Thank you for sharing info for a relatively low cost and effort test rig for capacitors. This setup shuld work well for troubleshooting marginal components in a RF oscillator circuit ( tested out of circuit of course) as well as your intended ESR measurement function.
Great! I did not expected the response of the resistor rising at so lower frequency.. I used two resistors to mod an osciloscope broke 50 ohm input and in my tests the response was equal to the other original channel up to 350meg.
This is great! Here's a suggestion for your next video: Show how to determine the value of a capacitor given an inductance of known value and using the VNA to find the resonant frequency. From there, speculate on how to make this measurement with a PIC micro :)
Great video, thankyou. The datasheet lists the VNA frequency range as 10Mhz to 1GHz but you are doing a sweep from 100kHz. I'm tempted to get one but 10MHz is restrictive. Is there a way to enable 100kHz?
Hello. Great video and explanation! I'm amazed with you being able to sweep from as low as 100 kHz. The analyzer's datasheet states a range of 10 MHz-1.5Ghz. Did you do anything special to enable going as low as 100 kHz? Or is it a datasheet errata? Thank you!
The main frequency limitation is on the input directional coupler used to measure S11. It is not happy below 10 MHz. However S21 works well down to 1 MHz and is usable down to 100 KHz.
@@Chris_Grossman Thank you very much! 1 MHz... interesting... The tracking generator (according to datasheet) works from 5 MHz up. Have tried to go down to 1 MHz?
Love your SVA presentations ! Not being a mathematician I can't work out how you arrive at a capacitance value given the ESR. Could you elaborate on the calculation for the 0.1uF example in your presentation so a simple soul can understand what is going on? Many thanks.
Not as I have shown. The problem is the parasitic capacitance from any fixture or probes will preclude accurate measurements. In my experience you can typically measure down to 10pF, if you are very careful about minimizing fixture/probe parasitics and do a good cal you can get down just below 1pF. If you are measuring on-chip devices on a IC wafer in a well designed test structure, have on-wafer calibration structures, GSG RF probes, and a very accurate network analyzer that goes high enough in frequency (into the GHz region) you can get believable measurements down to ~10fF and less accurate measurements down to about 1fF
one thing that people keep ignoring, including this video, is that ESR is NOT an actual physical resistor and its value is highly frequency dependent. So with this method you are ONLY calculating the ESR at that resonant frequency which is not that useful specially when it comes to electrolytics and their application which is normally low pass filtering at low frequencies.
Do you have some updated links for the ESR conversion table and graphs please? The links provided seem to be unavailble now. Thanks for a very interesting video!
Replying to myself, hehehe, it's ok, I used your formula at timestamp 10:34 to make a spreadsheet and now I can see any value I want, and the graph at that timestamp is the one I was after anyway. Job done :o)
@@Chris_Grossman The website chrisgrossman.com simply doesn't respond, whatever browser I use, it just times out. Maybe you can see it from within your network, or maybe you have a cached copy on your machine, but it doesn't seem to be accessible from the web. I've built my own spreadsheet for it now, but anyone else wanting to access the link may run into the same problem I'm seeing from here.
@@GigglingGobby it works from my cell phone on the cell network. I logged into another server in a remote facility and it works from there. I tried it using a VPN and it works. I tried using multiple browsers on both Linux and windows systems and all work. I checked the log and I can see it serving content.
@@Chris_Grossman Thanks for testing that. I tried 4 browsers on 2 machines, and then with my mobile phone on Wifi on the same landline broadband and then with WiFi disconnected so I was using a completely different (mobile) ISP, still nothing. However, a couple of my friends managed to see your website, so I tried again but this time with VPN so it would look to the server like I was in another country and it instantly connected! Something's stopping my landline's and mobile's IP addresses (in the UK) from accessing the server where the website is hosted. No idea what's going on there, but I got there in the end :o)
Very nice explanation & demonstrations! Thank you for sharing your knowledge, please continue to do so.
Thank you for sharing info for a relatively low cost and effort test rig for capacitors. This setup shuld work well for troubleshooting marginal components in a RF oscillator circuit ( tested out of circuit of course) as well as your intended ESR measurement function.
Hi! How to detect a short-circuited coil in a choke with NanoVNA? Thank you!
Thanks Chris for sharing this interesting video
You're welcome
Excellent video - thanks Chris!
I hope it was helpful for you.
Great!
I did not expected the response of the resistor rising at so lower frequency..
I used two resistors to mod an osciloscope broke 50 ohm input and in my tests the response was equal to the other original channel up to 350meg.
This is great! Here's a suggestion for your next video: Show how to determine the value of a capacitor given an inductance of known value and using the VNA to find the resonant frequency. From there, speculate on how to make this measurement with a PIC micro :)
Can you measure Elkos ESR at 100kHz with the VNA? It's out the same like a dedicated ESR meter?
Great video, thankyou. The datasheet lists the VNA frequency range as 10Mhz to 1GHz but you are doing a sweep from 100kHz. I'm tempted to get one but 10MHz is restrictive. Is there a way to enable 100kHz?
Hello. Great video and explanation! I'm amazed with you being able to sweep from as low as 100 kHz. The analyzer's datasheet states a range of 10 MHz-1.5Ghz. Did you do anything special to enable going as low as 100 kHz? Or is it a datasheet errata? Thank you!
The main frequency limitation is on the input directional coupler used to measure S11. It is not happy below 10 MHz. However S21 works well down to 1 MHz and is usable down to 100 KHz.
@@Chris_Grossman Thank you very much! 1 MHz... interesting... The tracking generator (according to datasheet) works from 5 MHz up. Have tried to go down to 1 MHz?
Love your SVA presentations ! Not being a mathematician I can't work out how you arrive at a capacitance value given the ESR. Could you elaborate on the calculation for the 0.1uF example in your presentation so a simple soul can understand what is going on? Many thanks.
My next video will be how to measure the impedance, capacitance, and correct for fixture parasitics.
Very helpful. Where can I get the chart and/or your equation for ESR?
Expand the video description comments above which are just below the video. All of the links are there.
@@Chris_Grossman Thanks! It took a while to figure out how to find it...
Thanks for the interesting video. Do you think it would be possible to measure extremely small capacitance such as femtofarad or even lower?
Not as I have shown. The problem is the parasitic capacitance from any fixture or probes will preclude accurate measurements.
In my experience you can typically measure down to 10pF, if you are very careful about minimizing fixture/probe parasitics and do a good cal you can get down just below 1pF.
If you are measuring on-chip devices on a IC wafer in a well designed test structure, have on-wafer calibration structures, GSG RF probes, and a very accurate network analyzer that goes high enough in frequency (into the GHz region) you can get believable measurements down to ~10fF and less accurate measurements down to about 1fF
@@Chris_Grossman Thanks very much for your reply. And how much do you think such accurate network analyser would cost?
one thing that people keep ignoring, including this video, is that ESR is NOT an actual physical resistor and its value is highly frequency dependent. So with this method you are ONLY calculating the ESR at that resonant frequency which is not that useful specially when it comes to electrolytics and their application which is normally low pass filtering at low frequencies.
Do you have some updated links for the ESR conversion table and graphs please? The links provided seem to be unavailble now. Thanks for a very interesting video!
Replying to myself, hehehe, it's ok, I used your formula at timestamp 10:34 to make a spreadsheet and now I can see any value I want, and the graph at that timestamp is the one I was after anyway. Job done :o)
The links work. Try again.
@@Chris_Grossman The website chrisgrossman.com simply doesn't respond, whatever browser I use, it just times out. Maybe you can see it from within your network, or maybe you have a cached copy on your machine, but it doesn't seem to be accessible from the web. I've built my own spreadsheet for it now, but anyone else wanting to access the link may run into the same problem I'm seeing from here.
@@GigglingGobby it works from my cell phone on the cell network. I logged into another server in a remote facility and it works from there. I tried it using a VPN and it works. I tried using multiple browsers on both Linux and windows systems and all work. I checked the log and I can see it serving content.
@@Chris_Grossman Thanks for testing that. I tried 4 browsers on 2 machines, and then with my mobile phone on Wifi on the same landline broadband and then with WiFi disconnected so I was using a completely different (mobile) ISP, still nothing. However, a couple of my friends managed to see your website, so I tried again but this time with VPN so it would look to the server like I was in another country and it instantly connected! Something's stopping my landline's and mobile's IP addresses (in the UK) from accessing the server where the website is hosted. No idea what's going on there, but I got there in the end :o)
Upvoted for the ubiquitous dog hair.
Just measured esr, in circuit, on S11 in series, with nanovna.
Great job!!
Thank you
I'd put a wire jumper between the test fixture pins to do my 'through' cal.
The trough wire is part of the fixture. The shunt measurement is from the through to ground.