[TowerTalk] Combining ant elevation pattern data with propagation
predictionsto produce a contest bandplan
jimsmith at shaw.ca
Thu May 22 01:54:05 EDT 2003
Wow, thanks for all the responses.
Don't be too hard on me for things like saying SFI instead of SSN and
suchlike. I know virtually nothing about propagation and the terms
associated with it.
A number of issues were raised
1. The models used for predictions contain statistical data, thus there
is no possibility of guaranteeing that a particular path's predicted
characteristics will be accurate or even that the path will exist at all.
I understand and accept this. However, it's kind of like reading
semaphore signals in the fog. If the fog is too thick, you won't see
the signaller. If it's somewhat thick you may be able to see him but
not make out 100% of what he is sending. No fog, no problem. BUT if
you're facing the wrong way you will never see the signaller, fog or no
fog. I'm looking to the predictions to tell me which way to face.
2. The models are based on smoothed numbers. The daily SFI/sunspot
numbers you get are not smoothed so aren't the right values to use.
On a 6 hourly basis you can get Effective SSN based on real time FoF2
The USAF provides forecasts about a month ahead of K and SFI values.
Presumably these forecasts improve on the model, else why would they
bother. I think the forecast is for a longer period than the 27 day
rotation period of the sun.
IPS in Australia provides Hourly Area Prediction charts centred on any
location you choose. It shows what I presume to be Optimum Working
Frequency (it tells you on their website) to any point on the chart.
Why are they doing this if it doesn't mean anything on a particular day?
What I'm trying to say here is that it looks to me as if people are
doing meaningful path predictions (and others are buying them).
3. What's the point? No matter how good the prediction, a CME can blow
it all away.
See fog above
4. The models are guides only, openings may begin or end earlier or later.
I understand this. Just means I have to keep an eye on things. At
least I'll know where to look and what to look for.
5. Just because a path is open doesn't mean that there are Qs to be
made because a) there's no one there b) they all have their beams
pointing sideways to you working a different opening
a) I didn't mention it because I was trying to keep things simple. The
FOM includes the number of stations reachable via that path who entered
the contest last year.
b) Sad but true. I guess experience is the only teacher here. Say, I
could also plot paths for each location I'm trying to reach to see what
they're likely to be working.... oops, sorry, got carried away there.
6. What style of contesting do you engage in? It makes a difference in
how you approach this stuff.
At home I'm typically SOAB LP with very limited antennas. However, I
also want to use this for Field Day to help select antennas to use and
also generate band plans for each op position. A lot of our ops' only
exposure to HF is on FD so have no clue what band they should be on, let
alone what bands exist. I'm hoping this will give us info based on more
than hunches. Obviously, we have to be prepared to modify the plans
based on what is actually happening.
7. Forget the database stuff, put the work into antennas and have fun.
This may well be the best advice of the lot. However, I'm a stubborn
old fool and have trouble letting go of things. Besides, I'm horrified
to see how badly atrophied my Access skills are so this is a good
exercise for me.
8. Do a little work to get that feminine side happening better.
Don't know what to say to this. ROFLMAO?
9. A number of programs were suggested which may either do what I want
or help me get there. Also, several referred to N6BV's work on arrival
angles. Thanks for the great suggestions. It will take me a while to
try them all out.
Thank you all very, very much for taking the time and trouble to help me
out. I know very little about any of this stuff but this project is, if
nothing else, a great learning experience.
73 de Jim Smith VE7FO
PS Look for my trainee calling CQ at 10 wpm in WPX, Sat, between about
Jim Smith wrote:
> I've been having a lot of fun trying to come up with a way of deciding
> what band I should be on at what time in a contest. I'm sure many far
> more successful contesters than I do it from experience and intuition.
> Not having a strong feminine side (anal, she called me) I try to use
> logic and science as much as I can.
More information about the TowerTalk