A communications receiver is a type of radio receiver used as a component of a radio communication link. This is in contrast to a broadcast receiver which is used to receive radio broadcasts. A communication receiver receives parts of the radio spectrum not used for broadcasting, including amateur, military, aircraft, marine, and other bands. They are often used with a radio transmitter as part of a two-way radio link for shortwave radio or amateur radio communication, although they are also used for shortwave listening.
The National HRO, a classic communications receiver c. 1936.
Commercial communications receivers are characterized by high stability and reliability of performance, and are generally adapted for remote control and monitoring. For marketing purposes, many hobby-type receivers are advertised as "communications receivers" although none are suited for heavy-duty, reliable 24-hour use as the primary form of communication for an isolated station.
Typically, a communications receiver is of the superheterodyne type in double, triple or, more rarely, quad conversion. It features multiple RF and IF amplification stages and may have at least one IF stage that is crystal controlled. It usually has a BFO and a product detector for SSB and CW reception. The frequency coverage of receivers of this type is typically in the range of 500 kHz to 30 MHz. Communication receivers are suited for operation near powerful transmitting facilities and so must have good internal shielding, and effective front-end filtering. They have design features to provide high selectivity and stability. Rejection of unwanted signals (images, intermodulation products) will typically be much greater than a consumer-type general coverage or broadcast receiver.
The front panel controls are typically more comprehensive than those on a broadcasting receiver. Usual features include: signal strength meter; RF gain control; AVC/AGC adjustments; band switching or preselector switching; selectable bandwidth filters or a Q multiplier; BFO tuning; and audio limiters or attenuators. Precise, calibrated, analog tuning and display dials are used, with a separate bandspread control to allow selective tuning of signals close in frequency. In more recent units, electronic digital frequency displays are provided. In communication receivers, the decorative wooden cabinets typical of early broadcast receivers were replaced with utilitarian metal cabinets to provide electromagnetic shielding and mechanical ruggedness.[1]
Communications receivers as an identifiable product type originated in 1933.[1] The older generation of tube-based communications receivers are affectionately known as boat anchors for their large size and weight. Such receivers include the Collins R-390 and R-390A, the RCA AR-88, the Racal RA-17L and the Marconi Electra. However, even modern solid-state receivers can be very large and heavy, such as the Plessey PR2250, the Redifon R551 or the Rohde & Schwarz EK070/D2-80.[2]
^ abJerome S. Berg, On the Short Waves, 1923-1945: Broadcast Listening in the Pioneer Days of Radio, McFarland, 2007; ISBN078643029X page 121
^Shortwave Receivers Past and Present: Communications Receivers, 1942-1997, by Fred Osterman. Published by Universal Radio Research, 1998. ISBN1-882123-07-7, ISBN978-1-882123-07-0
Further readingedit
Wikimedia Commons has media related to Communications receivers.
Osterman, Fred (1998). Shortwave Receivers Past & Present: Communications Receivers 1942-1997. Universal Radio Research, Reynoldsburg (USA).
Ulrich L. Rohde, Jerry Whitaker. Communications Receivers, Third Edition. McGraw Hill, New York, NY, 2001. ISBN0-07-136121-9.
January 01, 1970
communications, receiver, communications, receiver, type, radio, receiver, used, component, radio, communication, link, this, contrast, broadcast, receiver, which, used, receive, radio, broadcasts, communication, receiver, receives, parts, radio, spectrum, use. A communications receiver is a type of radio receiver used as a component of a radio communication link This is in contrast to a broadcast receiver which is used to receive radio broadcasts A communication receiver receives parts of the radio spectrum not used for broadcasting including amateur military aircraft marine and other bands They are often used with a radio transmitter as part of a two way radio link for shortwave radio or amateur radio communication although they are also used for shortwave listening The National HRO a classic communications receiver c 1936 Contents 1 Features 2 See also 3 References 4 Further readingFeatures edit nbsp RCA AR 88 Commercial communications receivers are characterized by high stability and reliability of performance and are generally adapted for remote control and monitoring For marketing purposes many hobby type receivers are advertised as communications receivers although none are suited for heavy duty reliable 24 hour use as the primary form of communication for an isolated station Typically a communications receiver is of the superheterodyne type in double triple or more rarely quad conversion It features multiple RF and IF amplification stages and may have at least one IF stage that is crystal controlled It usually has a BFO and a product detector for SSB and CW reception The frequency coverage of receivers of this type is typically in the range of 500 kHz to 30 MHz Communication receivers are suited for operation near powerful transmitting facilities and so must have good internal shielding and effective front end filtering They have design features to provide high selectivity and stability Rejection of unwanted signals images intermodulation products will typically be much greater than a consumer type general coverage or broadcast receiver The front panel controls are typically more comprehensive than those on a broadcasting receiver Usual features include signal strength meter RF gain control AVC AGC adjustments band switching or preselector switching selectable bandwidth filters or a Q multiplier BFO tuning and audio limiters or attenuators Precise calibrated analog tuning and display dials are used with a separate bandspread control to allow selective tuning of signals close in frequency In more recent units electronic digital frequency displays are provided In communication receivers the decorative wooden cabinets typical of early broadcast receivers were replaced with utilitarian metal cabinets to provide electromagnetic shielding and mechanical ruggedness 1 Communications receivers as an identifiable product type originated in 1933 1 The older generation of tube based communications receivers are affectionately known as boat anchors for their large size and weight Such receivers include the Collins R 390 and R 390A the RCA AR 88 the Racal RA 17L and the Marconi Electra However even modern solid state receivers can be very large and heavy such as the Plessey PR2250 the Redifon R551 or the Rohde amp Schwarz EK070 D2 80 2 See also editAmateur radio List of communications receivers Scanner Shortwave radio receiver Shortwave listening Shortwave radio Wadley LoopReferences edit a b Jerome S Berg On the Short Waves 1923 1945 Broadcast Listening in the Pioneer Days of Radio McFarland 2007 ISBN 078643029X page 121 Shortwave Receivers Past and Present Communications Receivers 1942 1997 by Fred Osterman Published by Universal Radio Research 1998 ISBN 1 882123 07 7 ISBN 978 1 882123 07 0Further reading edit nbsp Wikimedia Commons has media related to Communications receivers Osterman Fred 1998 Shortwave Receivers Past amp Present Communications Receivers 1942 1997 Universal Radio Research Reynoldsburg USA Ulrich L Rohde Jerry Whitaker Communications Receivers Third Edition McGraw Hill New York NY 2001 ISBN 0 07 136121 9 Retrieved from https en wikipedia org w index php title Communications receiver amp oldid 1154592077, wikipedia, wiki, book, books, library,
