Topband: high take-off angle

[Dave Mueller]

When designing a low band antenna for my Guam QTH, I purposely went 
through great trouble to make a true "TEE" vertical to avoid having an 
inverted L on 160.  I figured that being limited to 55ft of vertical 
height, the rest of the "L" would present a significant higher angle 
horizontally polarized component.  I am located 1,500 miles from Japan 
and 7,000 miles from both Eastern North America and Western Europe.  I 
wanted to maximize low angle takeoff and efficiency by using top loading 
and a good radial field, and to keep the radiating portion centered as 
much as possible over my radials.

I understand that high angle propagation does occur on 160m, however low 
angle generally rules.  With room for only one transmit antenna, I felt 
it was more important to be prepared for the 90% scenario, instead of 
those rare occasions when high angle takeoff is a factor.  I think those 
who worked me for a new one and those who still need Guam on 160m will 
thank me for the decision I made.  By all means, if you have room for 
more than one antenna, a second high angle radiator could be the trick 
to completing some QSOs.  However, if you only have room for one, I'd 
aim to have a radiator as high in efficiency with as low an angle of 
takeoff as possible.  This is what you get with a vertical over salt 
water, usually considered "the ideal situation".

73, Dave KH2/N2NL