The 'Inside-Out' Antenna Installation

How WTOP wound up with an unusual FM antenna configuration
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The WTOP(FM) antenna in 1952. View is from near the top of the tower looking down through the center. The ‘V’ radiating elements have been colored by RW for identification. The fourth set is partially obscured. The large vertical beam is the support mast.
Have you ever seen an FM transmitting antenna mounted inside its supporting tower?

It was not a case of installers misreading blueprints. The job was intentional and planned at every step.

The site was at the intersection of 40th and Brandywine Streets in downtown Washington; the time was the early 1950s. AM radio was still king, but many in the business were predicting a real future for FM and television. As a result, old-line owners were adding FM and television construction permits to their holdings and the FCC was eager to open up the new territory.

To set the stage, a brief history lesson involving some of Washington’s pioneer broadcasters is in order.

The catalyst was WTOP(AM). Though its roots can be traced to 1926 and Brooklyn, N.Y., for our purposes it’s only necessary to go back to the 1940s when WTOP was a 50 kW CBS O&O.

It was common for newspapers to be joined at the hip to broadcasting outlets; the Washington Post was no exception. Its broadcasting involvement started with ownership of a “local channel” AM outlet, WINX, which operated with 250 watts on 1340 kc. By the late 1940s, there was an FM outlet attached, WINX(FM), which had its start in 1939 as Washington’s first FM station, W3XO (experimental).

The station was nurtured by the radio consulting firm of Jansky & Bailey. W3XO took to the air on 43.2 megacycles in the original 42–50 mc FM band; by the time our story starts, it was operating with a commercial license on both 44.7 mc and 96.3 mc. This was the result of the FCC’s 1945 decision to “move FM ‘upstairs’ for its own good.” Low-band FMs were given three years to migrate, with 1948 being the official twilight time for low-band operations.

When the curtain came down on 44.7, WINX(FM) was on the air with a new “high-band” REL 10 kW transmitter and Western Electric type 54-A “four-section cloverleaf” antenna on Lee Highway in suburban Arlington, Va.

During this post-war period the Post was interested in expanding broadcasting operations and negotiated with CBS to purchase controlling interest in the WTOP(AM) O&O. The deal was consummated in February 1949, and a new company name appeared: WTOP Inc. As part of the deal, the Post’s 1340 kc peanut whistle had to be spun off.

This action also generated some interesting paperwork involving the Post’s FM.

Legal slight of hand

In an exhibit before the commission dated Jan. 11, 1949, the sale of WINX(AM) is described as part of the requirement for acquisition of the WTOP share from CBS.

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This drawing of the ‘inside out’ antenna installation was submitted by the station to the FCC. It was “subject to the condition that before the assignment is consummated The Washington Post Company has disposed of its interest in standard broadcast station WINX [the AM property] and its synchronous amplifiers, FM station WINX(FM) and developmental broadcast station W3XOT.” (AM radio “synchronous amplifiers” were akin to today’s “gap-filling” technology; they operated on-channel and were frequency synchronized with the main transmitter to provide additional service area.)

In additional paperwork filed on March 31, WTOP’s legal representative stated that “On March 23, 1949, the commission granted assignment of the license of FM broadcast station WINX(FM) from WINX Broadcasting to WTOP Inc. ... ‘subject to the condition that the assignment be not effected until WTOP Inc. has surrendered its conditional grant for station WTOP(FM)’.”

The communication went on to inform the FCC that the surrender took place on March 31 and that permission was being requested for WTOP Inc. to change the WINX(FM) call letters to WTOP(FM), effective the next day, April 1.

When the legalistic tap dancing ended, the Post wound up with its promised share of the formerly all-CBS WTOP(AM), and divested (on paper) itself of its WINX(FM) holdings. Yet it managed, again by paper maneuvering, to retain the 96.3 MHz FM outlet, which had been dubbed WTOP(FM).

Soon the Post/CBS partnership decided to expand its Washington broadcasting empire by adding television. After an unsuccessful effort to petition Channel 12 to the Washington area, it made an offer to the owners of an existing D.C. television station, WOIC, Channel 9. The acquisition was approved in 1950.

AM, FM and TV

Now the WTOP organization was as complete as possible in 1950, with AM, FM and television.

However, operations were spread out. The WTOP radio studios were in the Earle Building (now the Warner Building, home of the Warner Theatre) a few blocks from the White House. The 50 kW AM transmitter was in Wheaton, Md. and the former WINX(FM) operation was over in Arlington, Va.

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The WTOP(FM) construction permit details the unorthodox installation of the Andrew model 1304 four-bay antenna. The CP is dated Jan. 23, 1952. Note the provisional nature of the installation. To make things more interesting, the television transmitter for WOIC — now rechristened WTOP(TV) —was located at 40th and Brandywine in northwest Washington, along with a small origination facility.

Upper management decided to consolidate operations and in the process create something of a showplace. After all, this was the nation’s capital, home of statesmen and diplomats and an occasional stopping point for a celebrity or two.

The suburban Maryland AM three-stick directional transmitter plant couldn’t be relocated easily and was too remote from the city to serve as a base of operations. Ditto the Arlington FM transmitter location.

This left the TV transmitter site. It was on one of Washington’s several hills, some 410 feet above sea level overlooking downtown Washington and its suburbs.

Broadcast House

Plans were drawn up for a five-story building that would become Washington’s first purpose-built structure for radio and television broadcasting. To maximize space, the architect planned the building to fit around the existing self-supporting television tower.

Ground was broken for the combined facility, which would be known as Broadcast House, in late 1951. But after the initial excitement there was little joy.

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The WTOP(TV) tower/transmitter site at 40th and Brandywine as seen during initial construction of “Broadcast House,’ circa 1951–52. ©Broadcast News The site was on a small hillock and much excavation work was required to create the foundation for the planned 92,500 square foot building. Ordinarily, such site work is routine. Even in 1951, with the proper power equipment it could have been accomplished fairly quickly. This job was different.

At the root, literally, were the existing broad-based self-supporting tower and associated transmitter building. The staff worried that removal of too much dirt from the wrong place could cause the tower to topple.

“Excavation for the basement footings surrounding the existing tower was a tedious and frightening job,” recalled Clyde M. Hunt, then vice president of engineering at WTOP Inc. He was quoted in Broadcast News, a publication of RCA, in 1955.

“The wall of earth around the tower base was held together by hand-digging in alternate four-foot slits, each one being filled with reinforced concrete to prevent slippage of earth under the tower footings before another slit was dug.”

This was a squeaker, but Hunt reported that it was accomplished “without undue incident” and eventually work commenced on the new building.

The first technical build-out was in the space designated for the station’s garage. The idea was to create a temporary studio and control room to run technical operations until a permanent space was ready.

From our vantage point of more than 50 years later, it’s interesting to imagine what the production and engineering personnel must have been up against. This was a garage, not a sound-proofed and air-conditioned studio/control room complex. Construction noises, mud, occasional power outages and other unpleasantries had to be endured.

“It was a difficult year for management and staff,” Hunt told Broadcast News in what must have been a gross understatement. “Many temporary expedients were necessary for continuity of operations, requiring duplication of facilities and personal effort through many months.”

The FM moves in

This hectic activity was complicated by the decision — for reasons unknown, possibly economic — to relocate the FM transmitting operation from suburban Virginia to the 14th and Brandywine site while the building construction was underway.

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The completed five-story Broadcast House, in a photo probably taken late 1953. This appeared in RCA’s Broadcast News publication. A construction permit to allow the facility change was issued on Jan. 23, 1952. It provides an early sign of something out of the ordinary in its ���description of antenna system” section:

“Antenna supporting structure: 256-foot steel tower also used as antenna for TV station WTOP(TV) (FM antenna mounted inside tower, from about 26 feet below the top of the tower to about 72 feet below the top of the tower) Overall height above ground: 300 feet.”

A CP proviso that today reads like a cruel joke stated that the installation was “subject to submission of sufficient measurements made either during installation of the WTOP(FM) antenna or after installation is completed to indicate that the radiation characteristics of the antenna are not adversely affected by mounting within the WTOP(TV) antenna structure.”

Why inside?

Legendary Washington engineer Granville “Granny” Klink joined the WTOP operation in the 1930s, when the call was WJSV. I had the pleasure of meeting him on only one occasion before his death. He was in his 80s then, and still working for WTOP.

I’d heard rumors about the unconventional FM installation and made it a point to ask if these were true. “You know about that? I’d almost forgotten,” Klink replied.

He not only confirmed the story but supplied much information from memory about the details of the installation. He was particularly proud of the way it worked, telling me that the tower essentially was invisible to the top three antenna bays. The bottom-most bay couldn’t quite be positioned to “see” through the tower lattice as well as the others, but this proved not to be a serious impediment.

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The Broadcast House building today. The original 300-foot tower still stands, flanked by a taller mast installed in 1972. Broadcast use ceased in 1992. Photo by James O’Neal As for the reason behind the unorthodox antenna mounting, Klink said it was simply a case of “no room at the top.” The existing television antenna took up all available space there, and as the self-supporting tower had such broad faces, mounting of the FM elements on a side or even a corner would cause a large amount of coverage “shadowing.”

Remember that FM broadcasting at the time was a loss leader for most operations. It was hobbled severely by the FCC’s 1945 relocation of the FM broadcasting spectrum, which orphaned the nearly half million 42–50 MHz receivers sold to early FM adopters.

It’s easily imagined that the WTOP Inc. bean counters didn’t want to put any more money than absolutely necessary into the FM station and that this precluded multiple radiators on the tower sides. When the order was given to consolidate operations and move out of the Virginia location, Hunt, Klink and others probably did the best they could to please management.

I’ve found two published accounts of the “inside out” antenna project. The first includes Klink’s description of the way the antenna worked when “caged” by the tower. A 1952 article in Technician-Engineer magazine stated: “Granville Klink, chief engineer, compares the principle to that of looking through a plain glass window and then looking through a large mesh screen. You can still see the outside without difficulty.”

Three years later, Klink and M.W. Scheldorf, director of research at the Andrew Corp., which supplied the WTOP(FM) antenna, authored a short paper about the installation; it was published in Electronics magazine.

The story provided a technical overview of the unusual antenna installation and gave details about system performance. The authors stated that because the bay spacing was “slightly different than normal,” overall antenna gain was reduced by 0.3 dB.

Ogden Prestholdt, CBS corporate antenna engineer, was brought in from New York to perform admittance measurements on the system. These showed that, with the exception of the bottom bay, radiator performance was very close to what might be expected in free space conditions.

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Granville Klink, longtime Washington broadcast engineer. “The element in the bottom position is affected by the proximity of the tower by an increasing amount as the frequency is lowered,” Klink and Scheldorf summarized. “At the operating frequency, the admittance is changed by about 17 percent. Since only one bay out of the four is affected by the tower it is reasonable to expect that deviation from the free space pattern is probably less than 3 dB.”

Years later, Klink organized into scrapbooks a great amount of personal and engineering material that he had amassed. This included the Electronics magazine article. Klink included an undated note with it:

“The above article explains our thought processes on mounting the new Andrews [sic] Multi-Vee antenna in the top center of the existing WTOP(TV) antenna tower. The Multi-Vee had a gain of 2.3 which covered the Washington area very well. It turned out to be a wise decision and the antenna was in service until the Post gave the station to the Howard University ...”

End of an era

The unconventional antenna remained in service for some two decades.

In 1971, the Post donated WTOP(FM) to Washington’s Howard University, where it was renamed WHUR(FM). Studios were shifted to the school’s campus; the transmitter and antenna remained at Broadcast House for another year or so until a new 640-foot tower was constructed adjacent to Broadcast House, with both TV and FM transmitting operations being relocated there. The original antenna installation was kept as a backup facility for another 25 years.

Radio operations at 40th and Brandywine ceased in 1978 after WTOP(AM) was sold and relocated.

A Tour of Broadcast House Several months after moving into Broadcast House, the WTOP operation celebrated with a 30-minute live television tour of the new facility.


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This aired on Feb. 10, 1954, and was captured on kinescope (the videotape recorder was still more than two years into the future).

Not only does the video provide a thorough tour of the new broadcasting facility, it provides a priceless glimpse at what television (and radio) programming was like 50-plus years ago.

Content was overwhelmingly live, including musical acts, a daily children’s show and a how-to-cook program. Viewers should take note of the Spartan nature of the news set. On the radio side of things, disc recording was still viable, even though the station had installed new Ampex audio tape machines. The television operation went through a series of ownership and call letter changes — it’s now WUSA(TV) — and originated the last broadcast of any type at the Broadcast House facility in early 1992, relocating then to new quarters a few blocks away. The television transmitting equipment remained in Broadcast House until 1996.

The 1500 kHz WTOP(AM) operation no longer exists as such. The current station owner — Bonneville International, the Salt Lake City-based media group — acquired additional FM frequencies in the Washington area and moved the station’s all-news format exclusively to the FM band. Bonneville now uses the 1500 kHz 50 kW facility to air its Federal News Radio programming, using the call WFED.

The Broadcast House building was sold in 1996 and transmitting equipment was removed. However, visitors to the site still can see the original WOIC(TV) tower that was such an integral part of the structure that had to be “abandoned in place.”

The “inside-out” FM antenna elements are long gone, but if you look carefully, it may be possible to spot some of the mounting hardware used for the most unusual installation.

Curiously, in paperwork to the FCC, Andrew engineer Scheldorf stated that the concept of installing an antenna inside a tower structure “is not an original plan technically.” If readers are aware of other such installations, the author would be interested in hearing about them. Write to radioworld@nbmedia.com.

James O’Neal is technology editor for TV Technology and a frequent Radio World contributor. He thanks James Snyder and John Reiser for help in the preparation of this article.

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