SCR-197

The SCR-197 was a ground mobile high frequency radio station used by the United States military prior to and during World War II, notably during the Battle of Wake Island in 1941.

Specifications

The SCR-197 mobile station consisted of the BC-325 radio transmitter with a frequency coverage of 1.5 to 18 Mhz and an RF power output of 400 watts. Radio receivers consisted of three BC-342 and one Hallicrafters S-20R "Sky Champion". Also provisioned was a BC-119 control box. The complete set was housed in a K-18 truck and K-19 trailer combination. A 45 foot vertical antenna was used for sending and a 15 foot whip used for receiving. Power could be optionally supplied by power mains or portable generator units: one PTO driven GN-42-A generator for the transmitter and two small PE-75 skid mounted units for the receivers. The SCR-197 set was later replaced by the SCR-299.

See also

90.3 ABC Coast FM

90.3 and 95.3 ABC Coast FM is an ABC Local Radio station based in Maroochydore. The station broadcasts to the Sunshine Coast region of Queensland. This includes the towns of Nambour, Caloundra, Noosa and Gympie.

It was originally set-up to target the youth market and broadcast to the Sunshine Coast from a studio at 612 ABC Brisbane. The station is now a news, current affairs and adult contemporary music station.

Like most other ABC Local Radio stations throughout regional Queensland, ABC Sunshine Coast offers local breakfast and morning programs between 5am and 11am with an additional local drive program between 3pm and 6pm. All other programming originates from metropolitan ABC stations, such as the early afternoon and evenings programs which are broadcast from 612 ABC Brisbane.

In late September 2014, to fall in line with most ABC Local Radio stations in Queensland, ABC Sunshine Coast began broadcasting their own local edition of The Rural Report, broadcast at 6:20am during the local breakfast program, presented by a Sunshine Coast-based rural reporter. Upon the launch of the local Rural Report, ABC Sunshine Coast also began taking statewide rural affairs program, The Queensland Country Hour, between midday and 1pm.

Survival radio

Survival radios are carried by ships and aircraft to facilitate rescue in an emergency. They are generally designed to transmit on international distress frequencies. Maritime systems have been standardized under the Global Maritime Distress Safety System.

History

The use of radio to aid in rescuing survivors of accidents at sea came to the forefront after the sinking of the RMS Titanic in 1912. Lifeboats were equipped with spark gap transmitters such as the Marconi Type 241, c. 1920. These operated using Morse code on 500 kHz, the international distress frequency at the time. This frequency had the advantage of long range due to ground-wave propagation and was constantly monitored by all large ships at sea after the Titanic's sinking. However, due to its wavelength of 600 meters, a long antenna was required to achieve good range. Long wires on the order of 1/4 wavelength held up by kites or balloons were often used. Spark-gap continued to be used in lifeboats long after the technology was banned for general communication.

SCR-68

The SCR-68 (SCR was a military term meaning Set, Complete, Radio) was a military radiotelephone used by the US Army Signal Corps as an aircraft radio in the waning months of World War I. Due to its many problems, primarily its inability to communicate with other radios, like its ground component the SCR-67 or the larger truck mounted SCR-108, over large distances, the SCR-68 quickly became obsolete. Nonetheless, the SCR-68 was one of the first steps towards developing more effective messaging between pilots and commanders, even beyond military usage.

Capabilities

The SCR-68 had a few distinct characteristics that separated the SCR-68 from other types of radio. The SCR-68 operated at 750 kHz (400 meter wavelength), using a long wire antenna reeled out behind the aircraft. It could receive and transmit messages over a maximum range of eighteen miles. The artillery observer (navigator) managed the SCR-68, receiving and relaying messages for the pilot. During World War I, most planes were two-person open-cockpit aircraft. Instead of communicating between themselves in the air, the pilot and the observer sent messages through the SCR-68 where the headphones would eliminate most outside noises. Like a private telephone line, the pilot and observer could communicate with each other; however, this action prevented the SCR-68 from receiving any transmissions.