[NLRS] Upcoming AU and a few other notes

Wed, 29 Oct 2003 21:05:04 -0600

Mike,

I have noticed, with a sample of two auroras, that vertical polarization
WORKS!

The attached note is from SM5BSZ which explains that it only works
"sometimes".
url:  http://antennspecialisten.se/~sm5bsz/polarity/aupol.htm

Polarization of Aurora signals
There are a few statements that can definitely be made, and knowing the
facts help a great deal to get the pleasure of working many and distant
stations via aurora. Parts of these statements I think are well known, but
other parts I believe are more or less unknown to the amateur community. All
my observations are made from grid JO89, and there is of course a
possibility that the aurora propagation is different at other geomagnetic
latitudes.
1. In a north to south path, the polarization is always conserved,
regardless of the distance and intensity of the aurora. The easiest way to
work long distance to the south is to elevate the antenna during strong
auroras. The optimum elevation may be as high as 25 degrees during very
strong events.

2. Regardless of the communication path the polarization is always conserved
during minor auroras. An EME capacity station 1500km east or west will
always be horizontal, if the signal level is below S7 or so in the optimum
polarization plane.

3. During strong auroras the polarization plane is twisted, and the
polarization offset depends on aurora intensity and the east to west
component off the transmission path. (The polarization always stays linear,
but the best antenna direction may differ with different polarizations)

The statement 3 above is the important one: If you point a vertically
polarized array somewhere around 300 or 60 degrees in azimuth, the stations
within about 500km disappear, while the stations at 1500km become strong,
provided the aurora event is a good one. (From my QTH there are very few
stations at longer distances east or west).

* * * * * * * ** * * *
On tonight's aurora, I'm only working it with vertical polarization. So far
logged:
10/29/03
2347Z    K2ERG    FN13
10/30/03
0016Z    W9/G4FDX    EN60
0042Z    VE3AX           FN02
0112Z    K1TEO           FN31
0115Z    VE3EU           EN93
0116Z    K2RS             FN20
0118Z    WA1T            FN43
0120Z    W1JR             FN42

So far, vertical works!

Equipment:   single M2   2M8WLHD yagi, about 17dBd gain, 55 ft long, up 60
ft, and 1,000 watts out.

73,
Terry,  W0VB
0132Z    K2AXX    FN12
Please update your address book with my new email address of [email protected]
----- Original Message -----
From: "Mike A. King - KM0T" <[email protected]>
To: "Northern Lights Radio Society" <[email protected]>
Sent: Tuesday, October 28, 2003 10:08 AM
Subject: [NLRS] Upcoming AU and a few other notes

> Hey all,
>
> Been doing some tower maintinance here in EN13 and have had the tower laid
> down for the last week.  Been working on the 3456 transverter box, etc.
etc.
> Fixed a relay control cable that the rabbits chewed thru...was sending 150
> watts of 902 Mhz to the 1296 antennas...that did not work so well, but its
> good now.  Also, apparently for the last year or so, I have only been
> getting about 2 watts to my 3456 Mhz loopers.  So, those of you who
thought
> I was stronger before, were right.  However, I still worked everyone that
> was tried!  Goes to show you if you all get those 40 watt Toshiba amps
> going, what kind of damage you can do!
>
> Anyway, it does not look good for getting it back up for this prehaps
> "unprecedented" AU opening that we may have.
>
> I do however have my dish tower, which has a 144 MHZ yagi on it, but it is
> VERTICALLY polarized for FM.
>
> I dont mind running the SWR a bit high, but I was wondering if anyone out
> there has any real data on using a Vertically polarized yagi for AU event.
> I recall speaking with Terry, W0VB about it as he was working on his array
> and was going to give it a go.  I believe Terry indicates it works for
long
> haul, but cuts out the local QRM due to the polarization cancellation.
>
> Terry, if your reading this, have you tried it yet and have anything to
> indicate yet?  Also, anyone else have comments?
>
> Being so windy down here, not sure if the tower will get back up, but I
can
> fire up the other one!
>
> If this turns out to be anything like the Persieds meteor shower AU event
a
> few years ago (where everyone was on to work the meteor shower - but the
AU
> was so awesome, it did not matter!)  then we should be ready to take
> advantage of it!
>
> 73
>
> Mike - KM0T
>
> Oh- Congrats Pat on the award!  Just by coincidence yesterday as well, I
> finally got my ARRL 2001 2nd place Single Op HP plaque for the June VHF
> contest.  It took a long time, but was worth it!
>
> Had a good time at the hamfest and at the NLRS booth, thanks to all who
put
> it on!
>
>
> _______________________________________________
> NLRS mailing list
> [email protected]
> http://mailman.qth.net/mailman/listinfo/nlrs
> ----------------------------------------------------
> This message has been processed by Firetrust Benign.
>