[Elecraft] Less Than Perfect Antennas [was Flumoxed]

[Don Wilhelm]

Robert,

That depends on what you want to achieve.  If it is more gain broadside 
(perpendicular to the antenna) then the answer is yes.  On 80 meters the 
160 meter elements alone will be Two Halfwaves in Phase and will have 2 
to 3 dB of gain broadside to the antenna.

Of course, that gain comes at a cost of radiation in other directions. 
L.B. Cebik (SK) explained it best - if you visualize the radiation from 
an isotropic antenna as a balloon, then squeeze that balloon so the 
largest projection is in the direction(s) of the gain, you will see the 
reduction of gain in other directions.  In other words, there is no free 
lunch.  For the dipole, squeeze the balloon in the middle a bit, and for 
2 half-waves in phase, squeeze it a bit harder.
If you want to achieve the maximum squeeze, change the length of each 
half of the radiator to 5/8 wavelengths and you will have the greatest 
broadside gain before the radiation pattern breaks into multiple lobes.

You can find that basic information in most any good antenna handbook. 
It is the basis for all wire gain antennas.

For rotatable arrays or other directional switchable arrays, that 
balloon effect is exactly what is desired, but for a fixed wire antenna, 
that balloon effect may not be desirable if you want to work stations 
that are off the ends of the antenna.

So the answer is -- it all depends.  Do you want to orient your antenna 
to favor certain locations, or do you want something more or less 
omnidirectional.  An Inverted Vee will be slightly more omnidirectional 
than a horizontal dipole.  A vertical is an omnidirectional antenna with 
a circular pattern, but normally with a lower take-off angle than a 
dipole at a modest height.

If you want to work nearby stations as well as those further away, use a 
dipole - if you want to work DX (which usually comes in at low elevation 
angles, use a vertical.

73,
Don W3FPR

On 12/8/2018 10:03 PM, Robert G Strickland wrote:
> Ron...
> 
> Would such an antenna cut for 80m, fed with ladder-line, and used on 
> 40m, be a better performer on either band than an 80-40m fan dipole fed 
> with 72ohm coax? Leaving all other extraneous but influencing parameters 
> aside. I have the second antenna; the weight of all that wire and the 
> coax with a ferrite balun results in a significant sag. I'm wondering if 
> the first antenna, lighter and higher in the air, would perform better? 
> Thanks.