This is the final model. I looked at many different ideas on the internet. I wanted it completely portable. The feed point I decided to use some 8mm tube section and the elements are 6.35mm solid bar. I used a rap & die set so that I could unscrew the both sides of the feed point. The elements are secured onto a 25mm conduit with some conduit clips which I managed to find that would allow me to drill a hole for the elements. These can then be taken off the rod and then the elements can be stored in the boom.
I am going to cut the boom down and use a conduit coupler to attach both parts back together.
I used a conduit T piece for the boom to mast fixing which I used a hole cutter to open the inner part up so that I could push the boom all the way through. This is a tight fit but allows me to turn the yagi from horizontal to vertical.
I used my Rigexpert AA 230 zoom for fine tuning, I am no expert but found the resonant frequency changed slightly from horizontal to vertical but as the conduit clips move I managed to find the best resonance for vertical as seen on the next two pictures.
Nice antenna, and I can guess where you got the ideas from.
I’ve had a similar design on the drawing board for a while, but other projects have priority.
Where did you get the conduit clips? I couldn’t find a UK source for that style.
The clips are ordered on line but picked up from my local City Plumbing centre. As you can see from the link 20p + vat each so not too bad. They don’t stock them as I found out by visiting and was asked to order them online.
Have fun building it, the feed point took me the longest time.
I think you’ll find the antenna very useful on a summit. I wouldn’t be without my SB5 (SOTAbeams, based on the design by Martin DK7ZB)… except when I forget to pack it (with apologies to Don G0RQL).
I find that the biggest problem with a beam on a summit is that the wind will try to control the direction that it faces, and trying to maintain a beam heading is distracting while operating and logging. Do you have a solution for this?
Attach a length of guy line to the front of the beam and peg it out in the required direction. More useful for activating places like Scotland where 90% of the contacts will probably be to the south.
