[TowerTalk] 5Band antennas

[i4jmy@iol.it]

One of the few 5/6 bands directional antenna that really work is the 
LPDA.
Trapped or shortened yagis have instead the typical problems of losses 
(again, losses are not only in heating and confined the in the traps or 
coils)and more bands lead to have more losses nearly everywhere.
Yagis with half wave resonant elements do not work when the elements 
frequency is close to each other (i.e. a 24.9 Mhz director and 28 Mhz 
reflector) and when too much aluminium is in close proximity.
Concentrical loops, if resonant, suffer like the yagi plus some extra 
harmonically related troubles (not only on odd multiples) and because 
of coupling (link effect)
Like in many other life fields one person can decide what to buy or 
built, it can be an object or a dream. Choosing for the object we pay 
and bring home something real, choosing the dream we pay to believe it.

73,
Mauri I4JMY 






--
FAQ on WWW:               http://www.contesting.com/FAQ/towertalk
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com