Short Wave listening
What is short wave listening?
Shortwave listening, also known as SWLing, is the hobby of listening to shortwave radio broadcasts from around the world. Shortwave radio is a type of radio communication that uses the upper MF (medium frequency) and all of the HF (high frequency) portion of the radio spectrum.
This allows shortwave radio signals to be transmitted over long distances, and enables people to listen to international broadcasts from faraway countries. Many people enjoy shortwave listening as a way to learn about different cultures and to keep up with world events. It is also a way to make connections with people in other countries and to learn about different languages and customs.
What equipment do I need?
To get started with shortwave listening, you will need a shortwave radio and an antenna. There are many different types of shortwave radios available, ranging from portable handheld models to more expensive, feature-rich tabletop units such as dedicated receivers and SDR receivers. When choosing a shortwave radio, consider the features that are important to you, such as the number of bands and frequencies it can receive, the size and portability of the unit, and any additional features such as a digital display or built-in clock.
In addition to a shortwave radio, you will also need an antenna to pick up the shortwave signals. The type of antenna you need will depend on the location of the radio and your listening preferences.
A simple wire antenna, such as a random wire or long wire antenna, can be a good choice for someone just starting out with shortwave listening. These antennas are easy to set up and can be used indoors or outdoors. For more advanced listening, you may want to consider a directional antenna, such as a beam antenna or a loop antenna, which can help you to more accurately tune in to specific stations.
Other equipment that can be helpful for shortwave listening includes a good pair of headphones to help you hear the signals clearly, a notepad and pen to take notes on the broadcasts you hear, and a frequency guide or shortwave listening schedule to help you find stations to listen to.
What is DX?
In shortwave listening, "DX" refers to distance listening or long-distance listening. It refers to the act of listening to shortwave radio stations that are located far away from your current location.
DXing can be more challenging than listening to local stations, as the signals are often weaker and may be prone to interference. It is important to have a good quality shortwave radio and antenna to help improve reception, and it can be helpful to have a frequency guide or shortwave listening schedule to help you find stations to listen to. Many shortwave listeners enjoy the challenge of trying to hear as many different stations as possible from around the world, and some even keep a log of the stations they have heard in order to track their progress.
What is RFI
RFI stands for radio frequency interference. It is a type of electrical interference that can cause problems with the reception of radio signals, including shortwave signals. RFI can be caused by a variety of sources, such as electrical appliances, power lines, and other electronic devices. It can also be caused by natural sources, such as lightning or solar flares.
RFI can affect shortwave listening in a number of ways. It can cause static or noise in the signal, making it difficult to hear the audio clearly. It can also cause the signal to fade in and out, or to be completely blocked. In severe cases, RFI can make it impossible to receive a signal at all.
There are several things that you can do to help reduce the effects of RFI on your shortwave listening experience. One of the most effective ways to reduce RFI is to use a good quality, high-gain antenna, which can help to filter out some of the interference. It can also be helpful to use a radio with good selectivity and sensitivity, as this can help to improve the signal-to-noise ratio and make it easier to hear the audio clearly.
In addition, you can try moving the radio or the antenna to a different location, as this can sometimes help to reduce the amount of interference you are experiencing. Finally, you can try using filters or other types of RF shielding to help block out the interference.
What is RFI
A type of electrical interference that can affect the performance of radio equipment, including shortwave radios. It occurs when an interfering signal enters a system in the same phase on both the positive and negative sides of a circuit. This can cause the interfering signal to cancel itself out when it is processed by the radio, resulting in poor reception or no reception at all.
What does a Common Mode Choke do?
A common mode choke is a type of filter that is used to reduce common mode interference in radio equipment, including shortwave radios.
It works by blocking common mode signals from entering the circuit, while allowing differential mode signals to pass through.
A common mode choke consists of a coil of wire that is wound around a ferrite core. The coil acts as an inductor, which has a higher impedance to common mode signals than it does to differential mode signals. As a result, common mode signals are effectively blocked from passing through the choke, while differential mode signals are allowed to pass through with minimal loss.
Common mode chokes are often used in conjunction with other types of filters, such as low pass filters or high pass filters, to help improve the performance of radio equipment. They are especially useful in situations where common mode interference is causing problems with the reception of shortwave signals, as they can help to reduce the amount of interference and improve the signal-to-noise ratio.
Common mode chokes can be purchased as standalone components or as part of a filter assembly, and they are relatively simple to install in most radio systems.