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If I may be so bold as to suggest...
Use an RF connector (like BNC, or if you REALLY want to hide it, SMA) bolted
to the turtledeck ground plane or affixed to a plate welded to the steel
tube fuselage. Run the coax from the bottom of the connector to the radio.
On the topside, either (as you have suggested) a rubber duckie that can be
removed for "showtime", or even better, a quarter wave brass brazing rod
soldered into a mating RF connector. The VSWR bandwidth of the brazing rod
antenna is a function of the diameter of the rod; standard 0.125" rod will
give a 3:1 bandwidth of around 5 MHz.; thicker is better but more draggy.
Now it ceases to be an RF problem but a mechanical problem.
If you use the turtledeck, remember that the brazing rod will have a natural
frequency of vibration and if it gets to swinging merrily in the breeze will
fracture at the base of the connector. Doubler plates are the order of the
day.
Jim
<oldsfolks@aol.com> wrote in message
news:1140574954.194166.130870@g47g2000cwa.googlegroups.com...
>I use a rubber ducky aviation handheld antenna on the belly of our
> RV-4 with good results. Maybe that would be less harmful to his
> sensitivities than a quarter wave whip ??
>
> Bob Olds
> RV-4 , N1191X
> Charleston,Arkansas
>
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Re: VHF Com. Ant. for Biplane
