开云体育

If one measures SWR in the shack considering the antenna plus feedline (assumed coax) as a system, there is a good way to verify there is no standing waves or reflections on the line - A totally

“If your "generator is Z1=R+jX, for VSWR to be 1:1 the load must be Z2=R+jX (R=R and X=X, if not obvious otherwise)” Correction - the load impedance must be the complex conjugate of the source

A simple answer - for VSWR 1:1, X must be 0 and R must be 50. In any other case you will have "impedance mismatch", that will causes "reflection", and reflection "causes" VSWR A bit longer

Yes the lengths are wrong but the DX Engineering one is even more off John ve3ips So 34 ft for 40 and 70 for 80m then tune for resonance John ve3ips

Well, can anyone come up with a case where the VSWR measures at 1:1 and the Smith chart is not on the zero reactance line. And in fact for 1:1 you would have to be dead center, based on analysis

Hello David, The 40M leg is too long. The SWR and RL are rising with the increase in frequency. The 80M leg is too short. The SWR and RL are improving with the increase in frequency. HTH...Bob VK2ZRE

William, As mentioned our local radio club has a copy, but I'm not there for a few weeks. Stan Dye already answered my question, but will still read the book when I'm next at the club. I've the Radio

Maybe, I have more than one complaint, the screen seems insensitive especially when I'm trying to program frequency, those numbers just don't want to respond. Other times the sensitivity is fine

Your unit might not be broken, in the conventional sense! Read in this group about adjusting the display. The display on the nanoVNA is resistive, and many times issues can be corrected by adjusting

Hey, I wired up a 118' X 68' crossed dipole antenna per the recipe here https://w8jxn.org/?p=1650. I was able to get very good transmission 5x9 to a collaborator some miles away on 3.915MHz. The 40M

I borrowed a friends NanoVNA, same model, same reputable seller. The borrowed unit works like my unit never worked. It was always a bit difficult to get the screen to respond. I wish I had known how

Any of the NANOVNAs are well suited to make your desired measurements: SWR and R ± j X. Minimum or 1:1 SWR is not a good indicator of resonance, regardless of ham "lore" and misinformation. The

Peter: It really, really is a fantastic book--- The KINDLE digital download version has links, diagrams and explanatory text--- DO THIS: 1. Estimate the price of your ham shack's current equipment.

Just remember that if you want to know where the antenna is resonant (reactance = 0) you have to measure at the feedpoint of the antenna NOT at the end of the transmission line in your hamshack. It is

Thanks Steve!

Thanks Bill, Maybe someone can explain it in a message? I think our radio club may have a copy, but I'm not visiting for a few weeks. Thanks

Look at the display options to show R and X traces. But the easiest way to see resonance is on the default smith chart- wherever the trace crosses the horizontal axis is a resonance point. You can

Peter: Yes. Buy a copy of "NanoVNA EXPLAINED" by Mike Richards, G4WNC. It's a RSGB book. Get it on Amazon. I have the Kindle version downloaded immediately after buying it. Very thorough and easy to

Thanks Bill, Sorry, my image didn't appear as I had planned. So can resistance and reactance be displayed at the same time (I assume multiple traces?). Can anyone direct to a tutorial? Thanks Peter

Yes NanoVNA can measure resistance and reactance as well as a Smith chart. Resonance is the frequency at which the antenna is purely resistive, and no reactance. You seem to be already aware that the