Hello OM's!
I ask your input, ideas and suggestions for feeding and matching a
triband boom as a 40 meter rotary dipole.
Here, my 24 foot TH7DXX boom will be at 61 feet on a tubular, crank up,
tilt over tower. So I do not have the option of tuning a matching
network while atop the tower. For me, modelling is not a viable option
either.
What could be done with the tower cranked down to 29 feet? A temporary
1/2 wave feed line plus a temporary length of ladder line with a variable
capacitor at the bottom to determine gamma capacity?
Preference is a slanted gamma rod of RG-8 sheath with vinyl cover
slanting from a boom attachment about 8 feet from the mast up to a
waterproof box on the mast.
Would there be any advantage dangling 2.3 foot wires from each end of the
boom to bring resonance up to 7mHZ?
I would very much like to hear what techniques others have used together
with gamma rod length and gamma or omega capacitor values.
DX forever!
73,
Allen Robbins W7AM
|