Comparison of MUF, FOT and LUF for various antennas during a low
sunspot (SSN10) using the AN/GRC-142 (400 watts), RATT.
Unlettered frequency indicates 90 percent, B 80-90 percent, C 60-80
percent, D 40-60 percent, E 20-40 percent, F 0-20 percent reliability.
Transitional frequencies every 2 MHz between the night and
frequencies will be needed to maintain 24-hour communication.
Using a 15-foot whip you can expect 53 percent reliability for a 24-
Using a 32-foot whip you can expect 87 percent
reliability for a 24-hour period. Using a doublet, sloping (quarter
wave), or inverted vee you can expect 90 percent reliability for a
24-hour period. Six frequencies should be available, anything less,
reliability will decrease.
A change in frequency at other than the
time indicated will vary. There will be times when fewer frequencies