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HF MAGIC VERSION 1.0 DOCUMENTATION


1. INTRODUCTION

HF MAGIC 1.0 is an HF propagation prediction program which is
different from those available from other sources today. This program
is designed for use by the amateur or shortwave listener who wants to
maximize communications over "practical" HF distances, generally up to
2500 miles in length. It not only presents the maximum usable
frequency (MUF), which is only part of the story, but computes the
received signal strength in "S" units including the very important
contribution of "D region absorption". This factor is often missing
from propagation models, but is very important in determining total
signal strength during the daytime hours. The program is based on
MINIMUF and NBS absorption expressions.

The outstanding features of this program include very compact
size and rapid execution.


2. PROGRAMS

The program package consists of 4 files:

HFMAGIC1.FNL main BASIC program

MAGICSRC.BAT batch for screen output

MAGICFIL.BAT batch file to send output to a file

MAGICPRT.BAT batch file to send output to line printer

The version which provides only screen output can be directly
executed by entering the command: BASICA HFMAGIC.FNL . The file
version will load the output into a file A:MAGICOUT.FIL; you can edit
the batch file MAGICFIL.BAT to create the output file on any desired
drive or directory.


3. INPUT DATA REQUIRED

The program will issue prompts for all required data.

The first prompt will be for which version of the program is
desired; enter 1 if you desire S-meter predictions for the 5
traditional ham bands (80,40,20,15, and 10 meters); enter 2 if you
desire 9 bands (5 traditional plus 160, 30, 18, and 12 meters); enter 3
if you desire the computation for arbitrary frequencies which you can
input; and enter 4 if you are only interested in MUF predictions.

The next prompt will ask for the number of solar flux points
and increment. This permits you to have multiple runs which can be
referred to in order to evaluate the best band to use for a particular
set of solar flux conditions. If only a single run is desired, enter
1,1 at this prompt.

The next prompt will ask for the number of runs to be
executed. If you desire computations for more than 1 set of
conditions, enter the appropriate number here else 1 for only a single
set of conditions.

The fourth prompt will ask for the details for the path being
computed. This data should be entered with a comma between each number
as a delineator. The data consists of the latitude and longitudes of
the two endpoints of the path (in degrees and decimal degrees, north
and west positive), day of the month as a number, month as a number,
the starting value of solar flux (if multiple flux values are being
computed, else the particular flux value desired for the computation),
and a field of alphanumeric characters to document the run (these will
be printed out on the output). Current values of solar flux can be
determined by listening to station WWV or WWVH (2.5,5,10,15,20 Mhz) at
18 minutes past the hour.

After completion of the data entry, the entered parameters
will be echoed back for confirmation. Hit enter if the string is
correct.

4. OUTPUT

The output will consist of a matrix of time, frequency, and
signal strengths (in dB over/under S-9) based on the assumption of 100
watts transmitted and the use of non-directive antennas such as
vertical and dipole antennas. A value of -98 in the output indicates
that the band will not be open, and a value of -99 indicates very high
D-region absorption. The normal range of useful communications will be
down to an amplitude of -54, corresponding to 54 dB below S-9, or S-0
(an S unit is 6dB by convention). An output of 20 indicates a signal
level of 20dB over S-9.

The time presented is Universal Time (UT), based on the local
time at the prime meridian at Greenwich, England. Remember to convert
this time to your local time.


5. ACCURACY

Most people who have used this program have reported that the
predictions match the actual conditions with a reasonable degree of
accuracy in predicting the best band to use and the signal strengths
which will result. The accuracy is quite good for distances up to
about 2500 miles.


6. COMPENSATION

Disemmination of this program via BBS systems is encouraged
so that many people can use it. If you feel that this program is
useful for you, please send a token fee ($10 suggested) to:

Dick Lodwig W2KK 2201 Duvall Rd. Woodbine, Md. 21797


7. EXAMPLE OUTPUT

An example output for the case of a Maryland to Florida path
on the 27th of February with a solar flux of 200 is provided below.
Note that for communicating at midnight Eastern time (5 UT), the 160
thru 30 meter bands will give a path, but since the atmospheric noise
is much larger for the lower bands, the 40 or 30 meter bands will give
the best results.

For communicating at noon Eastern time (17 hrs UT), the 20
thru 12 meter bands will all give equivalent results and the choice of
band can be made based on equipment capabilities and QRM observed on
the bands.

------------------------------------------------------------------------


ENTER:
1-5 VAL SM
2-9 VAL SM
3-ARBITRARY SM
4-3 VAL MUF
? 2
ENTER NUM OF SF PTS,INCREMENT
? 1,1
NUMBER OF RUNS
? 1
STR FORMAT LAT,LON,LAT,LON,DAY,MO,SF START,ALPHA TITLE
ENTER STRING NO. 1
? 39,77,23,80,27,2,200,Md-Fla

FLUX PTS,INCR 1 1
INPUT DATA STRINGS
39 77 23 80 27 2 200 Md-Fla

PRESS ENTER TO CONTINUE?

HFMAGIC 1.02 FOR Md-Fla BY W2KK.

DATE: 27 FEB
TRANSMITTER LOCATION
LATITUDE 39 LONGITUDE 77
RECEIVER LOCATION
LATITUDE 23 LONGITUDE 80
SUNSPOT NUMBER= 155 SOLAR FLUX= 200 (WWV AT HR+18 MIN)


RECEIVED SIGNAL FOR 100W TRANSMITTED. PERFECT
NON DIRECTIVE ANTENNAS. DB OVER/UNDER S9

UT FREQUENCY
HR MUF 1.9 3.8 7.2 10.1 14.2 18.1 21.3 24.9 28.5
-- --- ---- ---- ---- ---- ---- ---- ---- ---- ----
0 20.4 19 13 7 5 2 -1 -98 -98 -98
1 17.8 19 13 7 5 2 -98 -98 -98 -98
2 16.3 19 13 7 5 2 -98 -98 -98 -98
3 15.0 19 13 7 5 2 -98 -98 -98 -98
4 13.9 19 13 7 5 -98 -98 -98 -98 -98
5 13.0 19 13 7 5 -98 -98 -98 -98 -98
6 12.3 19 13 7 5 -98 -98 -98 -98 -98
7 11.7 19 13 7 5 -98 -98 -98 -98 -98
8 11.1 19 13 7 5 -98 -98 -98 -98 -98
9 10.7 19 13 7 5 -98 -98 -98 -98 -98
10 10.4 19 13 7 5 -98 -98 -98 -98 -98
11 13.0 -4 7 6 4 -98 -98 -98 -98 -98
12 19.2 -99 -21 -2 -0 -1 -2 -98 -98 -98
13 22.6 -99 -54 -11 -5 -3 -3 -4 -98 -98
14 24.7 -99 -85 -20 -9 -5 -5 -5 -98 -98
15 26.2 -99 -99 -27 -13 -7 -6 -6 -6 -98
16 27.2 -99 -99 -32 -16 -9 -7 -6 -7 -98
17 27.7 -99 -99 -35 -17 -9 -7 -7 -7 -98
18 28.0 -99 -99 -34 -16 -9 -7 -7 -7 -98
19 27.9 -99 -99 -30 -15 -8 -6 -6 -6 -98
20 27.4 -99 -99 -24 -11 -6 -5 -5 -6 -98
21 26.6 -99 -69 -15 -7 -4 -4 -5 -5 -98
22 25.3 -99 -37 -6 -2 -2 -3 -4 -4 -98
23 23.4 -54 -5 2 2 0 -1 -3 -98 -98

GRT CIR DIST= 1800 KM 1125 STAT MILES 978 NAUT MILES.
PATH MIDPOINT= 78.6 LON 31 LAT

HFMAGIC 1.0 COPYRIGHT W2KK 2201 DUVALL RD. WOODBINE, MD 21797
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