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I never intended to add a Smith chart to my S-parameter plotter. I can appreciate how useful they must have been before computers, but I don't see their value today. A computer program, especially one with automatic optimization, can make quick work of a complex matching problem. However, since I see references to Smith charts here all the time, before I dismiss them I thought I should ask why people use them. What do they offer that rectangular plots versus frequency don't? https://k6sti.neocities.org/splot Brian
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Hello, Homemade BLUE bowtie antenna vs factory made BLACK whole board with the same bowtie antenna. Over 300 - 330 MHz range I am seeing some ~20 change in reactance with the home made antenna and ~50 ohm with the factory made. Also the resistance is 7-8 times greater for the factory made antenna, also varying much more. Sames: - placement of the antenna - calibration place, cables and others related (*) Diffs: - calibration range: 300-330 for home made vs. 235-395 for factory made - (*) connection to home made antenna through SMA connectors vs. direct soldering for the factory made antenna; - calibrated with standards for home made vs. with wire / nothing / two 100 ohm resistors measured at 50.5 ohms with DMM Is it normal to see such large measurement differences ? Thank you
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NANO APP
2
I downloaded the Nano VNA App from the website. And tonight I tried to use it unsuccessfully. I had connected the vna to my laptop > selected com port 1 for the usb, and didn't get a response indicating a sweep after going through the steps for calibration. I have a full wave 40m to 10m skywire loop that I use. I'm just wondering what I may have missed during the setup to the laptop. I have a presentation to do very soon and I hope to demonstrate it. DE KD5SMF, MARK
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H4 + nanovna-saver calibration
21
I use nanovna-saver with my H4 because it aggregates several useful functions for operating, storing, printing, and exporting measurements. I am confused about the calibration done from nanovna-saver. I know I can load and save calibrations on my PC as files. This works and I use it all the time. I wanted to take the H4 out to the yard and do measurements at the antenna after I calibrated with nanovna-saver. It seems that it did not retain the calibration. I don't remember if I had turned the H4 off, then back on, but the results were different when I then brought out my laptop and loaded my calibration file. Everything seemed to measuring correctly, after that. So I have some questions; 1) What is the persistence of calibration done through nanovna-saver? I.e., does it persist if the USB cord is disconnected and the H4 is taken for mobile measurements? 2) Is the calibration done by nanovna-saver dependent on the calibration done by the H4's internal cal? For instance, say memory #0 on the H4 has a bad calibration stored. Since this is the default used by the H4 when it boots up, will it corrupt the calibration done in nanovna-saver. Does nanovna-saver depend on the calibration state of the H4 to be correct? 3) Is is possible to store the calibration done in nanovna-saver to one of the memory states in the H4? Storing it in memory #0 would allow for a calibration to be persistent through a power cycle. Thanks and 73, Dean W8ZF
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Question, why when I set a center frequency of 910.525 MHz on my Nano VNA-H4 (as I did here within this image) then I set a marker for 910.525MHz, they are offset from each other?
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H4 calibration
6
Just received my H4. If I calibrate for a range of, say, 144-174 MHz, can I change the range to 144-148 without recalibrating? I guess I'm asking under what circumstances is recalibration necessary?
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* * *How good can a RAIN GUTTER be on HF bands?* * * *Since moving to a "retirement community" last year I have been searching for a reasonably good HF antenna.* *I have tried a few 10-20 ft verticals (not well hidden) and a 140 ft long wire end-fed wire (which everyone can see).* * * *So how about a commercial aluminum (painted) rain gutter.* *I feed it with 50 ft RG8X into a Palomar Engineering 9:1 UNUN with two counterpoises: 15 ft and 30 ft.* *I have a wide-range tuner in the shack, so now SWR issues. * *Well, it is "hidden" and it does tune up on 160m, 40m, 30m, 17m, and 10 meters with SWR < 2.5:1* *but that may mean it is just "lossy" (the UNUN).* * * *I'll give it a try this weekend with Fldigi, running no more than 25 watts on CW, PSK, and Olivia/Thor modes.* *I'm really curious about 160m at night - I have never operated on that band.* *Are there "watering holes" (freq) where different sound card modes hang out?* *Seems like everything is FT8 these days. * *10m should be easy, as it is both vertical and horizontal polarization. * * * *Here are Nano VNA SWR and RETURN LOSS graphs.* *I plot RETURN LOSS as a negative number to have the same shape as the SWR curve. * *I did one run from 1.8 to 8 MHz, and the other run from 8 to 30 MHz. * *I'm excited about this new antenna. No one can "see it".* *But how well will it work? * *de k3eui barry*
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Calibration question
11
I'm new to the NanoVNA H-4. If I calibrate for SWR in the range of 144-174, and then I change the range to, say, 144-148, do I need to re calibrate? IOW, for the purposes of SWR readings, under what circumstances do I need to re calibrate?
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Save change to active trace
5
When I have made a calibration that firstly involves a SWR trace and secondly a trace for Smith, then the Smith-trace is the active trace. Is it possible to afterwards when having changed so that the SWR-trace is the active trace to save that change so when restarting the NanoVNA the SWR-trace is the active trace? Config > Save Config does not help. I realize that making the SWR-trace active before calibration and saving would accomplish that, but afterwards? 73/Torbj?rn/SM6AYM
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I'm new to the group, and also a new user of the H4. I am building a magnetic loop antenna and will be doing a presentation at our ham radio club about the antenna. I would like to show the test results during a live demonstration in the classroom with the antenna attached to the Nano H4 through my laptop. I have not tried to hook up the Nano VNA H4 to my laptop yet. However, I know that it is possible to do so. Is there any drivers that I need to download, or usb ports to configure? I can navigate the VNA pretty well for basic testing without the laptop. I will be connected to the Universities in class computer from my laptop with a HDMI cable to display the Nano's results. I'm hoping to make a stellar presentation so please offer guidance. 73's Mark kd5smf
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Nano VNA H-4 ver 1.2.27
13
Hi Everyone, I'm new to the VNA and trying to measure both inductance and capacitance but getting stupid results. Is there someone who has this version of the VNA could walk me through the setup and menu to do this please. I have checked and checked the various You Tube videos but I am not getting the results I should. I should also mention I am 80 years old. Trying to complete my QMX low pass filters. Failing to get any answers is there someone who would care to correspond by email with me. Very frustrated. Thank you for looking.
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How do I measure this Maxwell choke?
12
I have made a Maxwell choke for my ladder line feed to my doublet. I would like to check the common mode impedance with the nanovna. Do I just use one of the wires for the reading or both? A diagram of it is in the photos section. It looks like this.... /g/nanovna-users/album?id=301856 John K0JHL
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Jog Switch does nothing??
5
I have a NanoVNA (2.8" screen) from about 2020. Overall it works well, but the Jog Switch doesn't do anything. The touch screen works fine, it calibrates OK and measures SWR with ease... but the jog switch doesn't do anything. Should it do anything? Firmware is reasonably current with version 1.2.43 (p: 101 IF: 12k, ADC: 192K, Lcd:320x240) Build time: Feb 19 2025 - 21:39:08 Am I missing anything by just using it via touch screen? An inquiring mind wants to know! -- --- Do Justly Love Mercy. Walk Humbly.
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Hey everyone, True beginner in RF here for a classic alignment question. Sorry if this is inappropriate or the wrong group, I'm not sure where to ask such question. I suppose the NanoVNA would be a great tool to solve the question and you guys seem to know a thing or two about RF. I'm working on FM alignment for Citro?ns car radios from the late 80s and early 90s. For this I would suppose matching the alignment to the OE antenna and cable are ideal for best tuner performance and sensitivity. Therefor I also suppose it would mean making something such as a dummy antenna/aerial or a network so that the RF generator looks exactly like the antenna does to the radio, right? I have the cable, base and antenna of the car taken out. I also have access to a bunch of cars if averaging is necessary. My particular generator is 50ohm. I have no clue what the OE antenna and cable impedance are, as nothing is printed on them. Reading online it seems most automotive radio cable are 93 or 100ohms? For the extra information: there are two models I would like to align, a Blaupunkt which would have a 150ohm impedance, but the other which is a Clarion does not give any information regarding its impedance... it just says to plug the generator into the radio and voila. Thanks for looking into my question.
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Hi DiSlord Coax Zc measurement function, already installed on H4 1.2.40 firmware, seems need to measure C0 capacitance @ 100Khz and the f0 first coax resonance frequency (Hz) and then we calculate Zc = 1/(4 x f0 x c0) Ohm , I appreciate it a lot. Can we do some accuracy correction ? indeed diélectric permittivity of polyethylene diélectric can vary with fréquency , it can decrease slowly up to -4.5% from 100Khz to 14.1Mhz for example , so we can correct C0 value by -4.5% and then ZC should be increased by +4.5% to be more accurate @ 14 Mhz Zc measurement . if our coax has 22.28 metre long with Vp around 83% , the first resonnance frequency will be around 2.71 Mhz wich still far from 14Mhz and may be some % error may be done , I prefer to measure the resonnance or antiresonance the nearest to the 14Mhz and devide by number for correction to have the more accurate Zc value based on measurement done as near as possible to the desired frequency .. What you think about all this view , or DiSlord has already taken in consideration all this possible corrections . 73's Nizar .
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Hello everyone, I have bought a NANO VNA H4 to build simple dipole antennas. Now I have made a simple dipole antenna for testing. This should be tuned for 172 MHz. The total length is ~83 cm (2,72 feet), one leg is ~41.5 cm (1,36 feet). When I now connect this antenna and try to measure it, the result is a lowest SWR (1.15) at 513 MHz. Can this be possible? I am not a radio specialist. I am an IT guy. I have flashed the NANO VNA H4 to the latest firmware (tried DiSlord and Hugen) and also calibrated it. Perhaps I need to make further settings after flashing?
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NanoVNA H FW 1.0.53 Display Intermittent
5
Have an old NanoVNA H with the above FW whose display is intermittent. More specifically, the menu turns off and on or will revert to the main menu. I have tried to do the touch cal and touch test with no success. Appreciate any remarks on the subject; resetting the unit, etc. Thanks in advance. -- William, k6whp -------------------- "Cheer up, things could get worse. So I cheered up and things got worse."
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I ran into a research paper on measuring capacitors using a VNA that might be of interest. It analyzes capacitance and ESR accuracy for the S11 reflection, S21 series-through, and S21 shunt-through measurement methods. The paper covers connector parasitics and fixture deembedding. Lots of useful graphs. https://doisrpska.nub.rs/index.php/electronics/article/view/1330/1237 Brian
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Jittery , non steady readings
8
Is it normal for the readings to fluctuate as much as 2-3 ohms ? As in 11+/-1.5 - j(70+/-1.5) Dipole NMHA (antenna), balun, calibrated, two ferrites: one at the balun and one at the VNA S11 port. No body / coax inadvertent movements, everything taped down near the antenna. Thanks
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I buyed a nanovna H 3.6. When I try to calibrate it, after the full procedure, if I set a Smith diagram and I connect THRU the two ports using the supplied cable the value is 50 ohm instead of 0. I resetted and repeated the calibration a lot of time but with the same result. Can you help me? Thanks
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Sat 8:39am
Sat 8:39am