[TowerTalk] yagi top loading of tower

[Al Williams]

I have two questions about using a 70' crankup with a yagi as a vertical
radiator for 80m & 160m.

1.  Will Force type yagis (insulated from boom) provide top loading;
could the insulated yagi actually be detrimental?

2.  Would extending the mast above the yagi be beneficial?  I am
thinking of some successfully smaller diameter aluminum tubing
      installed at the top of the mast perhaps 20 or 30'.  Nothing
attached to the extension or perhaps a small umbrella type hat.

k7puc