Amateur Radio (Ham Radio) is a hobby pursued by individuals all overs the world for recreation, non-commercial exchange of messages, experimentation, self-training, and emergency communication. Amateur radio service is established by the International Telecommunication Union (ITU) through international agreements. National governments regulate transmissions and issue stations licenses with a Call-Sign.
Radio communication equipment typically consists of a transmitter, a receiver (or a combination called transceiver), a transmission line, an antenna along with several other peripheral devices like microphone, Morse key, etc. An amateur radio operator usually operates from a room full of these equipment. This is call a Ham Radio Shack. A ham shack is sacred to a ham operator where he would spend considerable time pursuing his hobby.
The ability of radio waves to propagate over vast distances through atmosphere or vacuum is the life blood of radio communication. If radio wave propagation did not exist, there would be no radio communication. Radio waves propagate from one point to another by various means. The propagation phenomena is intricate. It varies under various conditions. This is what make radio communication so interesting.
The amazing ability to reach out to distant locations around the world and millions of miles through space for inter-planetary communication without setting up a physical interconnecting medium is what makes radio communication so distinctive from other methods like cables and fiber-optics. Radio provides a true global outreach for terrestrial communication while being able to propagate endlessly through outer space.
Antenna is perhaps the most vital part of any radio communication infrastructure. It is the launchpad, a port that couples to the vast, expansive and intangible radio propagation medium. In the absence of an efficient antenna, radio communication over long distances and over hostile propagation environment would be quite untenable. In our view a good antenna is very vital. Hence we will be placing a lot of emphasis on antennas.
Test and measuring equipment find a very important place in the shack of a radio amateur with a technical bent of mind. A bench full of a variety of test instruments to measure various parameters is a common sight. They are used during design, development, alignment and performance testing of wireless rigs and associated peripherals. However T&M is not meant only for the technically inclined. A few basic instruments are needed by all operators for optimizing station performance.
One of the fundamental objectives of ham radio is experimentation and self-training. A good ham operator should be able to establish communication under hostile and emergency situations when fancy commercial rigs are not accessible. You should be able to setup a function radio station with parts and sub-assemblies at your disposal. This is when home-brewing experience will either make or break the day. Even otherwise it is a very fulfilling experience.
Space or satellite communication adds a whole new dimension to ham radio. It opens up new vistas demanding new skills and techniques. Low Earth orbiting (LEO) amateur satellites have been used since decades by ham operators to establish VHF/UHF contacts across great distances using cross-band satellite transponders. The earth's natural satellite, the moon has also been successfully used as a passive reflector to bounce signals back to earth in EME communication.
Fascinating Amateur Radio Communication
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A typical amateur radio operator has a room full of wireless radio equipment. This is the Ham Shack. Mostly they are radio receivers, transmitters, or transceivers. Some of these could be of commercial origin while others could be self-made or home-brewed by amateur radio operators themselves. Other stuff may include antenna tuners, power supplies, SWR meter, etc.
As amateur radio operators, we all learn how to operate our station equipment effectively. However many of us seldom go beyond this stage. To get a better understanding we need to look under the bonnet. We need to figure out the limitations and strengths of our station equipment. We need to understand the various vital specification, parameters, and other important factors that are responsible for our transmitter, receiver, and other station equipment to perform as they do.
You will find a variety of articles and post about radio equipment on this site. Articles cover the theory, construction, and operation of amateur radio communication equipment. Apart from traditional radio equipment designs, modern concepts and technologies like Software Defined Radio (SDR), Digital Signal Processing (DSP) using either computer-based software or dedicated programmable hardware devices, Micro-controllers, Field Programmable Gate Arrays (FPGA), etc are covered in this website…. Read More.
The wonder world of HamSphere 4.0 is a true gift of modern technology. It is the ultimate virtual amateur radio system. Unparalleled and unmatched in performance it has an uncanny resemblance to real HF SSB radio. HamSphere 4.0 offers VHF/UHF FM radio with simulated repeater networks, including vast paraphernalia of a realistic virtual HF amateur radio support system.
The strength of HamSphere is an accurate HF propagation model that tracks nature and replicates ionospheric behavior on a minute-to-minute basis. Solar activity and SSN determine propagation behavior. Exotic HF propagation modes like the Gray-line, Chordal hops, Trans-equatorial propagation, back-scatter, winter anomaly, etc are all simulated. HamSphere sounds and behaves like the real HF radio with both normal and split frequency operating capability.
HamSphere 4.0 offers a complete virtual amateur radio environment. It comes with a highly salable modular transceiver designed to match the best hardware transceiver. A plethora of realistic virtual antennas is available on HamSphere. This opens up a whole new world of ham radio for all. The experience is awesome which captivates the old-timer. It is also a boon for a new operator.
You don’t have to worry about going wrong and burning up your linear PA or melting antenna traps. Those with limited space in urban localities can now experience all the goodies of HF radio without having to put up big physical antennas. For the senior operators, no climbing of towers to make that little adjustment. The niche technology of HamSphere brings everything to your laptop…. literally as well as figuratively… Read More.
Radio signal propagation from one location to another is vital for radio communication to exist. Various propagation modes come into play depending on the frequency band in use. At VHF/UHF and higher frequencies, the atmosphere of the earth has a significant effect on terrestrial propagation. However, for satellite and space communication several other factors like Doppler shift, Faraday rotation, etc also play a role. HF radio propagation is quite a different ball game. It is very interesting and intriguing the way the Ionosphere plays a major role in long-distance communication.
Ionospheric layers are dynamic in nature. They constantly change based on diurnal, seasonal, and many other factors. The declination of the earth and the activity of the sun play a very vital role. Proton flux, X-ray, and several other EM and particle emissions from the sun determine our ability to maintain HF radio communication on earth. At even lower frequency bands like MF and LF where the ionosphere has far less influence, we encounter the phenomena of surface wave propagation in its full strength and glory.
In the propagation section of our website we dwell deep into these topics with articles and posts. We try to follow the mysterious and fascinating science of radio propagation from the perspective of an amateur radio communication. With clear and concise articles we endeavor to make this intricate subject relatively easy to understand…. Read More.
The antenna is the most vital part of any radio communication station. The antenna determines the efficacy of the radio station and consequently its ability to establish long-distance contacts through a hostile propagation environment. All amateur radio old-timers know this very well. A radio station is as good or bad as its antenna. Contrary to popular belief, it is not the transmitter power output but a good and effective antenna that enables good two-way contact. An average amateur radio operator does not work with very high TX power, yet communicates successfully around the world.
The need for a good antenna can never be over-emphasized. Unlike a power amplifier that gives us the advantage in only one direction of a two-way QSO, a better antenna leverages the advantage during both TX and RX. During TX a good antenna emulates a linear amplifier. Due to its gain, it produces higher Effective Isotropic Radiated Power (EIRP). This is akin to using a PA. During RX, the gain of the antenna manifests itself as a bigger aperture thus giving it the ability to effectively pick up weaker signals. There is no point in putting out more TX power alone. Unless we hear the far-end station we cannot work him.
I have always invested time, effort and money in ensuring that I have the best possible and well-tuned antenna. In the antenna section of this website, we discuss them threadbare. Various parameters of antennas, how to choose, what factors are important while deciding and how to set up amateur radio antennas are all discussed… Read More.
In the present day and age, amateur radio operators have many choices. All types of ham radio equipment including transceivers, peripheral station equipment, antennas, etc are all available at a price from commercial manufacturers. These types of equipment are adjusted and tuned at the factory. They follow the plug-n-play paradigm. It is thus a fairly trivial task to set up a functional amateur radio station.
It is an age of instant coffee and 2-minutes-noodles. A majority of amateur radio operators use commercially fabricated rigs and enjoy the hobby. Although there is nothing wrong with this approach, unfortunately, this leaves little room for tinkering and experimentation. Yet there are many who still like to do things their own way by exploring, experimenting, and designing/fabricating their rigs.
For those who wish to transcend the boundaries of radio as only an art, broaden their perspective, and dwell deeper into the science and technology of radio communication, a tacit understanding of RF measurement and general test and measurement techniques (T&M)would play a vital role.
We have devoted a full section of this website to measurement techniques. Over a period we intend to progressively explore various nuances of RF measurement with reference to transmitters, receivers, transmission lines, antennas, and much more. We will cover all aspects of HF, VHF/UHF, analog, and digital measurements. Various technical parameters, their relevance, test setups, required equipment and measuring procedures that are vital to amateur radio communication will be highlighted and discussed… Read More.
Although analog radio-telephony is the most popular mode of communication on amateur radio bands, various digital data modes are also quite extensively used. These modes have their own pros and cons. Any mode of communication that uses binary symbols at base-band levels or those modes that require machines to encode or decode information are clubbed here under this category.
CW or Morse code is perhaps the world’s oldest method of radio communication. It is indeed a digital mode because signals have binary states. However, it is unique due to the fact that it does not need machines to encode or decode. It is human-friendly and rather than being a code, it is actually more like a language of pleasant-sounding musical notes. CW is very robust and can be used with simple equipment and has the ability to perform under the most hostile communication environment where all other methods fail.
Amongst classical amateur radio Digi-modes, RTTY is the oldest. PSK31, MFSK, QPSK, MT63, Olivia, Hellschreiber (Feld Hell), Throb, Thor, Contestia with many sub-flavors are some of the popular digital text or file transfer modes. A relatively new kid on the block is ROS, a wonderful weak signal robust digital protocol system. It provides DSSS, as well as FHSS, spread spectrum modes.
Nowadays, another mode called FT-8 which is an offshoot of JT-65 has taken the amateur world by storm. Although they are technological marvels allowing very weak signal communication, they are rather drab since they use a restricted format and do not allow free-form text. Although analog SSTV is essentially an analog mode using FM base-band sub-carrier modulation, we place it under this category since it requires machine encoding and decoding…. Read More.
The first human effort to venture into the realm of space communication started with the launch of the Russian (erstwhile Soviet Union) Sputnik space orbiter in October 1957. Sputnik was placed in an elliptical orbit and sent out regular message transmissions. The signals were strong enough to be picked up by amateur radio stations all over the world.
Since then technology has grown by leaps and bound. We have a very mature space technology with not only numerous communication satellites in Geo-stationary orbits but also a variety of application-specific satellites in Low Earth Orbit (LEO), polar orbits, and highly elliptical orbits. Other than this we also have deep space communication capabilities for exploring our planetary system and beyond.
Amateur radio is never far behind. We hams have our own radio communication satellites, often colloquially called AMSAT. Cross-band radio linear transponders are used for two-way radio communication by amateur radio operators around the world. Other than this, we have smaller Cube-Sat satellites with interesting features and they normally have cross-band FM repeaters. The International Space Station (ISS) also makes regular QSOs with amateur radio operators all around the world.
Amateurs now also have access to a Geo-stationary satellite (Es’hail-2) with an S-band/X-band transponder and having a very large footprint covering Europe, Asia, and Africa. Another very interesting field of ham radio activity is Earth-Moon-Earth (EME) communication. The moon is used as a passive reflector to bounce back radio signals back to earth. EME is a very interesting and challenging activity…. Read More.
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Our effort is to foster healthy discussion amongst members in matters related to amateur radio and radio communication science and technology in general. Questions and queries can be made by those who wish to seek information. These will either be answered by the peer group in the course of discussion or by the panel of experts. Article or post requests on specific topics made via the forum will also be taken up.
After a simple registration, members will gain full access to the forums for the purpose of posting. However, any visitor who chooses not to register will still be free to browse the forums. Please check it out… Read More.
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