VHF DXer and propagation expert Pat Dyer, WA5IYX, of San Antonio, Texas, has died. Licensed in 1963 and an ARRL member, he was 69.

“Pat contributed greatly to our understanding of sporadic E propagation, through both his professional research the Office of Telecommunications in Boulder, Colorado, and later through his personal observations,” Les Rayburn, N1LF, said in a post to the VHF Contesting reflector. Dyer’s research led to articles in both QEX and QST, and he delivered presentations at Central States VHF Society (CSVHFS) conferences. He also contributed to Ham Radio, Popular Electronics, CQ VHF, and CQ.

Dyer posted an extensive archive of propagation observations on YouTube. According to Rayburn, Dyer was a prominent TV and FM broadcast-band DXers and an active contributor to the Worldwide TV FM DX Association’s VHF/UHF Digest.

“Pat gave true meaning to one of the cornerstones of our hobby, which is to advance the state of the radio art,” Rayburn continued. “A citizen-scientist bar none, much of what we know about these mysteries would have remained hidden longer without his efforts.”