Topband: 3/8 wave antenna

Tom Rauch W8JI@contesting.com
Sun, 19 Dec 1999 10:05:52 -0500


> Roy K6XK wrote: 
> 
> >A 3/8 compared to a 1/4 wave INV L only pushes the current portion up
> >farther into the undesireable horizontal part of the element.
> 
> What you are say Roy is correct only if you let the verticle portion of
> the 3/8 antenna"s vertical height is less than 64ft (1/8th wave). The
> antenna must be at least 64 feet in a vertical direction. 

Roy is correct at any height vertical section.

Moving current out into the flat-top area is undesirable, especially 
with a modest to good ground system. 

If the flat-top was totally non-radiating what you would want (for 
maximum efficiency of the vertical radiator) would be maximum 
current at the exact center of the vertical run, not right at the top.

If the flat-top radiates, you'd want the max current farther down in 
the vertical section.

If the ground system is terrible, all bets are off as to what would be 
best.


73, Tom W8JI
w8ji@contesting.com



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