Most Popular Articles
A Technical History of WHAV
Sign Off, Aug 2010
The other control room was similarly constructed, but its early equipment complement is not known. From this room, it was possible to look down into the announcer's booth as well as the smaller performance studio. An announcer's bathroom completes this level. It features the only window to the outside in this part of the building and became useful for announcers checking weather conditions outside.
Below, the first floor contained public restrooms, record storage areas, an announcers' lounge and the chief engineer's office and work area.
While the studio building was largely outfitted by Western Electric, the transmitter building a few miles away atop of Silver Hall was initially equipped by Raytheon. Raytheon operated a manufacturing facility (and still does) a few miles outside the city.
At the Silver Hill site, a three-legged self-supporting tower (later guyed) was erected. Its first 160' was designed for AM transmissions at 1490kHz, while an isolated 80' mast on the top was reserved for later FM transmissions. The transmitter building contains a large open area on the left for AM and FM transmitters and audio processing and monitoring equipment.
In the days before remote control and metering were allowed by the Federal Communications Commission (FCC), the right side of the transmitter building contained a bedroom and bathroom for the engineer on duty and a work area with benches.
The first AM transmitter was a Raytheon RA-250, 250W model. It was brown and tan in color and featured 12 external meters on two rows at the top of the cabinet. The transmitter used a 655 crystal oscillator, 807 buffer amplifier, 813 RF driver amplifier and two 810 tubes operating in push-pull as a power amplifier. This transmitter served as the main until at least 1960 and took on backup duty until the mid-1970s. I helped the engineer ready the unit for reuse on the amateur band in 1978 or 1979.
Two tall racks sit to the right of the transmitter with a ceiling-mounted, angled wooden box for a monitor speaker. A limiter, modulation monitor, frequency monitor, monitor amplifier and patch bays were installed in the racks, but their brand names have been lost to history.
WHAV-FM finally went on the air April 14, 1948. The station occupied 92.5MHz on the dial. Its first transmitter appeared to be a Western Electric 506B-1. It fed 10kW to the bays.
"FM broadcasting opens a new era for radio in Haverhill. It will give WHAV a second voice and will reach out into homes within a 50-mile radius of the city," The Haverhill Gazette announced.
-- continued on page 4
Acceptable Use Policy blog comments powered by Disqus
[an error occurred while processing this directive]
Today in Radio History
The history of radio broadcasting extends beyond the work of a few famous inventors.
Read each issue online in our Digital Edition Format in your Web browser.
EAS Information More on EAS
The feed provides feeds for all US states and territories.
Need a calendar for your computer desktop? Use one of ours.
Information from manufacturers and associations about industry news, products, technology and business announcements.
Browse Back Issues[an error occurred while processing this directive]
Also in the January Issue
- Trends in Technology: AES-X210, The "Missing Piece" of AES67?
- FCC Proposes Online Publc File Rules for Radio
- RF Engineering: Licensing AM Stations Using Method of Moments
- Field Report: Zoom H6