The RBW can only be achieved by manually setting the sample rate in the menu.
-snip
1) link to compressed bin file 100MSa @ 2GSa/s (size is about 95MB) : https://file.io/su83ZcbhPr4d
We have the same generator:
Is there a way, to create a math formula, so one could easily see, what the duty cycle (yellow) roughly is?
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The commonly agreed industry standard for the maximum acceptable input VSWR is 1.5:1, which is equivalent to 14 dB return loss.
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I've never heard of such a standard. Could you provide a reference? If you are making measurements, 1.5 seems really high.
Looking at the manual for my LeCroy 7200, they spec the VSWR at 1.2, BW is 4GHz with a 125pSec transition for 50mV and up. Isolation is 60dB min at 1GHz.
A VSWR of less than 1.5:1 is ideal, a VSWR of 2:1 is considered to be marginally acceptable in low power applications where power loss is more critical …
Input VSWR : input frequency ≤ 500 MHz 1.25 (meas.); input frequency > 500 MHz 1.4 (meas.)
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The commonly agreed industry standard for the maximum acceptable input VSWR is 1.5:1, which is equivalent to 14 dB return loss.
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I've never heard of such a standard. Could you provide a reference? If you are making measurements, 1.5 seems really high.
Looking at the manual for my LeCroy 7200, they spec the VSWR at 1.2, BW is 4GHz with a 125pSec transition for 50mV and up. Isolation is 60dB min at 1GHz.
I have no reference to such a standard – my statement is based solely on the impression left by various RF literature, experience and common sense. Sorry if it has been misleading.
At least one example, showing that I’m not the only one who thinks 1.5:1 is the limit of acceptable (some might call it ideal) VSWR, can be found here:
https://www.ahsystems.com/notes/VSWR-return-loss-sheet.phpQuoteA VSWR of less than 1.5:1 is ideal, a VSWR of 2:1 is considered to be marginally acceptable in low power applications where power loss is more critical …
Very few oscilloscopes have the input return loss / VSWR specified; one of the few exceptions was the now discontinued 2 GHz R&S RTE. From the data sheet Version 16.01:QuoteInput VSWR : input frequency ≤ 500 MHz 1.25 (meas.); input frequency > 500 MHz 1.4 (meas.)
I take from this, that a company, that is renowned to be an RF-specialist since 1933, has no problems specifying a VSWR of 1.4:1 for frequencies >500 MHz on an instrument that isn’t exactly a cheap low-end product. There exists no VSWR-specification for its successor, the MXO5, anymore…
Finally, the common-sense part: A VSWR of 1.5:1 means 4 % reflected power, i.e. 4 % power loss at the receiver end (scope input). That’s 0.17 dB = ~2% voltage error. It is less than the DC-accuracy specification of most oscilloscopes.
As can be seen from my measurements, the 500 (actually 570) MHz SDS2000X HD provides a VSWR of <1.25:1 up to ~750 MHz. That should be in line with your expectations based on the LeCroy 7200.
So now we can officially say that there is some margin of improvement in FFT performance, could you "disclose" if we will see something in regard with the incoming FW release?
Is there a way, to create a math formula, so one could easily see, what the duty cycle (yellow) roughly is?
A "Measurement Track" (section 18.5 of the manual) should do what you want: Calculates time-dependent measurements within one capture and plots them like a trace.
Thanks for the response. It could very well be my lack of any common sense and experience causing my confusion.
Thanks for the response. It could very well be my lack of any common sense and experience causing my confusion.
No need to be sarcastic.
I thought it was clear that I was talking about oscilloscopes and not power meters, which commonly have an order of magnitude better accuracy. Consequently, I would also prefer a VSWR of 1.05 for the power meter.
I thought it was clear that I was talking about oscilloscopes and not complete measurement setups. Nowhere did I state that a better VSWR could not be beneficial at times, and that it could not be achieved by adding an inline attenuator – even though in practice I’ve more often wanted to improve the output impedance match of a generator than the input match of an oscilloscope – but that’s just me.
A revised summary of this thread together with some new content in a PDF can be found here:
https://www.eevblog.com/forum/testgear/sds800x-hd-review-demonstration-thread/msg5422823/#msg5422823
While a VSWR of 1.5 may be a good guideline when talking about antennas, it's not something I have ever considered when making a measurement in the lab. Certainly not a standard. Rather, I treat each measurement as a unique problem.