VHF PLUS

Weather systems in late summer and early fall often result in tropospheric propagation on the VHF and above bands. Slow or stationary high-pressure systems can result in what is called high-pressure tropo or subsidence tropo. Air in a highpressure system warms and dries; then, as it sinks (subsidence), it often traps cool moist air below it, forming an inversion.¹ That was the case in early September when dual high-pressure systems set up over the Midwest and Northeast on the 5^th and into the 6^th. See Figure 1.²

A number of QSOs in excess of 1,000 kilometers (621 miles) were made on 2 meters. On, Mike Cresap, W3IP, in FM19bb worked Jay Hainline, KA9CFD, in EN40om on 2 meters via FT8 @ 692 miles / 1,114 kilometers. Mike also worked K2DRH in EN41vr @ 663 miles / 1,069 kilometers. Gary Flynn, KE8FD, in EM64jv worked Stan Mattson, W8MIL, in EN74ic on 2 meter SSB @ 644 miles / 1,031 kilometers (Yes, there are still CW and SSB QSOs taking place on the bands!). Other notable QSOs reported include: WD9DBA, EN53ba, worked KF4WE, EM56nl, on 2-meter SSB @ 508 miles / 942 kilometers. KE8FD in EM64jv worked K8ZR in EN91iq via FT8 on 2 meters @ 568 miles / 914 kilometers; later the pair worked on 432 MHz SSB. KA9CFD in EN40om worked W3CP in EM74ug on 2 meters via FT8 @ 560 miles / 900 kilometers. AA9MY in EN50fm worked K4MY in EM74re on 2 meters via FT8 @ 516 miles / 830 kilometers. Matt Arthur, KAØPQW, located in EN33iu, worked KX4R, EM73lw, on 144, 222 (running only 10 watts!), and 432 MHz at just over 1,300 kilometers (~816 miles). Conditions continued again the next morning with Jay, KA9CFD, working John Stengrevics, WA1EAZ, on 2-meter FT8 just a few miles shy of the 1,000-mile / ~1,600-kilometer mark. See and for an indication of the extent of the opening.