How do you put capacitors in? Is this a good slow wave solution?
CCD antenna use capacitors in a distributed way to cancel the inductance. They
are commonly used in 1 wave dipole configurations. They have higher feedpoint
impedances than 1/2 wave dipoles and they have 3 dB gain when fully stretched.
Their pattern is figure 8, like a 1/2 wave dipole.
The Vincent antenna could use such an arrangement to emulate a 1/2 wave
monopole CCD (that is, a 1 wave dipole) where the 1/2 wave electrical length is
wound into a helix along the height.. In any case, there are a number of ways
of doing this. In my opinion, this is not new, if that is the case.
I suspect that Vincent has a number of combinations of arrangements, depending
on the desired height above 1/30 waves.
Remember: these are not efficient antennas; they are slow wave antennas. Put
lots of power into them and they will heat up; arc; and melt. They trade gain
against efficiency. They are not multi or wideband.
I would be very interested to know how hot a Vincent antennas when running 1500
watts continuous for an hour....If it's hot it's not efficient.
73,
Chip N1IR.
|