[Fwd: Re: [NLRS] Two Meter Aurora Observations using Vertical Polarization (long)]

[terryvb@starband.net]

Jon,

Thanks for your interest.  At the end of this note is a request for your
thoughts, as well as others on the NLRS reflector, of what experiments I
can try this evening.

The reason for my report is to get some feeling as to what the band was
like for others.  To see if this was a so-so aurora at the times I was
on..... or was it just as huge as I was experiencing?

My baseline changed for this aurora and I don't have much of a clue for
comparison.

Here's what changed on my end:
1.) Wired in a Kenwood TS-2000X replacing my TS-850SAT with DEMI 144/28
Mhz transverter.

2.) My horizontal 2M8WLHD 55ft beam is not working right now. I replaced
my two original 2M8WL yagis with the new heavy duty yagis now being sold. 
One is horiz and one is vert polarization on a crossboom with an elevation
rotor. All worked flawless on the ground, but when installed, the horiz
beam hasn't worked very well since. However, I'm currently focused on
getting six - M2 2MXP28 yagis up before "real" winter arrives.

Based on the data I referred to in SM5BSZ's write up, I was interested in
seeing what experience one could gain by using a high performance
vertically polarized antenna in an intense aurora. Here's what was
observed:

1.) The intensity of what I heard was at times S9 or better but lasted for
brief periods. While vertical, and hearing good signals, very few signals
within 700 miles were heard, if there - they were weak! (not much QRM) but
I experienced QRM from the W1's and W'2s.......

2.) My heading was 63 degrees most of the time but I heard CO, WY, and SD
very well aimed east. I didn't call them.

3.) When I switched to the poorly working horizontal 55 ft yagi, the
signals peaked at a beam heading of around 45 degrees!  Not the 63 degree
heading I was using when working the east coast.

I can elevate so perhaps that will be tried this evening.

*****
Looking for your two meter data for comparison at the times I reported
making the contacts last evening.....

*****
If you have suggestions on what I could try this evening with this
installation - let me know!

73,

Terry, W0VB


-------- Original Message --------
Subject: Re: [NLRS] Two Meter Aurora Observations using Vertical
Polarization (long)
From: jcplatt1@mmm.com
Date: Thu, October 30, 2003 10:42 am
To: "Terry Van Benschoten" <w0vb@arrl.net>


Terry, the question about vertical polarization is actually three
questions (at least !).

One question is what happens with polarity during AU propagation  ....
is it preserved ?   Most VHFers are using horizontal polarization.   I
think your earlier post goes towards addressing that.

A second question may be would vertical polarization propagate via the
aurora better than horizontal polarization ?   I haven't a clue, but I
have heard of some east coast stations doing some work on this some
years back and finding that there was basically no difference .... that
as long as both stations were using the same polarity that the signal
strengths via AU were the same (of course, this is all hearsay on my
part, because that's all I remember !).    I'm not sure if they tried
any really long paths. Does anyone know of any papers on this question ?

The third question is given any fixed antenna at a fixed height, for
best performance, should it be horizontal or vertical ?    Due to ground
interaction when vertically polarized, a yagi will have more gain in its
first main lobe when its horizontal.   If "performance" is gain, then
horizontal is better.

However, because of that ground interaction for vertical polarized
antennas, the nulls between the lobes is smaller (ie; filled) for
vertical polarized antennas.    For example, a 5 ele 2m yagi that I
modeled using EZNEC mounted at 20' above real ground has a first null of
only -6 dB down while the same antenna mounted horizontally and at the
same height above ground has a first null of -27 dB.     When the
antenna is mounted higher the null on both antennas deepens but the null
on the horizontal antenna is always deeper.    What this might mean is
that for large AU events like we had last night, as the AU moves south
and elevates for us, that for an antenna at a given height above ground
it may be better to be vertically polarized from the standpoint of
staying out of the first null (which is very deep on the horizontal
polarized antenna).   Another alternative is to have a lower horizontal
antenna that has a higher take-off angle.

I think that the aurora was pretty far south last night.   I noticed
that N0UK thought that it was going pretty good, and I heard him working
a bunch of stuff on 2m, but I thought it was kind of hard to work people
.... I called CQ and with few takers, and I would call people who were
calling CQ who were S5 to S7 and get CQ'ed in the face again.   I run
800 watts out and my single 2m yagi is at 50'.   I think N0UK runs about
400 watts but his antenna is lower .... perhaps having a lower antenna
was an advantage this time (due to the higher take off angle and the
higher first null)

The other thing that makes me think that the AU was south (elevated) for
us was that signals peaked on a very broad heading for me ..... I think
this is a sign that the signal is arriving at a high take off angle
where the antennas performance is degraded.   The bearing is broad
because the antenna performance at those high angles is broad and
nothing like what we normally experience for normal low take-off
signals.

Regarding what I worked, I spent some time on 6, 2, and 222 and did a
lot of tuning around.   On 6m the best DX was to VE9 (NS) .... the
interesting thing about this contact was that it was on SSB with no
distortion (no Au tone).   On 2m I worked from NE & KS thru KY to NY and
PA.   On 222 I only worked two stations, one in IN and one in IL.    I
did hear K1TEO weakly on 222 and gave him a call but no contact was made
..... I suspect that he may have been running more power than my 100
watts.

Should be some more Au action for the next day or two.

73, Jon
W0ZQ