...prompted by this and other threads I thought I would try and build a 1090 tuned Yagi just to see if it would work ( I know nothing about antenna design)! A minimal amount of research turned up a piece of Yagi design software (John Drew DL6WU Yagi design). I plugged in the numbers, rooted round the tool shed, and 30 minutes later had a prototype built out of plastic curtain rail and some 4mm aluminium rod, all stuck together with a glue gun. To cut a long story short I hung this out of my loft window, pointing north, at the same height as my baseplane antenna but about 5 m away from it. I was surprised with the results, firstly that the thing worked at all ;-) and secondly with the resulting max range polar diagram (2 hours) - doesn't seen very directional. I compared this with my baseplane polar and thought mmmm I need to do some more research: firstly to understand how the thing worked, and secondly to build a second prototype based on this!
Attached are images of the two polar diagrams and an image of the first prototype.
