Thanks Terry for the info. Feeding at top of center element looks
electrically attractive, but less so mechanically. Thinking about this leads
me to wonder about running the coax up through the inside of the center
element which is guyed 2" al tubing. The coax would need good
insulation(polystyrene tubing?) at the exit point, but could drop straight
down and go underground to the phasing network with addition of 1/2 wave of
coax. (total 3/4 wave). Currently using 1/2" lexan lag bolted to 4x4 set in
concrete and tubing is clamped to the lexan. Boy that stuff is bullet proof
and does not tend to misbehave when you saw or drill it.
Do you know if this has been tried or if there are any snakes in the grass
that I am missing? The model suggests that the 1/4 wave feeds would be
better with 75 ohm coax.
Comments appreciated
Sam W5LU
>
>Probably the easiest way to feed phased bobtails is to drive at the
>low impedance points at the top of the center wire. Then you can use
>normal amateur practices for phasing networks.
>
>I have attached 3 EZNEC models for Sam: Single Bobtail, 2 Bobtails
>with Voltage Feed, 2 with Current Feed.
>If anyone else is interested, I can send them a copy, too - reply off list.
>
>73, Terry N6RY
>
>
>
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