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What is a good NanoVNA to buy for do antenna reading like SWR, VF and Length of coax cable type work. Also, location of short in the coax..

Tried to update my H4 with the app and got this error: Opening \\?\usb#vid_0483&pid_df11#206a31562031#{a5dcbf10-6530-11d2-901f-00c04fb951ed} open failed Device Manager shows NanoVNA-H4 is connected. What to do? Mark Jordan, PY3SS

I have a NanoVNA-H4 which has been working for months. Today I needed to test a broadcast band filter and when I try to enter any number on the number screen (for setting stimulus start/end etc.) the screen goes fully white. All other functions of the NanoVNA seem to be working fine, only the touchscreen is bad. I've re-done the touchscreen calibration (which works normally), saved it, and done the touchscreen test which doesn't indicate any problem -- I can drag the guitar pick up, down, right, left, and diagonally in any part of the screen and it looks fine. I see in searching for this problem many people have had touchscreen issues, but none just like this. I will try flashing a different version of the firmware (this is Dislord's 1.2.40) and following that if needed I'll disassemble the case to inspect the ribbon cable. Any other suggestions?

Does anyone want a copy of the January/February 2025 issue of QEX? The ARRL sent me two copies. It has the tinySA tracking generator design article in it. Of so *respond to me privately* at kc0wjn at gmail dot com Responses to the list will be ignored. The magazine is free; shipping cost from 32754 USA to be paid to me by PayPal F&F (the shipping cost using USPS Media Mail is probably trivial). DaveD KC0WJN

Hello, has anyone measured or knows what is the maximum length that nanovnatdr can measure NanovnaH4

Hi all, is there a method to set a marker to a specific frequency, by numerically entering the frequency? I searched through the menus and manual but could not find anything. When operating with desktop VNAs I often set markers to specific frequencies, e.g. 2.4GHz, 2.45GHz, 2.485GHz to check the VSWR of an 2.4GHz antenna at the lower and upper bound and the center of the band, to quickly characterize the antenna over the whole band. By punching in the frequencies, the markers are quickly set. Using the rocker switch to set the markers on the NanoVNA takes a lot longer. If this is currently not possible, this may be a useful future feature if others find it helpful too. Thanks!

The timeline for submission of papers and presentations has been extended to March 17th.

When using my NanoVNA to adjust length of a 20m hamstick, the readings kept changing depending on what the NanoVNA was sitting on (truck hood, pelican case, my thigh, or in my hand). How do I get a reliable reading that I can count on for a properly adjusted antenna? Thanks, Coyote

My NanoVNA H4 is not operating properly, I'm about to buy a new one. Is R&L the place to get a real model? Mikek

With the ADC detection button, you can set multiple shortcut keys, such as entering DFU mode, taking screenshots, pausing scanning, and so on. Because of these menus, I need to click several times to find the location, which is very inconvenient for me, so I thought of setting this shortcut key to enter the corresponding menu with one click. I guess this should be a very useful feature.

My first VNA SAA-2N in 2020, love the large SO-259 connectors instead of SMA connectors. I notice that my touch screen is not working right. Hit display nothing happens, trace doesn't do anything either. Can this be corrected. I purchased a new NanoVNA F V2 that was 3x what I paid for the SAA-2N. I don't like the menu layout or the SMA connectors. The 2 RF cables are so stiff they hardly bend, afraid using them I will break the SMA connector on the Nano. What is the difference between the F model and the H model. Cause I may return this F with these 2 stiff RF cables

Sad news: https://www.owenduffy.net/ (mostly electronics) is no longer available. regards Fred

Yeah, but there is the problem that the resistances are small (compared to impedance), so things which have “percentage uncertainty” (which the VNA uses) will be tough. It might help to look at the uncertainty of your measurement (that is, how the calculation of impedance is done). It may be that your measurements are within the uncertainty of each other. Z = Zo * ((1 + Γ) / (1 - Γ)) Gamma, here, is basically the ratio between the forward and reflected voltages. Which are complex numbers, where the uncertainties are roughly equal in I and Q.

I built this fixture some time ago. It makes measuring chokes, baluns and ununs common mode very simple. The SOL(T) CAL loads are built onto the PCB. My interest in common mode reduction now lies in VHF and UHF where this jig will not function because of lead lengths. All mounting hardware (except the banana sockets) has been replaced with stainless steel. https://electronics.halibut.com/product/common-mode-current-choke-test-rig/ $50 includes USPS shipping in the USA. Regards, Dale W4OP

I report with a heavy heart, confirming your suspicions. The hobby has lost one of its greatest on-line resources. Read on. Ed McCann AG6CX