The Frequency-Hopping Spread Spectrum (FHSS) is a means of transmitting radio signals by shifting a carrier across a number of channels with a pseudorandom sequence that the sending and receiving station knows beforehand. The method is used as a multiple access process in the FH-CDMA (Frequency Hopping Code Division Multiple Access) transmission scheme. What Are the Advantages of Spread-Spectrum Transmission? The frequency hopping spread spectrum over a fixed-frequency transmission method has 3 primary advantages: #1 – The method is very resistant to narrow band interference since the spread signal causes Read More

CB (Citizens Band) Radio is an unlicensed service. CB Radio consists of 40 HF channels on AM and SSB. Channel 9 is designated for emergencies and assistance. The maximum allowable power for a CB radio is 5 watts. Repeaters are not allowed on CB radio. CB Radio Usage CB Radio is mainly utilized by truck drivers. CB radio is known for the colorful language utilized by its adherents, such as "10-4 good buddy". CB Radio Frequencies Channel Frequency 1 26.965 2 26.975 3 26.985 4 27.005 5 27.015 6 27.025 Read More

UHF is an acronym for a band of radio frequencies often used to broadcast television signals. Mobile phones and satellite radio also use UHF signals. The letters ‘UHF’ stand for: Ultra High Frequency. UHF Frequencies Any radio frequency between 300 MegaHertz (MHz) and 3,000 MHz (or 3 GigaHertz) is considered to be in the UHF signal range. This range is less commonly known as the decimeter range. Frequencies immediately below 300 MHz are part of the VHF range. Radio frequencies above 3,000 MHz are categorized into the Super High Frequency Read More

Standing Wave Ratio (SWR) meters are used to measure the standing wave ratio in a communications transmission line. The meter can display how much a transmission line and the load are mismatched (normally a radio antenna). It also determines how effective the impedance is of matching efforts. In CB and ham radio circles, the SWR meter is used to help determine how much RF energy is being reflected back to the transmitter compared to how much is being sent out during operation. If the amount of reflected radiation is too Read More

XM Radio is a satellite radio service. Satellite radio is a technology that for the most part has been around for many years. For instance, many television studios have been using satellites to beam TV signals from far away locations to viewers for decades, however satellite radio has been in operation in America since 2001. Satellite radio is pretty easy to describe. The programs for satellite radio include music, talk shows, live sporting events and sport analysis shows. These shows are usually sent from one central location, where they are Read More

Coax connectors are essentially any connectors that are used to connect a coaxial cable to another cable or a device that requires a signal carried by the coaxial cable. They come in a variety of shapes and sizes and can be known by quite a few names. Among these, the most common alternative name for coax connectors are RF connectors. All coax connectors are designed for individual uses, and very few connectors share exactly the same function or design specifications. However, although there are many differences between coax connectors, there Read More

Ham Radio Software, also known as Amateur Radio Software, refers to computer programs designed exclusively for ham radio equipment. Once thought to be a means of communication between radio enthusiasts, ham radio now coexists with software including data and contest loggers, log books, Morse code tutors, and antenna design aids. In the 21st century there are several software companies that have developed programs specifically for amateur radio enthusiasts. Logging Software: Freedom and Functionality Most ham radio software programs pay acute attention to the logging features of their software due to Read More

Generally, a transmission signal contains more than a single frequency. This is to say that there might be several different frequencies linked together or else superimposed on each other. This is just the way all telecommunication systems function. For example, with today's communication technology it is virtually impossible to send low frequencies without experiencing any distortion. In fact, when low frequencies are sent the distortion is frequently so severe that the signal cannot even be used. So, what is to be done with the low frequencies to make them usable? Read More

FRS (Family Radio Service) is an unlicensed service. FRS (Family Radio Service) consists of 14 UHF channels on FM. FRS Channel 1 is unofficially used as a common call channel. FRS (Family Radio Service) shares channels 1 through 7 with GMRS, and many FRS radios are also GMRS radios. The maximum allowable power for a FRS (Family Radio Service) radio is .5 watts. GMRS radios are allowed to transmit on the channels they share with FRS at 5 watts, ten times the power of FRS radios. Unlike GMRS, repeaters are Read More

A dBm is a standard unit for measuring levels of power in relation to a 1 milliwatt reference signal. dBm is similar to dB, or decibel, except that where dB is relative to the power of the input signal, dBm always relates to a 1 milliwatt signal. In other words, dB is a relative measurement and dBm is an absolute measurement. A minus sign before the dBm indicates a loss and a plus sign or no sign at all before the dBm indicates a gain. The dBm Formula The dBm Read More