[Elecraft] cobweb antenna
Joe Subich, W4TV
lists at subich.com
Sat Jun 1 13:46:06 EDT 2013
Whether the field is predominately magnetic or electric, it must
still couple to the environment around it or the antenna *will not*
radiate. whilst the same folding that is responsible for the low
feed impedance and low efficiency will result in more cancellation
close to the antenna than at greater distances, the antenna will
still have *significant coupling* to any conductive element in its
immediate environment (near field). If that were not true, yagi
antennas would be impossible and phased arrays would be easy to
design because one could ignore mutual impedance.
73,
... Joe, W4TV
On 6/1/2013 6:23 AM, David Woolley (E.L) wrote:
> Joe Subich, W4TV wrote:
>
> The near field (basically within the range where it follows an inverse
> cube law) can be predominantly magnetic or predominantly electric in
> nature. Whilst the ratio of electric and magnetic fields in the far
> field is constrained to 377 ohms per square, that is not true in the
> near field.
>
>>
>> No. If the field is not able to couple to nearby objects, it is not
>> able to radiate (couple to) distant receivers. The statement flies
>> completely in the face of physics.
>>
More information about the Elecraft
mailing list