Over the weekend I took pictures of some longwave antennas used by
local aeronautical beacon stations around 270 kHz. I mention them here
since similar antennas are used on 160M and it may give some people
some new ideas. The pictures can be seen at:
[hit "View Photos," then "Launch Viewer"]
Most of the LW beacons in the state of Nebraska use T antennas similar
to those shown and used by stations JYR and SWT. The vertical section
of their T antenna is 17M tall and it would make a reasonable topband
antenna with little change.
But, the noteworthy antenna is that used by AUH in Aurora, NE. It is not
a very commonly used antenna. It has a 16M tall square cage of 12 vertical
wires surrounding a wooden pole support. At the top of the vertical cage
of wires, the wires turn into 12 top-hat wires and run to a ring of 12 6' tall
smaller diameter wooden poles surrounding the taller center pole. The ends
of the top-hat wires are all connected together by a wire which forms a circle
around the now large top-hat wire cage (I think that they made a mistake
in adding that outer ring). Again, this LW antenna would make an effective
160M antenna at a reasonable price. My 160M driven element is a variation
of this idea: Four 1/4" tubing "wires" surround my 28M tall tower with a
HF Yagi serving as its top-hat...
Hopefully, these LW antennas will spark some topband antenna ideas for a
few of you.
73, Bill K0HA