[Antennas] Krazy Antenna Idea

2002年5月01日 16:37:07 -0500

Radials that are in contact with the ground are detuned by the ground and
need not be resonant. They are there to collect return currents within
about 1/4-wavelength of the base of the antenna. Length is not critical -
the more the better.
Radials that are elevated need to be resonant to be effective. That means
that their length is critical as are their surroundings. They cannot lay on
something like a carport roof that would detune them. They cannot be
connected to ground or anything except an insulator at the far end. Snow
will probably detune the radials, perhaps substantially.
A radial that starts out in the air, runs along a roof and then dives down
to be connected to ground is not really a radial but an extended "ground"
wire that is too long to have much effect.
I see little need to elevate the antenna for 160. Put it on the ground and
put out as many radials as you can of whatever lengths you can fit into the
property. More shorter radials are better than fewer longer radials. Snow
will have little effect.
I would forget about the carport . . .
73/72/oo, George W5YR - the Yellow Rose of Texas 
Fairview, TX 30 mi NE of Dallas in Collin county EM13qe 
Amateur Radio W5YR, in the 56th year and it just keeps getting better!
QRP-L 1373 NETXQRP 6 SOC 262 COG 8 FPQRP 404 TEN-X 11771 I-LINK 11735
Icom IC-756PRO #02121 Kachina 505 DSP #91900556 Icom IC-765 #02437
Chris BONDE wrote:
>> I have been planning on being on 160m. The upper portion, say 1850 to 1975.
> I have a carport that runs E-W, that is the length, the mountain to the N
> fairly well prohibits propagation that way.
>> If I mount a vertical on the N side of the carport, run the radials E-W on
> the N edge, S-E and S-W to the diagonal corners, and, S on the width, with
> possibly, the radials from the N wrapping along the edge to join the
> diagonals which could go to the ground and be grounded, along with the
> width N-S going to ground over the edge. This is the first question how
> would that work for the radial system? How would the snow on the roof of
> the car port, up to 4ft deep, dry and wet, influence the radials plus the
> antenna. Now that is something else.
>> __________________O________________________
> ! / |
> \ |
> | / | \
> |
> etc
> Any comments on this radial system?
>> Chris opr VE7HCB