[Antennaware] studying legacy KLM 20m big stick with eznec5

dan edwards w5xz at att.net
Mon Mar 16 10:10:59 PDT 2009


guys:

i found the factory dimensions of the old 58' boom 6 element KLM 20 at W5WMU.
he still has two; or at least most of the pieces of two of them.

I modeled the parasitic elements with eznec 5, including the taper correction with
actual element diameters and specified lengths, and replaced the dual driven elements
with a single driven element.

this thing has a deserved reputation for being a 'HOSE'...looks very nice. 
to me, anyway. decent gain for boom length, and fairly clean pattern, across
the whole band.

curiously, though, by tweaking the single driven element length, i get a pretty nice
swr / freq bandwidth with it fed DIRECTLY with 50 ohms. was thinking of 
applying the 'owa' approach with an additional director, closely spaced to
the driven element, but it does not seem necessary.

Is this an artifact or error? i'm modelling it at 70' over 'real-hi accuracy' ground.

Are these dimension proprietary or copywrite or patent protected?

we are slowly repairing hurricane damage at W5WMU, but this time, using 
EZNEC to re-deploy the useable aluminum. hopefully the best way.

73 from texas, W5XZ, dan


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