Short Wave Radio Receivers

Shortwave radios are desired among hobbyists because no license is required for the operation of a shortwave receiver in the United States or Canada. Amateur radio licenses are granted through government agencies for non-commercial communications. Shortwave radio transmitters and receivers are often used for this purpose.

Individuals, who desire a shortwave radio hobby or other forms of short wave listening, will quickly realize that the world of shortwave radio consists of a variety of manufacturers and models. The radios vary by size and features primarily. A shortwave radio can be tailored to the individuals listening interests.

Individuals who are accustomed to newer technologies find it difficult to listen to shortwave radio. Interference with appliances, television and computers are often a problem with shortwave radio. However, the technology can be a life saver during a storm or war time. Shortwave radios are most often used in less affluent countries because of its accessibility and affordability. Western countries only employ the use shortwave for hobbyists and enthusiasts. Shortwave is often also used in military or maritime situations.

A shortwave radio is desirable because it is affordable. When other radios do not work, a short wave radio will work in countries with limited resources. Shortwave radio frequencies travel farther than FM radio stations typically travel. Shortwave radio cost very little to broadcast across a large area.

There are several types of receivers available to the consumer. Several are listed below:

•  Crystal Radio Receivers: These simple receivers operate by using the power received from radio waves.

 

• Scanners: These types of receivers can automatically scan for a particular frequency. Scanners are often used for monitoring VHF and UHF radio systems.

 

•  Audio Receivers: Audio receivers are used by a typical ordinary user in order to receive radio frequencies at home.

Digital signal processing (DSP) is often used in modern shortwave receivers to digitize the analog signal and transmit a more crisp sound to the audience. Digital signal processing is primarily used in shortwave, however, to customize the bandwidth of the receiver to deliver a signal congruent with the current reception conditions. A DSP receiver can achieve 40 or more different bandwidths or filters, but an analog receiver can only achieve a small number of bandwidths by comparison.

Shortwave radios have progressed to “software defined radios” as well. Each aspect of the signal is manipulated via software. The filtering and frequency modulation each are manipulated via software before transmitting to the listening audience. Most of this type of manipulation will occur on a PC sound card that contains a digital signal processor (DSP). This type of technology allows users to switch between higher end technology such as HDTV broadcast to an AM broadcast seamlessly and within an instant. DSP technology may also allow for radio programming to be recorded for future playback. Though a simple technology, shortwave radio has integrated some modern features that allow enthusiasts to enjoy modern conveniences with the advantages of shortwave radio.

A radio is a device that sends and receives radio waves, which are waves from a specific part of the electromagnetic spectrum. Radio signals are further categorized into shortwave and long-wave signals. Since the frequency of a wave is measure by the distance between each wave, shortwave radio signals have a much higher frequency than long-wave signals.

It is also important to remember that frequency is also linked with power; therefore the higher the frequency, the greater the power of the signal. When this is applied to shortwave and long-wave signals, shortwave has a definite advantage over long-wave in terms of distance. Shortwave signals can be sent thousands of miles in any direction while using less power than long-wave signals.

Shortwave radios began taking the world by storm in the 1920s as an extremely disruptive technology. They began eliminating the need for transatlantic telegraph cables. Today, shortwave technology is losing ground to computer-based technologies such as the Internet and satellite radio.

A shortwave radio is actually a modified AM radio. Since AM radio signals are transmitted in both shortwave and long-wave frequencies, but long-wave radios do not pick up shortwave signals, it is necessary to have a modified AM radio in order to pick up shortwave signals.

All radios receive signals by means of electromagnetic transduction. Since radios are electromagnetic waves below the frequency of visible light, all a transmitter has to do is modify the basic signal in some way in order to send information. This is usually done by changing the frequency or the amplitude of the signal. Radio waves are detected and turned into sound when they pass through an electrical conductor. The electromagnetic waves induce a current in the conductor coil, which is then turned into sound waves by electrical circuitry.

Early radios had to rely completely on the energy of the broadcast in order to power the conductor. This is one of the reasons why shortwave radios became so popular: they could pick up and send signals of much higher power, thus enabling them to rely completely on the broadcast’s electrical power to turn the signals into audio.

Shortwave radios today contain digital equipment that can tune high-frequency circuitry to an incredible array of signals available for reception. Shortwave technology is still widely used by amateur radio enthusiasts because of the ease of receiving and sending signals.

Inside a shortwave radio, the high-frequency circuitry is used to modify the operation of the coiled wire inside the electrical conductor. The downside to shortwave signals is that receivers have to be especially sensitive in order to pick them up due to their high frequency. Shortwave radios pick these signals up by using the conductor to sense even slight changes in electromagnetic waves.

Taped in Sydney in 1990. I had no idea what this was at the time. Well I have come to the conclusion since I posted this vid, that this is a Numbers Station. Thanks for all the help guys! I never though that I would find out what the hell it is. Thanks Again.

Radio Receiver: Etón G3 Globe Traveler Location: Craiova, Romania Time: 15:00 UTC 2011-01-03 Station: Sudan Radio Service Language: Arabic Frequencies: 17745 KHz (Sines, Portugal 2781 Km) i.imgur.com Info: www.sudanradio.org

Receiving the world’s most distant shortwave stations (at least from my location in Germany) with my Sony ICF-SW7600GR portable world band receiver and its built-in telescopic antenna: Radio Australia on 9475 kHz from Shepparton (16140 km/9770 miles) Radio New Zealand on 5950 kHz from Rangitaiki (18202 km/11018 miles) Reception was on 2 February 2011 at 1500 UTC and 1505 UTC. Radio Australia had massive coverage of the cyclone “Yasi” and relayed programming of ABC Local Radio Queensland. Radio New Zealand International relayed a weather forecast and further programming from their domestic service as well.

Turned your normal home short wave radio receiver into SSB mode HAM band receiver. Tune the 1st radio(Sony in this video) to 7Mhz(40m ham band) and fine tune until you hear scratching QSO(suppressed carrier) over the HAM band. Switched on the 2nd radio(Panasonic radio cassette in this video), low down the volume as you don’t need to hear it, tune smoothly to 7Mhz until you hear whistling sound over the 1st radio. Fine tune carefully until you hear actual SSB. QSO over the 1st receiver. Actually you beat(injecting missing carrier) to the 1st radio receiver using the 2nd radio IF oscillator or we call it BFO. Try to practice until you use to tune either USB of LSB( a little bit up or down) using the 2nd receiver. Good luck. 9M6XDD, Borneo.

Realistic SX-190 shortwave radio was given to me and works well.