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The EASIEST Antenna to build for Six Meters using one piece of RG-58 coax!

4 December, 2020 - Reading time: ~1 minute

This is a really simple and easy to construct antenna that will get you on the air on the six meter band using only RG-58 coax!

I needed a quick and simple antenna for my WSPR beacon over the summer season. Enter the end fed half wave length coaxial dipole or aka flowerpot antenna!

The design details are available at VK2ZOI's website below:

https://vk2zoi.com/articles/half-wave-flower-pot/


Explaining End Fed Half Wave Antennas & Experimentation

23 October, 2020 - Reading time: 4 minutes

This presentation explaining the basics of End Fed Half Wave (EFHW) antennas was done at the DATV experimenters night hosted by Justin VK7TW and Hayden VK7HH. Topics covered were the basics of EFHW antennas by Steve Yates AA5TB including lengths, design and installation of the antenna. Voltage and current distribution and the issues this presents, the minimum counterpoise, impedances and turns ratios of end fed impedance transformers.

Hayden VK7HH then took the audience through a great presentation on his experiments with his EFHW. Hayden covered the modification based on the VK4YE design, the testing, and the additional 80m loading coil, the coax counterpoise, and the common mode toroids. This allows a antenna for smaller spaces.

References:

Steve Yates – AA5TB http://www.aa5tb.com/efha.html

http://www.aa5tb.com/efha_wrk.html

http://www.aa5tb.com/coupler.html

Ben - VK7BEN

https://www.vk7ben.id.au/2017/01/09/experiments-with-an-end-fed-half-wave-antenna/

VK4YE

http://sarc.org.au/wp-content/uploads/2015/07/VK4YE-End-Fed-Antenna-Construction-Project.pdf

Steve Dick - K1RF (The End Fed Half Wave Antenna)

http://gnarc.org/wp-content/uploads/The-End-Fed-Half-Wave-Antenna.pdf


My New HF End Fed Antenna

6 October, 2020 - Reading time: ~1 minute

A quick #shorts video on my new end fed half wave antenna. As you can see it seems to be a good start, but requires a bit more tuning.

A more in depth video coming soon.


An 8 element LFA on 2 metres

24 December, 2018 - Reading time: 3 minutes

With the success of my 11 element 2m LFA, I decided to build a smaller 8 element out of spare material I had here at home whilst waiting for the propagation to pickup (note I'm still waiting on you E-Layer!).

The idea behind it was to build a yagi for either portable use, or to replace the 7 element YU7EF at the remote station to see how it performs. I chose the 8 element model detailed on G0SKC's website.

Justin had the details for using 6mm and 13mm tubing, however I only had 6.35mm and 10mm on hand, so I popped the figures into MMANA and rescaled for my material.

The antenna pattern looked good, note the near 30dB F/B ratio and reduced sidelobes. Comparing this to the 7 element I have at the remote station showed a significant improvement. Red is the LFA, Blue is the YU7EF on the remote station.

Anyway... enough theory. I managed to build this up in an afternoon. I took my time measuring and cutting the elements. Some photos.

Another good build requiring little to no adjustment to obtain a decent match. Now to find a place to use it!!


VK7HH LFA Build and performance

22 January, 2018 - Reading time: 6 minutes

Further to my previous posts on the "hybrid" LFA...

 

I managed to finish construction over the weekend and install it on my tower. At the same time I also decided to take down my 6m yagi to convert to an LFA design too. So how does it perform?

That evening I ran some tests with Peter 7PD on WSPR. There seemed to be some tropo enhancement as usually I cannot hear him from my location. Tests seemed to show the antenna was working quite well. I also tuned to a local beacon and noted signal strengths pointing in different directions. In this area we have a lot of mountain ranges so it's difficult to get an accurate reading due to reflections/refraction from the beacon.

The most impressive bit about this antenna though that I noticed straight away was the lower noise I had overall on 2m. You may recall in my previous post  I mentioned that in the ZL direction I had high levels of noise on 2m. Well, this antenna has certainly improved on that! Rough measurements on the old antenna indicated about 12dB of increased noise in Spectrum Lab when pointing at ZL as compared to a relatively quiet area. The noise level increase is now only 6dB over that same direction. In fact the noise now peaks between 30-60 degrees, which is perfect as there is nothing to beam at in that direction.

Below are some photos of the build. As detailed before, I just used three (all I could fit) ferrite cores of known impedance over the feedline and placed them as close to the feedpoint as possible. I then also slipped three further cores, around the bend of the coax underneath the boom. I also made a "ugly balun" of some sorts, 2.5 turns of coax... I also connected the centre of the driven element non-feed end to the boom using a small screw and some lugs.

Photos of build below.

Loop assembly with coax feed.

Close up of mounting method to boom/mast

Boom to centre of driven element. Note, another lug is present under the screw head to the right hand side of the photo, soldered to the centre screw lug.

Return loss come up pretty good.