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Be careful when measuring wire antennas with a NanoVNA because static build-up can damage the input. -- Mike

Hi Fran?ois, I have attached the EZNEC model. Remove the .txt suffix before running. -- Mike

Not exactly. You can feed any length of wire and it will radiate. A very short wire will have a very high impedance, so you’ll need a lot of voltage to get some current to flow. And the current

I am not speaking of the method of feeding, only of the characteristics of a wire antenna itself. Antenna engineering was one of my minors as an electrical engineering student. The other one was

I think your assumption is wrong. When we feed an antenna, made of a stretched wire, from one end, in fact we build an antenna which looks like a dipole whose feed is off-center. The second strand is

A half-wave antenna has the maximum current flow in the center and 0 current flow at the ends. Ideally, it would be fed in the center. Current flow is what produces an electromagnetic field, and at

These are often referred to as "end-fed RANDOM WIRE" to distinguish them from the "end-fed HALF-WAVE" type. The end-fed random wire user needs to avoid resonant wire lengths, the half-wave type

** Yes, also Modeling an End Fed antenna in Eznec requires precisely defining the geometry of the counterweight which, in certain cases, is constituted by the outer sheath of the coaxial. -- F1AMM

Hello Mike, I am interested in that EZNEC Simulation. 73 Peter -----Original-Nachricht----- Betreff: Re: [nanovna-users] where is the end fed natural resonance Datum: 2024-02-26T09:10:04+0100 Von:

I understand that, but a PCB is (of course) not just for professional) looks. You see on all RF circuits the GND-stitching all over the place :-) But of course, if you experiment or build prototypes

I suppose you are right. By the way if you search on "RF Demonstration Kit NanoVNA VNA RF Test Board Filter Attenuator PCB RF Test Board Vector Network Analyzer Learning Tool Kit" you can find a test

Sorry Barry and Dave, I read your posts while half asleep and now realise you are talking about an end fed, not an end fed half wave! Anyway, I thought I'd include details of my own measurements to

It should be noted that an antenna can be an "end fed" without being an "end fed half wave." Antennas that are not half wave but are, in fact, end fed, are often used with a 9:1 balun. 73, Jim KX0U

If you are using a 9:1 unun then it's not an end fed. My EFW4010 gets me around the world on 100W SSB. My measured SWR is the same as simulated by EZNEC. If you're interested I can send you details

Thanks for posting, Barry! So you are discovering there really is no "end fed" resonant antenna. The proof is in the measurements as you show. So why is this abortion so popular??? ONLY, and ONLY

Looking at the photo on their website, the switching is easy. They use a 2-turn primary and 16-turn secondary winding on the toroid. The switch would simply take the antenna output from taps on turns

I'd try swapping various USB-C <> USB-A cables before cutting up a cable. From past experience I've found some cables are not made with copper wire that you can solder to but aluminum wire or

Hi Don, I wonder how they switch that. it looks like an ordinary ferrite core coax wound 1:1 balun.. I like the concept though . Bryan, n0luf

I have a 40m wire on a 9:1 which it mostly flat, strung between 2 30 poles, is sags a little in the middle. I had a counter poise on and it was just okay. I removed it and now have just a choke at