My HF SOTA Antenna

The Link Dipole and the End Fed Half Wave make up the main choices for HF SOTA activators in VK.
I selected the EFHW design as I felt it would be more flexible to setup as I would not need to support the centre feed point. It also should provide a good match on harmonically related bands and with a compact tuner like the Hendricks SOTA Tuner it seemed the way to go.

sota_tuner

SOTA EFHW Tuner, Mt Hotham

I used this configuration on a few activations happy with the performance on 40m but often could not get a good match on 20m, I also added a “link” to allow me to shorten it to a half wave length on 30m.

At about this point I obtained a nice light weight wire so I decide to re-visit the antenna length and its performance on 20m. So with some research I felt the ‘L’ match was worth a try. This would allow me to change bands without switch links in and out, and I hoped, would also provide a better match on 20m than I had been achieving currently with the full wave length wire.

So it’s still early days with the L match tuner and my plan is to build the L match into the Altiods tin to give me a more compact tuner and possible a little more weather proof.

slt_wire

SLT+ and End Fed Antenna

The vast majority of my activations the antenna wire has been supported as an inverted V, using one of my two squid poles, either the 6m heavy duty one from Hannaford’s  or a 5.4m compact / light weight “Chinese special”. On both of these I support the wire about 1m down from the top to move the weight down onto a stronger section of pole.

To support the wire I tie one end of my 10m guy line (3mm rope) using a Rolling Hitch (A) on the squid pole with the bottom of the hitch resting against the next section down of the pole, to date this has not slipped for me.
After a few different activation I have settled with starting configuration which has the wire providing two guys and the 10m length of 3mm rope the third guy for the squid pole. I have a plastic dog clip (B) on the end of the 10m guy length which I use to make a pulley thus allowing me to get things in place and tighten up the antenna wire without placing too much strain on the pole.  I use the 3mm rope as I find it a bit easier to work with than the 2mm stuff.

So a few photos to better explain how I make it all work.

pole_top_2

Pole showing Guy Line in place. (Mt Major)

 

pole_foot

Foot of pole braced against convenient rock

 

far_end

Far end of wire with 6m length of 3mm line for guying.

 

near_end

Near end of wire, Insulator can just be seen against rock, with yellow wire to Tuner

At the tuner end I have joined in a more robust wire (1.5m long) from the insulator this allows me to drop it down to the tuner and the 3m length of 3mm line can then be tied off to a convenient rock, tree or peg.

On one activation I use the squid pole at the far end of the wire, here I use the 6m tail off the end insulator and the 10m guy line to support the squid pole against the weight of the wire.

pole _at_end

Pole as end support. (Mt Lady Franklin)

 

ant_kit

Antenna wire, Guy line and SLT+

 

I use two figure 8 winders made from Core Flute board, thanks to Andrew VK3BQ for this idea.

Whilst not a large sample this is an interesting look at antenna choices; http://www.sotabeams.co.uk/efhw/