This afternoon/evening I had a chance to temporarily wire up the 2m Cheap Yagi and check the SWR. The results were very surprising after all the discussions I'd had resulting from not following the design exactly to plan. That being, I made the following changes/compromises:
– Went with 1/4" elements for all elements (where as the design called for 1/8" for the DE and 3/16" for all others) as that was all I could find at the time;
– Went with mild steel for the elements (rather than something with higher conductivity – aluminium for example) as again that was all I could find; and
– Although the length of the DE was correct, the J part extended a bit past half way (I rushed it a bit and didn't trim it).
So with those compromises/mistakes I was expecting an SWR above 2. But in the end, I had a 1:1 through the lower part of the 2m band with it not increasing until it hit 146MHz. That is very suitable for my intended use (DX work on SSB down at 144.200MHz) so I'm happy with that.
All that is left now is for me to actually solder the connections (they're just taped at the moment – as I thought I'd have to move them) and then cover with some hot glue. However, I do note that it's efficiency will be down on a version made with aluminium elements and so I've now found a supply of 6.3mm aluminium rod which I intend to use for a second attempt soon.
Oh, why checking the SWR I even stumbled upon VK1PL, VK1MA and VK2ZSZ and VK1JA on a local repeater, so had a chance to ensure it was working.
Photos (only from my iPhone) are:
1. Photo of the quick and easy setup – it should have ideally been higher but I think it still scraped in at about 1 wavelength above ground and easily that clear of surrounding objects.
2. Detail of the feed point on the DE (very poor due to low light and the iPhone) mainly showing where I should have trimmed it ideally; and
3. The SWR readings I recorded.
Now if only there was an easy way to measure the gain and pattern.