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Francisco, The ttrftech reop only contains H and earlier firmware so you have no issue with installing anything from there on to your Nanovna. Hugen makes versions for H and H4 but they all have H or

I have a spreadsheet that I use...developed after much research into the subject of sag and tension... I set it up for a nominal Synthetic Textiles support rope - 5mm and antenna for a support span

Apologies if I'm wrong but nobody seems to have asked if there is a balun at the dipole feed point. If there is no balun the coax will be part of the antenna, which would explain lower frequency

I try several firmware at https://github.com/ttrftech/NanoVNA/releases but issue remains. Also I cant tell if those are for H or H4. In other place I found one still old (0.4.5-4 ) with a clear

Whether the system of transmission line plus antenna is resonant is a matter of how you define terms. Me, I'd say a specific length of transmission line is as acceptable as a lumped LC impedance

If the nano follows the HP network analyzers, it doesn't matter what the order is until after DONE is pushed.....even if you did one of the conditions over again. Does it matter with the nano?

Ed, He is not seeing more "antenna resonances". The antenna is only resonant at 9 Mhz., 27 MHz. 45 Mhz. etc... What he is seeing is the reactance at the input of the coaxial cable become 0 at

River, I think you may want: https://github.com/ttrftech/NanoVNA/releases/tag/0.8.0 0.8.0 allows Stop Freq up to 2.7GHz. On my unit, (NanoVNA-H V3.4) it is only useful up to 2GHz or so. Up to

Ahh, antenna voltage is exactly equal to Vsum. I wrote: "Which I did not expect, let me know if I have it wrong," I was not wrong, just a little bit thick headed. Those are both real voltages

Ed, Looks to me like he really does have all those resonances at the transmitter end of his feed line. An appropriate length of feedline will turn any arbitrary impedance into a pure resistance. See

This is a correction to my first post. Unfortunately that simulation was not done in high accuracy mode so it did not correctly model the effect of ground so close to the antenna. The following

I was inspired by Jim's quick work plotting the Bessel functions, decided it was time to figure out python's matplotlib. The result is this animated GIF:

Ok. We all agree free space theoretical resonance would be something like 9.35 MHz. We also agree closer to ground would lower fundamental resonance to something lower, like 9.125 or so. But I have

Hey John, Version: 0.4.5-4-g96e7efe Build Time: Jan 18 2020 - 23:46:29

and one might want to disconnect "resonance" from "radiation efficiency" - a 10 meter long dipole (resonant at around 15 MHz) will efficiently *radiate* over a huge range of frequencies, probably

River, If you select Config/Version, what Version and Build Time is displayed? --John Gord

I recently bought the NanoVNA-H ver 3.4 and I have upgraded the firmware to the following release (https://github.com/hugen79/NanoVNA-H/releases/tag/0.4.5-4) to allow it to measure beyond 900 MHz.

Thank You very much. I am sorry that I did not mention the feeder cable originally, and I did not clarify that the antenna was not the main object but the combination of the antenna and the feeder and

Im now waiting on an eBay dealer to swap out a DOA vna-f that also had a unresponsive menu. I didnt attach it to anything and it's menu was real flakey (hit and miss). It's best to avoid the rabit

You have the impedance looking into the feedline from the transmitter end, but now you are asking what the antenna is doing. An arbitrary amount of feedline will rotate a point on the smith chart