Alan, absolutely a great post, and well said. You are right on the money!
Effective power is the key. An improved or efficient antenna is the lowest
cost route to effective radiated power.
A point was made in the QRP forum at the local ham convention Sat. Even if
you are using one of the shortened antennas, you still have to keep the high
voltage ends well away from conductors and screening foliage, or other
detriments to the high near field levels.
And the high current magnetic field concentration near the feed point should
also be protected from coupling to conductors.
A dipole can be shortened to 60 per cent of full length and maintain
efficiency in the greater than 90 per cent
value. You just have to have it in the clear of detractors from its field.
Low profile antennas like the Moxon rectangles can provide beam performance
in less than traditional Yagi dimensions. Use of low loss insulators,
conductors, and fasteners is key to small antenna use.
An easily elevated small beam may be the answer for aging hams. The masts
from Force 12 that were marketed for portable use come to mind. Motorizing
such an elevating cable for that mast might be fairly simple.
-Stuart
K5KVH
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