Two California radio amateurs — one of them in Hawaii — have set new world distance records on the 2.3 and 3.4 GHz microwave amateur bands. Wayne Overbeck, N6NB, operating from a radio-equipped rental car on the big island of Hawaii, worked Gregory Campbell, W6IT, operating Overbeck’s own fixed station near Orange, California, on both bands — a distance of more than 4024 km (2495 miles). The contacts blew away records that had stood for more than 20 years and more than doubled the previous distance record for a two-way voice (SSB) contact at those frequencies, Overbeck said, adding that most previous microwave distance records have been set using CW.

“These are the first-ever SSB contacts between Hawaii and the mainland on 2304 and 3456,” Overbeck said.

The record-setting contacts occurred on June 19 (June 18 in Hawaii) on 2.3 GHz at 0257 UTC and at on 3.4 GHz at 0300 UTC. W6IT was in grid square DM13cs, while N6NB/KH6 was in BK29hq. According to the database of distance records maintained by Al Ward, W5LUA, the old record was 3982 km, set on by KH6HME (SK) and N6CA on July 14, 1994, on 2.3 GHz and on July 28, 1991, on 3.4 GHz. Both contacts were on CW.

Overbeck flew to Hawaii carrying gear for all bands from 144 MHz through 10 GHz “in two large suitcases, plus a roll-aboard and a backpack” — weighing about 150 pounds in all. In Hawaii, he rented a small SUV and built a rover-style station that included a rotating roof platform constructed using parts obtained from a home improvement store.

Overbeck said that when a tropospheric duct formed that could convey signals thousands of miles across the Pacific, he drove around the slopes of Mauna Loa — 13,000 feet up —and selected several promising sites for long-haul DX, “not necessarily the highest possible sites,” he added. “By Thursday, June 18, the duct seemed to be peaking,” he said.

W6IT activated N6NB’s fixed station and quickly worked N6NB/KH6 on six bands, including 2304 and 3456 MHz for world records. Overbeck said he also heard W6IT on 902 MHz and 5.7 GHz, but local, non-amateur interference in California — likely from Part 15 WiFi devices — prevented W6IT from hearing N6NB/KH6 on those bands.

A video of the record-setting 2304 GHz contact between N6NB/KH6 and W6IT (recorded from the Hawaii end of the circuit) is online.