ad7i (04/20/83)
qst de ad7i holmdel, new jersey, u.s.a. hr propagation forecast bulletin nr 16 from arrl headquarters newington ct april 18, 1983 to all radio amateurs bt after three weeks of the lowest solar activity in five years, the solar flux is rising slightly again. it reached 113 on the 17th and should go somewhat higher before turning down again in a few days. geomagnetik activity was lower as this bulletin was issued, so somewhat better conditions and slightly higher muf can be expected about april 20. higher geomagnetic activity is due briefly around april 21, and over a longer period beginning about the 24th. this will degrade conditions on all dx frequencies. propagation will improve near the end of april, carrying over into early may, mostly on low latitude and transequatorial circuits. high latitude f layer dx is about over on 28 mhz until autumn, but increased e layer ionization will produce short skip on 28 and 50 mhz, mostly at distances of 500 to 1200 miles. multiple hop effects will be more common in july, increasing the communications range to 2500 miles or more. at the height of the e layer season there will be skip propagation even on 144 mhz at times, notably in june and july. american sunspot numbers for april 7 through 13 were between 58 and 67 with a mean of 61.9 ar