Folks,
I've lost track of who suggested this...but I would like
to hear from anyone who has modelled or actually installed
two log periodic arrays, stacked, but NOT parallel.
That is, by tilting the leading edge downward, on the UPPER
lpda, and the leading edge of the LOWER lpda UPWARD, it should be
possible with an 18' boom lpda to have the first 10m elements
spaced by 16', and the last 20m elements spaced by 32'.
I haven't bothered to finesse the geometry, but it would appear
possible to space and tilt such that you obtain maximum gain
from the stack, when driven in phase.
Anyone actually DONE this? W1CX relates seeing a pair of KLM
7-30 lpda's like this in Panama, while transiting the canal.
For purposes of discussion, assume there will be no mechanical
mounting issues.
Jim Jarvis, N2EA
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