The Boston Radio Dial: WMBR(FM)

WMBR operates in stereo on 88.1 MHz from the top of the Eastgate student apartment building, with 720 watts ERP from 90 meters (295 feet) above average terrain. The custom four-bay Shively 6804DA-4 directional antenna has a gain of 5.01 dB; the transmitter is a Broadcast Electronics FM-250B. The analog studio-to-transmitter link consists of a half-mile of twisted-pair cable. The directional pattern protects a number of co-channel and adjacent-channel stations as well as the audio carrier of WLNE(TV) in New Bedford. The WGBH translator W242AA also broadcasts from this location.

Station History

WMBR traces its roots back to an MIT campus-only carrier-current AM station which called itself WMIT. It first signed on November 25, 1946, broadcasting from the basement of the Ware dormitory (now part of the Senior House dormitory) on 800 kHz (later 640 kHz). The station was entirely run and staffed by MIT students; even the equipment (including the transmitters) was built by electrical engineering students at MIT. Initially, the station only aired three evenings a week, programming classical and popular music, but programming eventually expanded across the week as more students joined the station's staff. Commercials were aired on the carrier-current station, which was soon able to support itself solely on advertising revenue.

In the mid-1950's, the station began exploring the possibility of obtaining an FCC licensed AM or FM commercial frequency in order to bring its programming to the fraternities located across the river in Boston, as well as faculty and staff located throughout the greater Boston area. It was soon discovered that the call letters WMIT were licensed to a station in North Carolina, so station management reluctantly chose WTBS (“Technology Broadcasting System”) as a second-best choice of call letters in 1956. It also turned out that all commercial frequency allocations in the Boston area at that time were taken, so the last available non-commercial FM frequency, 88.1 MHz, was chosen. The WTBS Foundation, Inc., was incorporated on March 10, 1959 as a corporation separate from (but related to) MIT which would hold the station's FCC license. New studio facilities were constructed in the basement of Walker Memorial, and the station moved to its new location in November of 1960. The station's technical staff constructed new equipment for the new studios, including the MK-60 console, believed to be one of the first all-transistorized radio consoles ever built. (Another larger all-transistorized board, the MK-62, joined the MK-60 a couple years later.) An FM transmitter and antenna were installed on the roof of the three-story Walker Memorial Building, sharing a tower with the MIT Radio Society (which still uses it today). Finally, on April 10, 1961, WTBS-FM signed on with a 10-watt monaural FM signal at 88.1 MHz.

The station's initial schedule consisted of two or three hours each weekday morning, then the station would sign off for the late morning and afternoon as the students attended class, followed by additional programming weekday evenings and on weekends. Community members were soon invited to the station, to help fill out the programming schedule, which filled in the afternoon gaps and eventually allowed the station to remain on the air during the summer and other vacation periods. Popular and classical music still dominated the schedule at first, but jazz and rock-n-roll programming was soon added, as well as other unusual features such as the “Waveform of the Week” (for the benefit of those MIT students who “watched” the station on oscilloscopes!).

WTBS-AM, the campus-only carrier-current station, still remained on the air, simulcasting the FM station's programming. Commercials still aired on the AM station, while the FM aired public service announcements. To break the monotony of the PSAs, station staffers produced a series of humorous “hack” commercials for fictitious products such as “Apple Gunkies”. With the superior quality and wider spread of the FM signal, fewer and fewer students listened to the AM frequency, advertiser support dried up, and the AM transmitters were finally turned off for good in 1974. The station turned to MIT for financial support in the form of an annual grant, which covered operating costs but did not provide funding for new equipment.

With the construction of high-rise skyscrapers in Boston and Cambridge during the 1960's (including MIT's own Green Building), the tower on the Walker Memorial roof soon proved to be inadequate. In 1971, WTBS received FCC approval to move its transitter and construct a new tower and antenna on the roof of MIT's 30-story Eastgate graduate student housing building near Kendall Square. WTBS then applied for an upgrade to a class A signal with 200 watts ERP in 1972. After numerous technical and legal hurdles, including the resolution of potential interference claims made by other FM and TV stations, the FCC finally granted WTBS a construction permit for 200 watts ERP from the existing Eastgate tower and antenna in 1978. However, the long battle was a costly one for WTBS, and the station no longer had enough money to buy a new transmitter. Help came from an unusual source: Ted Turner, who intended to distribute his TV station in Atlanta (then called WTCG) over satellite to cable operators across the US, wanted to use the call letters WTBS for his station, and contacted the MIT radio station with an offer to buy them. Since the purchase of call letters was not yet allowed by the FCC, Turner and the lawyers for both stations found a legal loophole made possible by the MIT station's recently-obtained non-profit organization status: $25,000 would be donated to the station by Turner under the condition that WTBS-FM would apply for and receive new call letters. Turner would then apply for WTBS, and would donate an additional $25,000 if the FCC granted him the call sign. The deal became reality: WTBS-FM became WMBR (“Walker Memorial Basement Radio”) on May 24, 1979, Ted Turner got the WTBS calls, WMBR received $50,000 from Turner, and WMBR signed on its new 200-watt signal on November 10, 1979. The station's licensee, the WTBS Foundation, Inc., changed its name to the Technology Broadcasting Corporation a short time later.

While the Turner money did allow WMBR to replace its transmitting equipment, the homemade 1960s-vintage studio equipment was beginning to show its age, and also prevented the station from upgrading to stereo until it could be replaced. In 1983, WMBR conducted its first large-scale over-the-air fundraising drive, which eventually became an annual one-week event. The money contributed from WMBR's generous listeners has allowed the station to completely overhaul its studio facilities; the original MK-60 and MK-62 consoles were retired in 1986 and 1989 respectively, replaced by modern stereo consoles. WMBR finally “flipped the switch” to stereo on May 13, 1987, and a minor upgrade to 360 watts ERP was granted by the FCC and completed by the station on March 2, 1989. An upgrade to 720 watts with the directional pattern described above was built on June 19-20, 1995.

WMBR's programming has greatly increased in diversity since it first signed on over the public airwaves over 30 years ago. Today, the station has over 70 different shows, ranging all across the musical spectrum as well as providing substantial public affairs programming. Its 200-person staff consists of MIT students, alumni, and staff, and community members from throughout the greater Boston area.

The Boston Radio Dial: WMBR(FM)

Who, What, Where

Technical Parameters

Station History

See Also