rjr@mgweed.UUCP (Bob Roehrig) (07/02/85)
qst de k9eui hr propagation forecast bulletin nr 26 from arrl headquarters newington ct june 30, 1985 to all radio amateurs bt solar flux and sunspot number curves for june were quite similar to those for may, except that they were mostly a few points lower. this is to be expected, as cycle 21 will be 9 years old this week. the june flux average was 73.2. only march of this year was lower, with 72.5. the solar flux curve is presently above that for the same point in the previous solar rotation, but it is expected to peak more, probably early next week. anyone using 21 or 28 mhz regularly of late has found these bands busy, thanks to the seasonal peak in sporadic e layer ionization. because this mode is sporadic, and largely unpredictable as to timing, its effects are not included in the propagation charts that appear monthly in qst. e skip is good mainly for distances under 1200 mile most of the time, so it is not normally thought of as a dx medium. multiple hop effects can extend its useful range markedly during early summer. the 10 meter band has been open to europe from the east coast recently, and even austrailia and new zealand have been worked now and then. the possibility of transatlantic e layer dx on 50 mhz should not be overlooked, though it is quite rare this high in frequency, especially over more than about 2500 miles. propagation was erratic as this bulletin was being prepared. geomagnetic activity was rising, and rapid fading was troublesome. there should be some improvement later in the week but more disturbed conditions are likely again july 4 to 8. july 10 through 18 will bring more stability, and generally good summer propagation when electrical storms are not making noise a problem. american sunspot numbers for june 20 through 26 were between 1 and 16 with a mean of 7.1 ar