The Collins 207B-1 was a radio transmitter manufactured in 1951 by Collins Radio Company.

Specifications

The 207B-1 was capable of 35 kilowatts of RF

Radio frequency

Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...

 output in amplitude modulation

Amplitude modulation

Amplitude modulation is a technique used in electronic communication, most commonly for transmitting information via a radio carrier wave. AM works by varying the strength of the transmitted signal in relation to the information being sent...

 mode, and 50 kilowatts in continuous wave

Continuous wave

A continuous wave or continuous waveform is an electromagnetic wave of constant amplitude and frequency; and in mathematical analysis, of infinite duration. Continuous wave is also the name given to an early method of radio transmission, in which a carrier wave is switched on and off...

 mode. The transmitter was designed for land-based operation within the frequencies of 4 to 26 MHz and was contained within five sheet metal cabinets bolted together to form a single unit with a weight of 16,800 pounds. Intended primarily for high speed telegraphy

Telegraphy

Telegraphy is the long-distance transmission of messages via some form of signalling technology. Telegraphy requires messages to be converted to a code which is known to both sender and receiver...

 and broadcasting

Broadcasting

Broadcasting is the distribution of audio and video content to a dispersed audience via any audio visual medium. Receiving parties may include the general public or a relatively large subset of thereof...

, the 207B-1 was capable of high power AM transmission and telegraphic or frequency-shift keying

Frequency-shift keying

Frequency-shift keying is a frequency modulation scheme in which digital information is transmitted through discrete frequency changes of a carrier wave. The simplest FSK is binary FSK . BFSK uses a pair of discrete frequencies to transmit binary information. With this scheme, the "1" is called...

 at speeds greater than 400 words per minute. It could also be used to amplify the power output of a single-sideband modulation

Single-sideband modulation

Single-sideband modulation or Single-sideband suppressed-carrier is a refinement of amplitude modulation that more efficiently uses electrical power and bandwidth....

 transmitter to a peak envelope power

Peak envelope power

Peak envelope power is the average power supplied to the antenna transmission line by a transmitter during one radio frequency cycle at the crest of the modulation envelope, under normal operating conditions. The United States Federal Communications Commission uses PEP to set maximum power...

 of 30 kilowatts.

Usage

In April of 1951 the United States Coast Guard Cutter

United States Coast Guard Cutter

Cutter is the term used by the United States Coast Guard for its commissioned vessels. A Cutter is or greater in length, has a permanently assigned crew, and has accommodations for the crew to live aboard...

 USCGC Courier was equipped with two 207B-1 transmitters during its time as a ship-borne radio relay station to transmit Voice of America

Voice of America

Voice of America is the official external broadcast institution of the United States federal government. It is one of five civilian U.S. international broadcasters working under the umbrella of the Broadcasting Board of Governors . VOA provides a wide range of programming for broadcast on radio...

 programs behind the Iron Curtain

Iron Curtain

The concept of the Iron Curtain symbolized the ideological fighting and physical boundary dividing Europe into two separate areas from the end of World War II in 1945 until the end of the Cold War in 1989...

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