The history of Hallicrafters shortwave radio is a fascinating one. The company has released several models, including the SX-71, which was a 5 band communications receiver and mobile HF station. The S-120, a general coverage receiver, was also manufactured, and it had a voltage regulator for its critical oscillator voltage. These radios were designed to compete with the Hammarlund SP-600 Super-Pro.
SCR-299 was a mobile HF station
The SCR-299 was a mobile ham radio unit manufactured by the Hallicrafters Company during World War II. The production of this radio was backed by the company’s sponsorship of the Jam Handy Organization, which produced a documentary about the SCR-299 and its use by the Signal Corps. This film was made with the assistance of the US Army Signal Corps. It looks at the development of this radio, from its conception and construction to its use on battlefields in Europe and throughout the world.
The SCR-299 was a self-contained mobile high-frequency station that could operate from two to eight MHz and from one to 18 MHz. It was capable of transmitting a signal of 350 watts. It came in a K-51 truck and PE-95 trailer, and its power source was 115-volt, 60-cycle AC commercial power. The SCR-299’s power draw was 2000 watts, including a separate 1500 watts for lights and heater.
The SCR-299 was replaced by the SCR-399, a similar portable HF station. In addition to being vehicle mountable, the SCR-399 power unit was also a K-52 trailer. In the US Air Force, the SCR-499 was developed specifically for air transport and soon became the standard. The Hallicrafters SCR-299 is an important piece of Amateur radio history.
SX-71 is a 5 band communications receiver
The SX-71 is a 5-band communications receiver. It covers AM broadcast frequencies between 538 KHz and 34 MHz, shortwave frequencies from 46 to 56 MHz, and the 10 and 15 meter ham bands. The SX-71 is missing the push-on round metal “H” symbol on the bandspread dial. It does have a crystal filter, however.
The Hallicrafters SX-71 is an AC-operated, 14-tube shortwave receiver. It covers frequencies from 538 KHz to 35,000 kc. It can also pick up narrow-band FM and AM signals. The SX-71 produces up to 3 watts of audio output and works with Hallicrafters R-44B and R-46 speakers.
The SX-71 is the most popular Hallicrafters communications receiver. It has a hefty central dial, which is easy to read. Its sound quality is superior to many expensive home receivers. The SX-71 was a popular collector’s item. It was also a full mobile HF station. Its price is about $1700. You can purchase a Hallicrafters SX-71 today for a fraction of what it cost in its day.
S-120 is a general coverage receiver
The Hallicrafters S-120 is based on the popular S-38 receiver line and was marketed as a single-conversion superheterodyne receiver that covers the entire range of AM and CW bands. Its circuit utilizes four tubes and a selenium rectifier to provide continuous coverage from 540 KHz to 31 MHz. The S-120’s frequency range is wide, so it can be used for a variety of situations.
The Hallicrafters S-120 has a missing back panel and two connections on the rear apron. The leftmost connection is the power cord, while the rightmost connection is the external antenna. On the rear apron, there is also a sticker with the serial number. The orange wire from the ferrite rod antenna does not make electrical contact with the screw connection for external antenna.
The S-120 is a popular shortwave radio in Japan and America. The S-120’s circuit has 9 transistors and covers frequencies from 1.6 to 4.4 MHz. This receiver also has a main tuning dial and is made in Japan. This model has a very similar design to the S-125 and S-120A. It is easy to operate but does not compare well with the SX-115 or SX-122.
Another important feature of the S-120 is its solid-state construction. Unlike the S-38, the S-120 is solid-state. The S-120 was introduced in 1961, and is an updated version of the S-38. The S-120 is still a general coverage receiver that uses 4 tubes. The S-120A has an upgraded solid state version. It is an excellent option for beginners and older amateurs alike.
S-120 has a voltage regulator for the critical oscillator voltage
The Hallicrafters S-120 has regenerated the critical oscillator voltage with a voltage regulator. The circuitry is simple and easy to understand, with a back panel that is missing, and two connections on the rear apron. One connection is for the external antenna, and the other is for the power cord. The power cord is located to the right of the external antenna connection, and has a sticker that lists the model number. Another connection is for the power cord, which is located on the rear apron, and is to the right of the external antenna connection. It is worth noting that the orange wire that connects to the ferrite rod antenna does not make electrical contact with the screw connection.
The Hallicrafters S-120 uses 4 tubes. One is a 12BE6 as the oscillator, while the other is a 6J5 or 6C4. A power supply transformer is required to run the S-120, but this is a rare option. Underwriters Laboratories would never allow this type of radio to be soldered on to a product.
The S-120’s operator controls occupy the bottom portion of the front panel. These controls include a bandpread tuning knob, an On/Off switch, and a 1/4-inch headphone jack that automatically disconnects the internal speaker when used. Another control is the BFO, which is used to provide a beat frequency tone when receiving CW. The BFO also serves as a sensitivity adjustment.
S-38 is a transformerless AC/DC radio with an integrated speaker
The Hallicrafters S-38 is essentially the same as the earlier S-38A, with slight differences in color finishes, back panel changes, and the power cord attachment. The C model used a 12SG7 tube for the IF amplifier. The A, B, and D models had smooth black finishes while the E and EM had mahogany-colored finishes.
The S-38 is an example of a rare model of the radio. It is a transformerless AC/DC radio with an integrated speaker that was manufactured until the early 1960s. The S-38 features a metal cabinet, a built-in speaker, and separate bandspread tuner. The S-38 also has a noise limiter, automatic noise-limiter, and beat frequency oscillator, which makes it a popular hot radio today.
The S-38A incorporates a superheterodyne receiver for receiving AM and CW signals. Its AF output is controlled by a volume knob, and it hisses when there is no signal. Once you’ve tuned onto a signal, the radio’s sensitivity is adjusted with a volume knob. The AF output quiets down when you’re far away, when the station stops transmitting, or when it’s on a frequency other than the one you’re listening to.
The S38 series was popular among consumers in the 1940s. Its line cord was insulated by a rubber washer that was permanently attached to the chassis. This made it prone to electrocution. The S38D had a high degree of selectivity in AM broadcast testing, and the RF output was highly selective. The S38D was also sensitive in the AM broadcast testing. The S38D radio also features a 0 to 100 logscale bandspread, which offsets the tuned frequency by a few kilocycles. Finally, the S38D had a switch for standby mode, which powered the IF amplifier.