At 10:31 AM 12/16/1999 -0500, Guy Olinger, K2AV wrote:
>>>The offsets can be compensated for easily with a little longer coaxial
>>>calbe that acts as a delay line to electrically aliegn the driven
>>>elements, when pointed in the same direction.
>>>
>>>Its already been done.
>>
>>
>>On 3 bands with the same length of coax?
>
>Sure, you are compensating for a distance in the open with a piece of
>coax with that has the same velocity factor on the bands in question.
>It does assume that you are not using 1/4 wave matching sections and
>the like, eg using a stackmatch type of matching.
Hmmm.... I hadn't thought about it that way. So the 5-foot driven element
offset (for example), is twice the phase shift (in degrees) on 10 that it
is on 20, and the same length of coax (5 x VF) provides the needed shift.
I suppose you could model that in EZNEC easily enough, and see if it really
works. In fact, I think I'll do that with one of my stacked C-3 models and
see what happens.
73, Pete N4ZR
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