"christofire" wrote in message
...

"Jerry" wrote in message
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- snip -


I have problems with believing there will be any current in either
dipole. What am I missing?

Jerry KD6JDJ


That's understandable.

Chris

Hi Chris

Tell me, did you guys ever decide that there would be a far field
generated by the spinning dipole with DC on it? I dont refer to the
inductive field.
Maybe there is no way to separate Far Field from any condition where an
inductive field is generated.

Jerry KD6JDJ


Jerry,

I think you're right - in the far field there is spherical spreading of
power without regard to separate magnetic and electric components that an
antenna, of whatever form, might produce. Of course the radiated power
incident on any surface can be represented by an equivalent value of
electric or magnetic field strength but this is on strict understanding
that the counterpart (magnetic or electric) component is present with the
requisite field strength (E/H = Zo = 377 ohms in free space) and PFD =
E2/Zo.

The answer to your first question is 'yes - hypothetically' there 'would
be a far field generated by the spinning dipole with DC on it' but this
shouldn't be taken as a recipe for some wacky rotating machine. As I
outlined earlier, there is probably little practical application for this
interesting analogy because if it were ever put into practice it would
probably be hopelessly inefficient and transformation of Maxwell's
equations into an inertial frame spinning at the radio frequency is hard,
to say the least! As has been suggested, it's probably best to take the
concept no further than an interesting thought exercise - if you don't
understand that, don't worry, you're not missing much

Chris

Hi Chris

Thanks for the reply.

Yeah, I never ascribed any practical use to the "CP by spinning". But,
there are some fundamentally good thoughts generated here. For instance, I
can easily see why two dipoles rotating at the same rate and rotational
direction will couple *nothing*. Thats like trying to receive RHCP with a
LHCP antenna.
I have lived a long time without understanding Poynting and Maxwell
(almost 100 years older than me), I wouldnt want to change that now.

Jerry KD6JDJ