[TowerTalk] DX Engineering 20DX-5 modeling

[W0YG Charlie Summers]

Has anyone modeled the old DX Engineering 20DX-5 antenna?  This was a 5
element 20M yagi on a 43.75 foot boom.  The reason I asked is I just spent a
whole morning trying to tune one by yanking it in the air after every
adjustment and it just never came into what I considered acceptable
parameters.  So, I modeled it in EZNEC and find that it has some problems
the way it is factory set.  For one thing, the forward gain and f/b are not
what I would expect.  For another, there is a strong lobe straight up, a
cloud buster.  For another it is hard to move the frequency down.

Let me explain.  If you set it the way DX Engineering said, then it
resonates at 14.280.  By playing with the driven element, the first director
and the reflector, one can get it to move down to about 14.200 where it
plays but still I am not quite satisfied.

I asked in the first paragraph above if anyone has ever modeled this
antenna.  Perhaps I should have stated has anyone ever run YO or some other
yagi optimizing program on it.  That is what I would like to see the results
of.

73,

Charlie, W0YG..>>