‰ Now 18 WPM transition file follows ‰

There wasnt much change this week from last, with average daily
sunspot numbers down slightly, less than five points to 14R6. This
doesnt result in high enough MUF values to see much propagation on
the highest HF bands, such as 10, 12 and 15 meters. But even with a
low MUF, there is still occasional long distance propagation on 10
and 6 meters. Larry Godek, W0OGH of Gilbert, Arizona says he
monitors 6 and 10 meter FM all day. Larry scans many channels on
both bands with multiple receivers. On 29R62 MHz, he often hears
W1OJ in Boston and another repeater in Florida, although not so much
recently. Lately he hears quite a bit of W5DFW in Dallas on 29R66
MHz. On Tuesday, July 25 Larry was hearing W5DFW, alternating with a
California station. On the same day he heard a repeater on 53R09
MHz, but didnt catch the ID. He suspects it was in Oklahoma or
Texas. He also heard stations near Sacramento, California. For
parsing those mystery signals, Larry wishes he had a database of six
and ten meter FM repeaters that he could sort by frequency.
Ideally, it would cover all of North America, so he wouldnt need to
look through separate state lists. Joe Alvin, KB1JVW of White River,
Vermont asks for some comments on how current sunspot numbers affect
MUF, or Maximum Usable Frequency. Generally MUF is lower with lower
sunspot numbers, but there is quite a bit of variation depending on
where the two ends of the communication path are located. For
instance, from Joes location, the MUF recently, calculating from
average sunspot numbers using a propagation prediction program, on a
path to Germany would vary from 13R3 MHz at 0300z to a peak above 17
MHz from 1500 to 1530z and 1830 to 2030z, and up to 17R4 MHz around
0000z. But with the same sunspot number on the same date, the path
from Dallas to Costa Rica would show an MUF that peaks above 24 MHz
from 2330 to 0230z and dips below the 20 meter band around 0900 to
0930z. A few years from now, if the sunspot number rises to around
100, that path from Dallas to Costa Rica would peak above 28 MHz
from 1730 to 2200z and around 0200. Sunspot numbers were 14, 12, 0,
21, 19, 16 and 20 with a mean of 14R6. 10R7 cm flux was 72R2, 72R6,
73R6, 76R5, 77, 75R5, and 74R7, with a mean of 74R6. Estimated
planetary A indices were 3, 2, 4, 4, 4, 6 and 6 with a mean of 4R1.
Estimated mid latitude A indices were 2, 1, 3, 4, 7, 5 and 5, with a
mean of 3R9‚

‰ End of 18 WPM transition file ‰