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

Jim Lux jimlux at earthlink.net
Wed May 21 08:02:59 EDT 2003

Propagation predictions can come from VOACAP (ITSHF is the name of the
package, and it's free from NTIA to download).  There was an article about
VOACAP (which is, by the way, based on the old IONCAP engine, which produced
the takeoff angle charts in the ARRL antenna book).

VOACAP (and ICECAP, which is part of the same package, and might actually
work better, for a variety of reasons), model both the transmitting and
receiving antennas.  You can either specify a library antenna, or read the
pattern in from a file, bringing me to the next suggestion.

4nec2, which is a very nice (free) Windows front end on NEC, will parse the
NEC output file and generate the antenna input file for ICE/VOA/IONcap.

Bear in mind that the VOACAP ilk are statistical prediction programs (you
put in time of day, year, and SSN and get a variety of data out), intended
for broadcast or fixed link station planning: "Where do I point the curtain
array to cover West Africa with 99% coverage?" kinds of questions.and not
intended for "real-time" prop forecasts.

The Australians have some very nifty (but not free) programs to do real-time
forecasts.  HF comm is still very commonly used in the Outback, where there
are no wires, no cell sites, etc....

----- Original Message -----
From: "Jim Smith" <jimsmith at shaw.ca>
To: <towertalk at contesting.com>
Sent: Wednesday, May 21, 2003 1:25 AM
Subject: [TowerTalk] Combining ant elevation pattern data with propagation
predictionsto produce a contest bandplan

> 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

> Is there an affordable program which will combine propagation
> predictions and antenna characteristics and tell me, for any path of my
> choice on any HF band, the likelihood of making Qs on that path?
>  Affordable?  $100    Not Affordable?  $500
> Please don't ask me how I'm doing this.  This is a work in progress and
> time spent answering how-to questions takes away from the time available
> to do the work.  Hope I said this in an acceptable manner.
> 73 de Jim Smith    VE7FO

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