If I'm reading the HP8591e spec sheet correctly the amplitude accuracy is ± 0.3 dB at -20 dBm; 0 to -59.9 dBm: ± (0.3 dB + 0.01 x dB from -20 dBm) . The Rigol has an 8 bit ADC and the spec sheet says ± 3% of full scale. It will take a little math to figure out which one (based on the spec sheets) is the more accurate tool. And of course this is for calibrated tools. However, the calibration quote for my HP8591e was more than 2X what I paid for the whole SA.
Hey man! I came here just to tell you that I finally tested using CATV splitters with 75 ohm coax to phase antennas on VHf. It works for me with 5 watts of power. 5-1000 MHz two way splitters, IKUSI brand. 3,7 dB loss per channel I asume 3dB is dividing the signal by two plus 0,7 insertion loss. You could make some video to test how much power these kind of splitters can stand, I only have a handheld radio with 5W. Antennas are 50 ohm, coax cut to adequate length to match impedance on input. VSWR 1.0-1.1
The procedure to convert dBm to dBV for any characteristic impedance is the following: 1) Convert dBm to dBW (1dBW = 30dBm or 1dBm=-30dBW) 2) Add the characteristic impedance described in dB(Ω) (dB(Ω) -> 10xlog(Characteristic impedance)) 3) done Tips: 50Ω -> ≈17dB(Ω) 75Ω -> ≈18.75dB(Ω) 400Ω -> ≈26dB(Ω) Example: 24dBm to dBV @ 75Ω 1) 24dBm = -6dBW (24dBm-30dB) 2) -6dBW = 12.75dBV (-6dBW+18.75dB(Ω)) The constant( -13) of this video calculate as -30+17=-13, which -30 is the conversion factor for dBm to dBW, and 17 the presentation of 50Ω in dB(Ω).
Using the built in FG in the MSO5000, I got a clear picture in FFT @ 25MHz But @ RBW of 200Hz. I was going to post pictures but you can't here. Is it possible using patreon? I have some questions about my HP 8590A Spectrum Analyzer. If you can help me with it I will become a Patron. Moneys tight but you would be worth it your channel rocks! I have learned a lot.
18:10? You can actually comfortably resolve 1.9 GHz peaks with this scope FFT with a 200 kHz RBW. Search "RIGOL MSO5000 a 1.9GHz?" on youtube for an example (at 9:36 on that video).
The FFT on the latest Rigol scopes, including MSO 8000, 7000, and 5000 is slow, and feature-incomplete. It's a pity that developers at Rigol seem to be mainly focused on the future hardware/software, and have little time for improving the software/firmware for the existing hardwares.
@@qwaqwa1960 On Rigol, it doesn't display scales on the vertical axis. It doesn't allow manual setting of RBW. If you use cursor function to make measurements on the FFT view, the rotary encoder is poorly implemented in firmware that it jumps like crazy sometimes.
@@qwaqwa1960 Could be ive been lucky but i can't recall ever having a known bug on a Tek Scope. Compared to Rigol and Siglent their quality is way far ahead. I have a mature rigol mso4000 scope with several bugs that they never bothered to fix. As with all things you get what you pay for and the truth of the matter is i can't afford a tek scope. I know the bugs and work around
If I'm reading the HP8591e spec sheet correctly the amplitude accuracy is ± 0.3 dB at -20 dBm; 0 to -59.9 dBm: ± (0.3 dB + 0.01 x dB
from -20 dBm) . The Rigol has an 8 bit ADC and the spec sheet says ± 3% of full scale. It will take a little math to figure out which one (based on the spec sheets) is the more accurate tool. And of course this is for calibrated tools. However, the calibration quote for my HP8591e was more than 2X what I paid for the whole SA.
HP 32S...Great calculator. I've got that one and a HP 15C RPN...(Reverse Polish Notation)
Hey man!
I came here just to tell you that I finally tested using CATV splitters with 75 ohm coax to phase antennas on VHf.
It works for me with 5 watts of power.
5-1000 MHz two way splitters, IKUSI brand. 3,7 dB loss per channel I asume 3dB is dividing the signal by two plus 0,7 insertion loss.
You could make some video to test how much power these kind of splitters can stand, I only have a handheld radio with 5W.
Antennas are 50 ohm, coax cut to adequate length to match impedance on input. VSWR 1.0-1.1
Merci.
Around 6:52 you made Ch 1. Disappear. If I Press the channel 1 button, it disappears but so does the FFT. Please explain how you did this, thanks!
press for a very short time channel 1 button then the time domain signal disappears.
Thx so much for sharing
At 4:45, IF R=50 Ohm, then dBm-13=dBV. For other loads (characteristic impedances), the difference will be different.
that is certainly true
The procedure to convert dBm to dBV for any characteristic impedance is the following:
1) Convert dBm to dBW (1dBW = 30dBm or 1dBm=-30dBW)
2) Add the characteristic impedance described in dB(Ω) (dB(Ω) -> 10xlog(Characteristic impedance))
3) done
Tips:
50Ω -> ≈17dB(Ω)
75Ω -> ≈18.75dB(Ω)
400Ω -> ≈26dB(Ω)
Example: 24dBm to dBV @ 75Ω
1) 24dBm = -6dBW (24dBm-30dB)
2) -6dBW = 12.75dBV (-6dBW+18.75dB(Ω))
The constant( -13) of this video calculate as -30+17=-13, which -30 is the conversion factor for dBm to dBW, and 17 the presentation of 50Ω in dB(Ω).
@@samtzam3774 edadocs.software.keysight.com/kkbopen/converting-dbm-to-dbv-in-a-50-ohm-system-588265460.html
You can see the menu entry "Unit dBm/dBV" e.g. at 18:37 ff in the upper right - so can't you just switch to dBm?
nope
Try 8192 bins plus a Kaiser Window for 8192 bins and 10.056 and see what that yields.
Can you use the FFT for EMI Far field and Close field test?
oscilloscopes are not really optimized for spectral work but yes. Expensive spectrum analyzers these days have FFT math in them too
I'm pretty much ready to buy one of these, my only concern is whether or not the hack still works.
The hack still works. I would recommend reading the thread in the test-equiment thread in the eevblog forum.
Using the built in FG in the MSO5000, I got a clear picture in FFT @ 25MHz But @ RBW of 200Hz. I was going to post pictures but you can't here. Is it possible using patreon? I have some questions about my HP 8590A Spectrum Analyzer. If you can help me with it I will become a Patron. Moneys tight but you would be worth it your channel rocks! I have learned a lot.
on my UA-cam user page, click the about tab, then you can view my email address
18:10? You can actually comfortably resolve 1.9 GHz peaks with this scope FFT with a 200 kHz RBW. Search "RIGOL MSO5000 a 1.9GHz?" on youtube for an example (at 9:36 on that video).
here is a video showing 1GHz: ua-cam.com/video/egUCC1rvau0/v-deo.html
The FFT on the latest Rigol scopes, including MSO 8000, 7000, and 5000 is slow, and feature-incomplete. It's a pity that developers at Rigol seem to be mainly focused on the future hardware/software, and have little time for improving the software/firmware for the existing hardwares.
And that's different from Tek, KeeShite, LeCrap... how?
@@qwaqwa1960 On Rigol, it doesn't display scales on the vertical axis. It doesn't allow manual setting of RBW. If you use cursor function to make measurements on the FFT view, the rotary encoder is poorly implemented in firmware that it jumps like crazy sometimes.
@@qwaqwa1960 Could be ive been lucky but i can't recall ever having a known bug on a Tek Scope. Compared to Rigol and Siglent their quality is way far ahead. I have a mature rigol mso4000 scope with several bugs that they never bothered to fix. As with all things you get what you pay for and the truth of the matter is i can't afford a tek scope. I know the bugs and work around
Hp seems simpler to operate
absolutely