For a newbie, seeing the process of: attaching, setting up the nano parameters, reading and observation is really nice. Multiple examples are a great help. You operate with such confidence and verve. Well done.
Most of those filters are designed for a terminating impedance other than 50 ohms, hence the odd passband shapes you are seeing. It might be interesting to experiment with feeding them through series resistors so they see a higher impedance. That will likely clean up the passband shape on most of them. Start with a few hundred ohms on both ends. The 880 filter is obviously designed to work in a 50 ohm system.
I was about to comment on that - proper terminations, without which the passband is distorted (unless, of course, they are Nanovna’s 50 ohms) - when I read your comment. Congrats.
the 45M is a crystal filer and definitely not matched to 50 ohm hence the very crappy response. The 114M is probably an inverse Chebyshev filter. It could also be a Bessel filter (if you could measure the phase response, it would show).
calibration is done over start/stop frequencies. so if the various filters are between those frequencies then you are fine. there maybe only 400 calibration points between start and stop.
Just learning about the nanovna.. very kewl little bugger.. I have an H and it doesn’t connect to the pc,, shows a malfunction,,not recognized, Windows 7 or 10.. doesn’t matter, my question is is there a way to update the firmware even though it isn’t recognized by the USB ports,. It works from the screen. Just would be nice to connect it to the pc like my other H does,,thanks
`So, I assume that you can look at IF cans for tube and transistor radios in the same manner with similar reliable results? Thanks for yet another awesome video. I spend half my time on the internet watching your videos.
Does the NANOVNA H describe a specific product, or is it a general term. I would like to get one of these, and I want the product you are using here. When I look at these on the internet there are so many. I will also be using the product for filter applications.
@@IMSAIGuy I am trying to figure out how to connect a reflection bridge to an older VNA. I suppose DUT to the antenna and SWR output to the input of the VNA. When not connecting an antenna there seems to be no throughput thru the bridge. I thought from input to output that should have hardly losses.
@@egbertgroot2737 I'm not sure of your setup. normally a VNA has a bridge built in so why have an external one? do you have a VNA or scalar network analyzer? it it a real bridge or a directional coupler?
It is very difficult to obtain some of these filters In my spectrum analyzer CMU200 R&S Yesterday he passed away on the RXTX board The filter Murata DFC3R836P025HHD BPF 836MHZ That's why my spectrum analyzer is like a doorstop right now I did not find the filter for sale at any supplier :(
I am very interested in the 880MHz filter. Do you have any more information? Who makes it? I understand that it is three resonator sections but I don't understand if it only has orifices. Due to the dimensions they are very small even for 880MHz. I really wish I could build a similar one. I appreciate more information to get one of these.
it depends on application. sometimes you need the signal to stay constant and so you need a flat response. sometimes it is more important to have steeper sides, this usually results in dips and peaks
For a newbie, seeing the process of: attaching, setting up the nano parameters, reading and observation is really nice. Multiple examples are a great help. You operate with such confidence and verve. Well done.
Glad you enjoyed it!
Most of those filters are designed for a terminating impedance other than 50 ohms, hence the odd passband shapes you are seeing. It might be interesting to experiment with feeding them through series resistors so they see a higher impedance. That will likely clean up the passband shape on most of them. Start with a few hundred ohms on both ends. The 880 filter is obviously designed to work in a 50 ohm system.
I was about to comment on that - proper terminations, without which the passband is distorted (unless, of course, they are Nanovna’s 50 ohms) - when I read your comment. Congrats.
You sure are having lots of fun with these two devices! I am learning so much that my head hurts now. Thanks, Carl
That filter with the floatin pin would be a varactor diode in it to adjust the capacitance for fine tuning
the 45M is a crystal filer and definitely not matched to 50 ohm hence the very crappy response. The 114M is probably an inverse Chebyshev filter. It could also be a Bessel filter (if you could measure the phase response, it would show).
Assume this is a DECT IF Filter. SAW.
Exactly.
Really enjoy the VNA filter analysis!
Filter from a cellphone. 880 is a cellular band.
Possibly from a trunked radio in 800 MHz.
Thank you for your excellent videos. The knowledge you share is helping is helping curious ham radio operators advance. 73 Bret/AC0AE
That 880MHz and 45MHz filter were probably removed from an old Motorola analogue cell phone. One of the car transportable type 4800x.
are there 2 traces? how set channel 1 then channel 2 on the new nano vnas? I keep getting logmag confused with actual signal strength.
Do you need to do a calibration before you measure each filter?
calibration is done over start/stop frequencies. so if the various filters are between those frequencies then you are fine. there maybe only 400 calibration points between start and stop.
Hi, nice video! But I wonder if nanovna should be calibrated on each frequency of DUT?
depends on what accuracy you want. it is more important on S11 and not so much for S21 measurements
Just learning about the nanovna.. very kewl little bugger.. I have an H and it doesn’t connect to the pc,, shows a malfunction,,not recognized, Windows 7 or 10.. doesn’t matter, my question is is there a way to update the firmware even though it isn’t recognized by the USB ports,. It works from the screen. Just would be nice to connect it to the pc like my other H does,,thanks
nanovna.com/?page_id=103
`So, I assume that you can look at IF cans for tube and transistor radios in the same manner with similar reliable results? Thanks for yet another awesome video. I spend half my time on the internet watching your videos.
yes, cans are just LC circuits but with a transformer. thanks for watching
@@IMSAIGuy Thanks. I'm going to give this a shot.
Could the nanovna be used to confirm the function of a two band diplexer?
th-cam.com/video/TbEK4v_3Xuo/w-d-xo.html
Great video, thanks! I really like how you scavenge and repurpose parts. I’m going to start doing the same.
Can you do a tutorial on setting up the NANO VNA from scratch to do these types of tests. I'd like to tune band pass filters for ham radio use. Thanks
Try this. th-cam.com/video/f-qJIjaFIrs/w-d-xo.html
Does the NANOVNA H describe a specific product, or is it a general term. I would like to get one of these, and I want the product you are using here. When I look at these on the internet there are so many. I will also be using the product for filter applications.
It was the 4" screen version: www.banggood.com/custlink/K3GhjN9JZf
Do you have a video on how to measure an antenna using a VNA?
yes I have many videos measuring antennas. I have a playlist for the NANOVNA. here is one video:
th-cam.com/video/u3EAZHIjo_A/w-d-xo.html
@@IMSAIGuy I am trying to figure out how to connect a reflection bridge to an older VNA. I suppose DUT to the antenna and SWR output to the input of the VNA. When not connecting an antenna there seems to be no throughput thru the bridge. I thought from input to output that should have hardly losses.
@@egbertgroot2737 I'm not sure of your setup. normally a VNA has a bridge built in so why have an external one? do you have a VNA or scalar network analyzer? it it a real bridge or a directional coupler?
@@egbertgroot2737 this video may help you
go to 24:42
th-cam.com/video/j4mLM1l5M7A/w-d-xo.html
@@IMSAIGuy I have 2 measuring devices that i try to use for this measurement: HP 4195A or HP 8711C. Are these VNA's or scalar network analyzers?
ok what setup for pass thru? s11? s21? where is the second trace? how set traces, format etc?
This thing makes little sense to me.
I have a playlist for nanovna
It is very difficult to obtain some of these filters
In my spectrum analyzer CMU200 R&S
Yesterday he passed away on the RXTX board
The filter
Murata DFC3R836P025HHD
BPF 836MHZ
That's why my spectrum analyzer is like a doorstop right now
I did not find the filter for sale at any supplier :(
I am very interested in the 880MHz filter. Do you have any more information? Who makes it? I understand that it is three resonator sections but I don't understand if it only has orifices. Due to the dimensions they are very small even for 880MHz. I really wish I could build a similar one. I appreciate more information to get one of these.
www.mwrf.com/technologies/components/article/21846398/6-types-of-resonators-used-across-the-rfmicrowave-universe
@@IMSAIGuy Thank you so much !!!!!!
Is it generator and spectrum analyzer?
yes it can output too.
45 MHz can is probably an IF filter.
what is the difference between a concave flat and a rounded one
it depends on application. sometimes you need the signal to stay constant and so you need a flat response. sometimes it is more important to have steeper sides, this usually results in dips and peaks
they don't have the skill set to do that RF stuff, they are just digital dummies.😁
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