[TowerTalk] Combining ant elevation pattern data with propagation predictionsto produce a contest bandplan

Jim Smith 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 
observations from
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.

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