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Old August 23rd 04, 04:20 AM
Yuri Blanarovich
 
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I was under the impression that radiation efficency was pretty much a"
no-brainer".If the antenna is built of quality materials with good
workmanship the antenna would be an efficent radiator with little ohmic or
dielectric losses. The exception to this of course would be antennas that
use an earth ground. I just found I was losing at least 3 db to heating up
the ground.

Jimmie




Keep digging, you will find more lost dBs. Things get aggravated in loaded
antennas when you start inserting coils, loading elements, folding them back,
etc. Efficiency is roughly proportional to the area under the current
distribution curve along the radiator. That can be affected by any of the
shortening "miraculous" gizmos, like Vincent DLM antenna. It is not just heat
loses in resistances. You can't have "perfectly" conducting piece of 1 ft
copper tubing be as effcient as 130 ft full size radiator on 160m.
Getting smarter, Eh ? :-)

Yuri, K3BU