[NLRS] Aurora watch

[jcplatt1 at mmm.com]

Hi Tom and welcome to VHF.   Here is the briefest of tutorials on aurora.

When:   Aurora is seasonal with the peaks happening during the solar
equinox, both Spring (mid March) and Fall (late Sept), +/- a couple of
months.    Its somewhat rare to have aurora during the middle of summer or
the middle of winter.     It also occurs opposite the sun (more or less),
like say 3:00 PM local to 11:00 PM local, then again in the early morning
hrs.    There can be a tendency for it to disappear around midnight local
time, but if the aurora event is a strong one, watch for auroral E to occur
at this time.   In summary, the best time to watch for aurora is in the
Spring and Fall and during the late afternoon through the evening hours
then again in the early morning hours before sun rise.

Bands:   You will find the strongest signals on 6m and 2m.    I find that
when signals are S5 or better on 2m, that I can work aurora on 222.    My
experience is that 222 is about two-thirds as good as 2m for working aurora
.... lots of fun.     I have worked only two or three aurora contacts on
432 and they have been fairly short distances.    There are lots of folks
playing on 6m when there is a good aurora going.

Modes:   Because the earth is moving under the aurora, and because the
aurora is not fixed but in flux, there is "distortion" in signals that are
reflected off the aurora .... I think most of the distortion is caused by
Doppler shift.   The effect is that SSB signals sound raspy and CW sounds
like keyed noise (its not a pure tone any more).   Its very distinctive
once you have heard it.     Because Doppler shift is a function of
frequency, this "distortion" gets worse as you go up in frequency (from 6m
to 2m to 222).   When the distortion gets bad enough, SSB signals get to be
hard to understand and most people go to CW.    On 6m, you can usually work
SSB as the distortion isn't too bad, especially if you talk slowly.    Its
my experience that you will find both SSB and CW contacts underway on 6m
during an aurora.    By the time you get to 2m, the distortion is pretty
bad and its been my experience that 95% of all 2m aurora contacts are on
CW.    Yes, you can make 2m SSB aurora contacts, and sometimes they are not
to bad, but often you can't ..... to much distortion.     I have never made
a 222 SSB aurora contact but I know that there are some who have ..... my
thoughts are why try, grab the key and go to CW.   CW has a place in weak
signal VHFing and most Op's are OK with slow CW.

Freq:   On 6m, most people are listening to 50.125.    Its poor operating
etiquette to rag chew on this freq.    Call CQ, if you establish a contact,
then QSY up the band several ten's of KHz to say 50.150 or 50.160.
During an aurora event, the band is often utilized from 50.125 up to 50.200
and above.    I usually avoid calling CQ from 50.125 to 50.100 as this is
more of the international DX freq range .... if I find someone calling CQ
in that area that I need (like Wyoming or something), I will call them !
50.100 and below is CW only and most 6m CW contacts occur in the high end
of this range, like 50.100 to 50.090.

Equipment:   You can make aurora contacts with 25 watts, but 100 watts is
better.   You will have lots of fun working aurora if you can get to that
75 to 150 watt range.    A gain antenna is needed, even a small yagi.   3
or 4 elements on 6m and a 12' boom yagi on 2m (or larger).

Where to point:   The aurora is centered on the magnetic pole which is NNE
for us.    Therefore point your antennas at about 15 degrees or so.    As
the aurora gets stronger, it moves, both north/south and east/west, so play
with your beam heading for maximum signal strength.    During a strong
aurora opening I have worked 2m stations in NY/NJ/PA, etc., where my beam
heading was about 80 degrees .... same thing going west.    Start by point
NNE.

Hope this is helpful.   There are some very good books on this subject and
you can find a bunch of stuff on the internet as well.

73, Jon
W0ZQ