Winding toroids for end fed antenna

[Captain Kilowatt]

Ok. I have borrowed the analyser, and will be seeing the owner tomorrow night.

The only thing that I can think of that might be questionable, is: The far end of the wire is terminated by a porcelain insulator. The near end comes through the top of a window and is trapped by it, leaving a mtr or so, inside the room where I connect it to the analyser.

Cheers, Camerart.

The end insulator should not affect it all and as for bringing it in thru the window that should make almost no difference at all. Been there before myself as well when i brought the end of my random wire straight into the shack and connected it directly to the tuner. I only did that once however. FAR too much RF in the shack. My microphone kept biting me.

 

[W5LZ]

... your microphone just didn't like you.

 

[Captain Kilowatt]

... your microphone just didn't like you.

Maybe my mouthwash just wasn't cutting it.

 

[camerart]

At this point I have to say that either something is not as it is being presented or that there is a problem with the analyzer. There is no way 20.1m of wire should show resonance at 5.79 MHz ESPECIALLY after shortening it a further 10 feet. That would make it about 56 feet long which should be a half wavelength at about 8.4 MHz. I suggest you either consult someone local that is knowledge in antenna systems or even post pictures of what you are dealing with because something is just not right.

Just checking.

Did you notice that I connected the wire straight into the analyser, with no earth connection?

Camerart

 

[W5LZ]

Do you, by chance have a section of that 20.1 meter wire wrapped in a coil?
- 'Doc

 

[camerart]

Do you, by chance have a section of that 20.1 meter wire wrapped in a coil?
- 'Doc

No. I'm trying to be a scientific as possible.

Analyser on bedroom window ledge, wire (20.1+a little) up and over the top of the window, straight down to a porcelain insulator, then tied to the garden fence.

I have just tried it with an earth to the analyser, different results but same effect.

Cheers, Camerart.

 

[Captain Kilowatt]

Just checking.

Did you notice that I connected the wire straight into the analyser, with no earth connection?

Camerart

Yes I noticed that. What you are seeing as a resonant frequency versus whet the length of the wire is just does not make sense under any circumstances except possibly for this:


"...up and over the top of the window, straight down to a porcelain insulator, then tied to the garden fence."

Does this run truly straight down against a building or a long gentle slope to the ground? Straight against a building would detune it drastically whereas a long slope should not. Other than that I am lost. I have installed several wire antennas in the past including several end fed wires about 20m long that were used as half slopers on 80m and they all worked well and were very close to resonance at the theoretical length.

 

[camerart]

The wire runs down a slope, between 2x buildings, and not far from plants.

I have just lifted the far end, by fitting a temporary plastic tube to the fence, so now it's about 3.5 mtrs.

I was advised to use the 1.4 wave reading for stability, then double it. I tried with the different set-up, exactly the same result.

This wire was fitted to a successful toroid before, so I think I'll just put it back as it was till I get a clear answer.

Cheers, Camerart.

 

[camerart]

Hi all,

I've just had a message from the analyser owner, who tell me that after some research, the analyser will not give long wire impedance higher that approx 500 Ohm, so that answers some of the posts.

Cheers, Camerart.

 

[camerart]

Hi all,

I've just had a message from the analyser owner, who tell me that after some research, the analyser will not give long wire impedance higher that approx 500 Ohm, so that answers some of the conflicting posts.

Cheers, Camerart.