[TowerTalk] Re: Horizontal + Vertical Polarization Question
Jim Lux
jimlux at earthlink.net
Fri Nov 21 10:38:17 EST 2003
At 09:17 AM 11/21/2003 -0800, Ward Silver wrote:
> > AA6E writes:
> >
> > It would be very interesting(!) if someone were to actually measure the
> > incident polarization of typical skywave signals (actually, someone
> > probably has.. the radio astronomy folks working at HF have to deal with
> > nulling out interferers, etc., and I'm sure some one in the SW broadcast
> > business has looked at this), particularly in terms of the short time
> > statistics.
>
>This was extensively investigated in the 1930's through the 1950's. I
>believe the BBC and British Defense engineering staffs did a lot of the work
>since they of farflung empire "over which the F-layer never de-ionized"
>needed reliable HF links over very long paths - like from London to
>Auckland. There were a number of reports and even books published on the
>topic. I suggest looking through the archives of the IRE for the
>appropriate info.
>
>73, Ward N0AX
I have found some stuff online from the 70's or so. Incident noise power
statistics, etc.
For the long distance HF links (which the US did too... my father worked at
the Far East Network in Japan in the 50's), I think they also just relied
on BIG antennas (rhombics and curtains) and BIG transmitters and just piled
up enough link margin so cross polarization was immaterial.
I'll keep poking around, but, you get far enough back and it's not online,
except titles and authors, which doesn't always cover the need. However,
sometimes, the paper from the 70's will have a reference to the paper from
the 40's and 50's, and then I can request that from the library.
The other thing is that a lot of this sort of thing got (and still does)
published as "technical memoranda" or "technical notes", rather than in
journals, being considered mere "engineering data". The indexing of this
is much more sparse.
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