The Hallicrafters SX-28 "Super Skyrider" is an American shortwave communications receiver that was produced between 1940 and 1946 that saw wide use by amateur radio, government and military services.
In July 1940, the Hallicrafters Company announced the SX-28 "Super Skyrider", the result of a development effort by 12 staff engineers and analysis of more than 600 reports that included input from U.S. government engineers, commercial users, and amateur radio operators. The SX-28's distinctive art deco styling was considered sleek and strikingly modern in 1940. The radio frequency coverage was 550 kHz (0.55 MHz) to 43 MHz in six bands. The SX-28 included an Amplified AVC, a Lamb Noise Silencer, Calibrated bandspread, and Push-Pull audio output. The SX-28 was known for its high fidelity audio together with high sensitivity, stability and selectivity, and good purchase value. [1] [2]
The SX-28 saw use by various branches of U.S. and allied military and intelligence agencies during World War II. SX-28 and Hallicrafters S-27 and S-36 receivers were often rack mounted in British government listening posts and secret listening stations for monitoring German radar and communications during the war such as Beaumanor Hall in the English Midlands where German and Italian encrypted radio messages were sent to Bletchley Park for decoding. [4] A number of the receivers were sent to the Soviet Union as a part of the Lend Lease Act, subsequently modified to accommodate Russian tubes. [5] [6]
Hallicrafters published that 50,000 SX-28 and SX-28A's had been built by the end of its production run in 1946, however the serial numbers appear to indicate a production figure of half, approximately 27,500 receivers. [7] Many of the SX-28/28A's that exist today are in the hands of vintage amateur radio collectors and amateur radio operators.
The name "Skyrider" was intended to bestow an aura of exotic adventure to Hallicrafters products and had a long history with the company. The first Hallicrafters set to be dubbed with the name was the 1932 S-1. [8]
Variations and special versions of the SX-28 were produced over the years. During World War II, Hallicrafters continued to redesign portions of the SX-28. [2]
Shortwave radio is radio transmission using radio frequencies in the shortwave bands (SW). There is no official definition of the band range, but it always includes all of the high frequency band (HF), which extends from 3 to 30 MHz ; above the medium frequency band (MF), to the bottom of the VHF band.
TV DX and FM DX is the active search for distant radio or television stations received during unusual atmospheric conditions. The term DX is an old telegraphic term meaning "long distance."
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Shortwave listening, or SWLing, is the hobby of listening to shortwave radio broadcasts located on frequencies between 1700 kHz and 30 MHz (30 000 kHz). Listeners range from casual users seeking international news and entertainment programming, to hobbyists immersed in the technical aspects of long-distance radio reception and sending and collecting official confirmations that document their reception of remote broadcasts (DXing). In some developing countries, shortwave listening enables remote communities to obtain regional programming traditionally provided by local medium wave AM broadcasters. In 2002, the number of households that were capable of shortwave listening was estimated to be in the hundreds of millions.
The 20-meter or 14-MHz amateur radio band is a portion of the shortwave radio spectrum, comprising frequencies stretching from 14.000 MHz to 14.350 MHz. The 20-meter band is widely considered among the best for long-distance communication (DXing), and is one of the most popular—and crowded—during contests. Several factors contribute to this, including the band's large size, the relatively small size of antennas tuned to it and its good potential for daytime DX operation even in unfavorable propagation conditions.
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DXing, taken from DX, the telegraphic shorthand for "distance" or "distant", is the hobby of receiving and identifying distant radio or television signals, or making two-way radio contact with distant stations in amateur radio, citizens band radio or other two-way radio communications. Many DXers also attempt to obtain written verifications of reception or contact, sometimes referred to as "QSLs" or "veries".
WNYW was a shortwave radio station that broadcast from Scituate, Massachusetts, in the United States. During WWII the station became important for the British and the Norwegian information services. On October 20, 1973, Family Stations, Inc., acquired the station to be part of its Family Radio network and changed the call letters to WYFR. Family Stations eventually progressively moved the transmitters to their current site in Okeechobee, Florida. The transmitter site in Scituate continued to operate until November 16, 1979, when it was switched off for the last time.
The National Radio Company, headquartered in Malden, Massachusetts, United States, was an American manufacturer of radio equipment from 1914 to 1991.
The original National HRO was a 9-tube HF (shortwave) general coverage communications receiver manufactured by the National Radio Company of Malden, Massachusetts, United States.
Vintage amateur radio is a subset of amateur radio hobby where enthusiasts collect, restore, preserve, build, and operate amateur radio equipment from bygone years, such as those using vacuum tube technology. Popular modes of operation include speaking over amplitude modulation (AM), and communicating using Morse code through continuous wave (CW) radiotelegraphy. Some enthusiasts have interest in owning, restoring and operating vintage military and commercial radio equipment such as those from 1940s to 1960s. Some undertake to construct their own gear, known in ham slang as homebrewing, using vintage parts and designs. A number of amateur radio clubs and organizations sponsor contests, events, and swap meets that cater to this specialized aspect of the hobby.
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The BC-348 is an American-made communications receiver, which was mass-produced during World War II for the U.S. Army Air Force. Under the joint Army-Navy nomenclature system, the receiver system became known as the AN/ARR-11.
The Hammarlund Super Pro was an American-made radio communications receiver.
The Hallicrafters SX-117 was a radio communications receiver manufactured by the Hallicrafters company in the 1960s.
The SCR-299 was a U.S. Signal Corps mobile military communications unit used during World War II.
The BC-342 was a World War II U.S. Army Signal Corps high frequency radio receiver. It was used primarily as part of field installations such as the SCR-188A, but could be used with mobile sets such as the 2 1/2 ton mounted SCR-399. First designed at Fort Monmouth, New Jersey by the U.S. Army Signal Corps, it was built by various manufacturers including RCA. Many of the later units that are encountered today were manufactured by the Farnsworth Television and Radio Corporation of Fort Wayne, Indiana. Variants include the low frequency coverage BC-344 receiver, and the battery or dynamotor powered BC-312 receiver.
A shortwave radio receiver is a radio receiver that can receive one or more shortwave bands, between 1.6 and 30 MHz. A shortwave radio receiver often receives other broadcast bands, such as FM radio, Longwave and Mediumwave. Shortwave radio receivers are often used by dedicated hobbyists called shortwave listeners.
In electronics, a Q multiplier is a circuit added to a radio receiver to improve its selectivity and sensitivity. It is a regenerative amplifier adjusted to provide positive feedback within the receiver. This has the effect of narrowing the receiver's bandwidth, as if the Q factor of its tuned circuits had been increased. The Q multiplier was a common accessory in shortwave receivers of the vacuum tube era as either a factory installation or an add-on device. In use, the Q multiplier had to be adjusted to a point just short of oscillation to provide maximum sensitivity and rejection of interfering signals.