Offline egonotto

  • Regular Contributor
  • *
  • Posts: 220
Re: R&S RTC1002
« Reply #109 on: September 20, 2019, 04:37:47 am »
Hello,

is this with high resolution?

Have fun with you new scope :)

Best regards
egonotto
 

Offline Mivera

  • Regular Contributor
  • *
  • Posts: 93
  • Country: ca
Re: R&S RTC1002
« Reply #110 on: September 20, 2019, 04:40:28 am »
Thanks. The high resolution mode only extends the range of the screen to beyond the actual size of the screen. Then there's a mode that allows you to pan beyond the borders of the screen for extra viewing area.

Skip to 33:30 in this video to see how it works:

https://youtu.be/q_FBwu2K7j0
« Last Edit: September 20, 2019, 04:42:56 am by Mivera »
 

Offline Mivera

  • Regular Contributor
  • *
  • Posts: 93
  • Country: ca
Re: R&S RTC1002
« Reply #111 on: September 20, 2019, 06:29:02 am »
I suppose it's also worth mentioning that noise floor measurement was with a 1Mohm input. From what I've been reading a 50ohm input reduces noise quite a bit. But for some reason they got rid of the 50ohm option for the RTC. That's a shame.
 

Offline nctnico

  • Super Contributor
  • ***
  • Posts: 17663
  • Country: nl
    • NCT Developments
Re: R&S RTC1002
« Reply #112 on: September 20, 2019, 11:26:45 am »
Still an external low noise amplifier may give you better results. For the low V/div settings a DSO has to amplify the signal so this will add extra noise. In theory the noise performance will be better at V/div settings which require no amplification and least attenuation. I recon that is in the 20mV/div to 100mV/div range (with a 1:1 probe).
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 
The following users thanked this post: thm_w

Offline Mivera

  • Regular Contributor
  • *
  • Posts: 93
  • Country: ca
Re: R&S RTC1002
« Reply #113 on: September 20, 2019, 02:27:51 pm »
Can you send a link to one of the amplifiers that you're talking about?
 

Offline Mivera

  • Regular Contributor
  • *
  • Posts: 93
  • Country: ca
Re: R&S RTC1002
« Reply #114 on: September 20, 2019, 04:04:39 pm »
Another shot @ 20mhz bandwidth. 1mohm input with nothing terminated on it:

 

Offline Mivera

  • Regular Contributor
  • *
  • Posts: 93
  • Country: ca
Re: R&S RTC1002
« Reply #115 on: September 20, 2019, 11:07:52 pm »
Still don't know what I'm doing. But was able to get down to 40uV RMS noise out of my lowest noise supply using a single probe method. But that noise was mostly interference. I still haven't figured out how to tell what frequency the noise spikes are at.

 

Offline thm_w

  • Super Contributor
  • ***
  • Posts: 1380
  • Country: ca
Re: R&S RTC1002
« Reply #116 on: September 20, 2019, 11:38:04 pm »
There is no load, so may not be representative of in-use values.

Try measuring the output of the RAC05 at 1A load and you should be getting 60mV p-p (or a bit less due to larger capacitance): https://recom-power.com/pdf/Powerline_AC-DC/RAC05-K.pdf
If its significantly higher or lower, you know something is wrong with the measurement setup.
 

Offline Mivera

  • Regular Contributor
  • *
  • Posts: 93
  • Country: ca
Re: R&S RTC1002
« Reply #117 on: September 20, 2019, 11:45:53 pm »
I know theres no load. But the issue isn't that theres no load. It's interference anyways. The RAC-05 SMPS is being filtered by multiple stages of regulation so the ripple is no longer 60mV p-p. Under full load the actual noise of this supply under 100khz Is only 0.4uV. The supply is already a proven design, I'm just using it as a reference for the lowest noise I'm capable of measuring with this setup.
 

Offline Mivera

  • Regular Contributor
  • *
  • Posts: 93
  • Country: ca
Re: R&S RTC1002
« Reply #118 on: September 21, 2019, 12:34:39 am »
 

Offline thm_w

  • Super Contributor
  • ***
  • Posts: 1380
  • Country: ca
Re: R&S RTC1002
« Reply #119 on: September 21, 2019, 12:48:14 am »
I know theres no load. But the issue isn't that theres no load. It's interference anyways. The RAC-05 SMPS is being filtered by multiple stages of regulation so the ripple is no longer 60mV p-p. Under full load the actual noise of this supply under 100khz Is only 0.4uV. The supply is already a proven design, I'm just using it as a reference for the lowest noise I'm capable of measuring with this setup.

I suggested to measure the output of the RAC-05, which would be before the filtering you've added.
 

Offline Mivera

  • Regular Contributor
  • *
  • Posts: 93
  • Country: ca
Re: R&S RTC1002
« Reply #120 on: September 21, 2019, 12:52:31 am »
I could do that. But I have a far more comprehensive datasheet on my Sanken supply with scope plots and everything. Just need to find them on my computer as the HWB series was discontinued and the detailed datasheet’s are no longer available to download. It’s also around 600uV RMS ripple, so would be better to test the 1mV division.
 

Offline Mivera

  • Regular Contributor
  • *
  • Posts: 93
  • Country: ca
Re: R&S RTC1002
« Reply #121 on: September 21, 2019, 05:22:53 pm »
I measured a bunch of supplies and got the results that were expected. I'm quite shocked how good of measurements I'm able to get from a single probe. Especially since the scope is plugged into a power bar with a noisy PC, monitor and other things plugged into it. I have LED lights in the room, and who knows what else that could interfere. But in spite of all of this I'm still able to measure down to 40uV RMS with a single probe. Which is far better than what I was expecting to be able to do before purchasing this scope. This scope is extremely immune to EMI, as the measurements of the scope itself are lower than any of the Chinese scopes with a 50ohm termination on the input, even without a 50ohm termination on the BNC input. I still haven't figured out how to fine tune the special filters, zoom in and use all of the other useful features.

 I must say I'm glad I bought this scope before starting this thread or I may have not bought it.
 

Online maginnovision

  • Super Contributor
  • ***
  • Posts: 1108
  • Country: us
Re: R&S RTC1002
« Reply #122 on: September 21, 2019, 05:30:57 pm »
I think the real interesting thing is that most people don't regret their purchase. At least not for years since most scope aren't bad. Just make sure you learn and use it as much as you can before return period is over so you have no regrets later. That way you'll either be happy with your purchase or be able to try something else. To be perfectly honest for the price difference I'd probably get the RTC1K-COM2. You may not need it all now but maybe later you would... Hard for me to say what your needs will be. If nothing else resale value would be better.
 

Offline Mivera

  • Regular Contributor
  • *
  • Posts: 93
  • Country: ca
Re: R&S RTC1002
« Reply #123 on: September 21, 2019, 05:38:53 pm »
Well It has already proven in actual use that it's been able to take far lower noise measurements than I expected. And nobody has been able to share data that other scopes anywhere near the price point have been able to measure even lower noise of both the machine itself, and actual measurements with a probe. All I ever read about is how much of a nightmare it is trying to measure under 200-300uV with a single standard probe. When it was a breeze for me to measure down to 40uV. For example my PCB guy has a Rigol, and this is the best he could get from my same Purecharge supply in the attachment. And this is after hours of messing around. Look at the pink channel

Regarding the RTC1K-COM2 package, it is a great deal. However after thinking hard it is $700 more CND, and I can already do everything I need to do with this scope. If down the road I need more capabilities, I will buy a higher end R&S scope and put it in a different station. This one will be perfect for full time use in the power supply QC station for decades.
« Last Edit: September 21, 2019, 05:41:48 pm by Mivera »
 

Online maginnovision

  • Super Contributor
  • ***
  • Posts: 1108
  • Country: us
Re: R&S RTC1002
« Reply #124 on: September 21, 2019, 06:10:53 pm »
Yea, the 1054Z is not known to be especially low noise. I've had trouble checking... anything with one(always seems to be small signal stuff and I just take another scope with me). It's an 8 bit scope with software magnified lower ranges though, you can't expect too much from it down low. I'm glad you're liking your new scope. To check really low noise stuff you still want at least a single ended low noise amplifier or alternatively just a decent multimeter if you don't need to characterize the noise.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf