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Old December 8th 08, 08:11 PM posted to rec.radio.amateur.antenna
Jerry[_5_] Jerry[_5_] is offline
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First recorded activity by RadioBanter: Jun 2008
Posts: 133
Default Circular polarization... does it have to be synchronous??


"christofire" wrote in message
...

"Jerry" wrote in message
...

- snip -

I am having a block in my learning. As I understand it, this would
actually happen if it could be performed.


Yes


A spinning dipole would require more power to spin it if it had DC on it
than if it had no DC on it.


Yes - as I said, the means of spinning the dipole would be the counterpart
to the 'transmitter'

And, actually, it would require no power to keep the dipole spinning
since there would be that theoritical vacuum around it.


If you say so - you're specifying a hypothetical zero-friction system
which is but one of several possible scenarios.

But, once you apply the DC, power would be required to keep it spinning.
That amount of added power would be determined by the amount of DC
applied. Do you confirm that this is true?


Certainly work would need to be done to spin the dipole and create the
outgoing wave by virtue of its rotation. I suppose it follows that the
strength of the outgoing wave would be proportional to the applied voltage
but I'm not certain that a greater voltage would require more mechanical
work to spin the dipole - you may be right but I'm not certain I can
confirm this from what I think I know!

My question relates to my ignorance about what there is in the "vacuum"
to cause "drag".

Jerry KD6JDJ


I'm afraid I had taken very little account of causes of mechanical drag.
As noted before, this was a thought experiment - the sort of thing that
can reach a useful conclusion (i.e. 'not likely' in this case!) without
requiring detailed examination of what may be 'second-order' influences.

Chris


Hi Chris

I accept as valid, your statement that the dipole with DC will radiate a
far field when spun. I have a mental block related to questioning what
makes it harder to spin when the DC is increased.
Yes, I do consider the media in which the dipole is spinning creates no
friction. I do wonder what makes it harder to spin when the DC voltage is
increased.

Jerry