The finished product - 4 element Yagi antenna for 50 MHz (6 metres)
This post purely serves as a record keeping exercise for me so that I can check back at some point in the future when I need to view the specs for this antenna I recently built. The design came from a Serbian amateur YU7EF who is a master antenna designer. His webpage is at http://www.yu7ef.com/
This was a fun build and I learnt a lot about antenna construction along the way. Best of all the antenna has proven to be a very good performer. It works! Believe me, I don't get to say that very often when I build something. Mostly it's "oh well, it was worth a try". I have made contacts all over Australia, NZ and into Indonesia so far with the this antenna over the summer Sporadic E season.
I was extremely careful in measuring the element spacing and lengths and was rewarded with a perfectly matched antenna. Here are the vital dimensions and gain measurements.
I used the 10mm diameter elements in my construction so the antenna is extremely lightweight.
Using the ARRL antenna handbook recipe I also constructed a common-mode choke tuned for 50 MHz and using LMR-400 coaxial cable. Here's a photo of the choke.
And here is a pic of the element mounting. Note the ancient Inca rug.
I used Stauff hydraulic hose clamps from the local EnZed outlet. These are perfect for this purpose and cost less than $30 for a bag of 25 clamps.
I am very pleased with this build, the only thing I would change next time is use heavier grade aluminium for the boom. I wasn't able to purchase a heavier grade locally at the time.
Until next time, peace and love.
