What’s better than one passive reflector tower? How about two?
Passive reflector towers — also known as “periscope” or “flyswatter” towers — are an interesting piece of microwave transmission history. Instead of having waveguide ran up the tower to an antenna mounted at the top, they transmitted from an antenna mounted at the tower base (sometimes on top of the base station). The antenna was directed upward, and the passive reflector — mounted at a 45-degree angle at the top of the tower — reflected the beam outward to the next site.
While common in the middle of the 20th century, they are a rarity today. The design was eventually outlawed due to stray radiation that continued into space, causing potential interference with satellites.
I traversed north to Roanoke to photograph one such tower. However, I actually found another “flyswatter” tower on my way to the intended destination.
Central Electric Power Cooperative: KEU50
Approximately three miles east of Roanoke, Missouri, on Route B is a 323-foot guyed mast with a periscope design. Located adjacent to a power substation, the site is used by an electric cooperative. The ASR for this site is 1003950. The site is also known as the Yates site, named for another nearby unincorporated community.
This was my intended destination — as the Long-Lines.com map identified this as the Roanoke AT&T Long Lines site. However, as I’ll discuss later, this is NOT the AT&T site.
However, my photos of this site provide a good example of how a periscope tower operated. You can see the antenna, mounted upward near the base station, and the passive reflector at the top.
Southwestern Bell Telephone: KPP59
On my way to the “Yates” tower owned by Central Electric Power Cooperative, I passed another passive reflector/periscope tower. As I’d eventually learn from a viewer’s email, this was the site I was looking for.
This site wasn’t an AT&T Long Lines site, but was instead of a Southwestern Bell Telephone short-haul site. It had a southwestern hop to the Slater AT&T Long Lines site, and a northeastern hop to the central office in Moberly.
There were a couple things that made me question whether the Yates CEPC site was the one I was looking for. For starters, it only had one antenna — aimed southwest. There were no antennas aimed northeast for the Moberly hop. Furthermore, the KS-15676 horn-reflector antenna at Slater aimed toward Roanoke was on a low outrigger platform (on a relatively short tower to begin with). It would not align with the 323-foot Yates tower.
However, the Southwestern Bell Telephone guyed mast is far shorter — and has two passive reflectors. One passive reflector is positioned southwest for the Slater hop, and another northeast for the Moberly hop.
The viewer’s email had deeds that showed the site was in fact the Southwestern Bell site I was looking for. He added its call sign was KPP59. Because it was a RBOC site, its call sign was not listed in the 1974 AT&T call sign index.
The Roanoke SWBT site changed hands in February 1992, indicating the microwave link was turned down sometime in the late 1980s or very early 1990s.
Edited 4-26-2025 to include maps