This page is designed to serve two purposes. I intend to allow current Ham Radio Operators and Scanner Enthusiasts to find a wealth of useful information, and also to introduce others to ham radio and scanners. I have been a ham radio operator since 1996- licensed as a technician until 2015 when I upgraded to a general license and began the journey of HF DX.
What is relatively obvious if you think about it but what is overlooked by many is that anything that is communicating with something else and it is not connected to it in some way by a cable or other means, is utilizing wireless communications to reach this end. The most commonly used form of wireless communciation uses radio waves to communciate. A transmitter uses an antenna to generate an electromagnetic field at a specified frequency which creates a wanted disturbance that is radiated from the antenna. Then a receiver uses an antenna to pick up the electromagnetic radiation on that frequency. Widespread use of wireless radio communications is one of the most noticeable advances in the latter half of this century. Frequencies are rated in Herts (Hz) after Heimrich Hertz. One Hert is the same as one cycle per second (CPS)- a cycle is the time it takes an audio or radio wave to move from peak to peak. Another way to express a frequency is the distance from peak to peak and this is ususally expressed in meters and used commonly by Ham Radio Operators. To give you some idea of the range of the frequency spectrum, humans can hear audio frequencies from about 20 Hz to 20,000 Hz (20 kHz). From 0 Hz to 20Hz are sub-audible frequencies primarily used by elephants and whales to communicate over hundreds of miles. Above 20 kHz, other animals use audio frequencies for communications and humans use radio frequencies (RF) for communciations. Bats, for example, use such frequencies for navigational purposes via echolocation. Dogs can hear much higher frequencies than humans which is why we use "dog whistles" to train dogs- they hear it but we don't. The radio frequency spectrum is divided into thousands of categories and usage groups by the Federal Communications Commission in the United States. Some form of order is required in allocation of frequency bands or there would be "frequency anarchy" and nothing that used radio communications would work right- there would be too much radio interference. Remember that 1 kiloHert (kHz) = 1000 Hz, 1 MegaHert (MHz) = 1000 kHz, and 1 GigaHert (GHz) = 1000 MHz. The RF Spectrum is divided into several diffrent regions:
VLF Very Low Frequencies (30 Hz to 30 kHz) LF Low Frequencies (30 kHz to 300 kHz) MF Medium Frequencies (300 kHz to 3 MHz) HF High Frequcnies (3 MHz to 30 MHz) VHF Very High Frequencies (30 MHz to 300 MHz) UHF Ultra High Frequencies (300 MHz to 3 GHz) SHF Super High Frequencies (3 GHz to 30 GHz) EHF Extremely High Frequencies (30 GHz and above)
Above radio waves in the frequency spectrum are microwaves, infrared radiation, visble light, ultraviolet radiation, x-rays and gamma rays. Some spectrum related links are Radio Spectrum, Army FCIM List, and NTIA/OSM. Without a Ham License, in the United States, for the most part the only frequencies you can transmit on without another license are used by cordless phones, cellular phones, baby monitors, short-range 49MHz walkie talkies, telemetry devices, and other low range, low power systems. Ham Radio Operators with high class licenses have the ability to broadcast in virtually every area of the RF Spectrum. Some Ham's are capable of boucing signals off the moon and back to the earth using low frequencies. Generally lower frequencies are capable of longer-range communications becasuse they utilize sky-wave propagation which essentially means that the signal bounces off the ionosphere and around the globe. In rear situations of numerous solar storms, the ionoshere's charge increases and "skip" is possible on even higher frequencies. I live in Indiana and a few summers ago, I turned on my CB (27 MHz) and heard Mexicans speaking spanish flooding the channels- I'm sure they probably heard Americans doing the same. Skip can be good because it can allow easier DX (long-distance) communications, but it can also be bad because lower frequencies can get flooded with far away unwanted communications. There are 4 classes of Ham Radio Operator Licenses- each with diffrent frequencies available for communications and diffrent transmission power limits. They are as follows:
The Technician license has become a popular first license. The Amateur Radio Relay League (ARRL) is one of the most popular national Ham Radio clubs. If you are interested in getting a Ham license, request the "New Ham Information Package" from the ARRL. for Hams. To acquire an Amateur Radio Operator's License (Ham License) from the FCC, I would recommend visiting your local Ham Radio Store and purchasing the ARRL's book "Now You're Talking- Everything you need to get your first Ham License." - that covers the material that you will encounter for a Novice or Technician Exam. The tests are admisitered by 3 Volunteer Examiners (VEs) who vounteer their time to test those who wish to get a ham license. To see when then next ham exam is being held near you visit the ARRL's list of VE tests. Each testing session costs $15. You find out right away whether you pass or fail. If you fail, you may retake an element for an additional $15. An alternative to the ARRL's book are KB6NU's No Nonsense Study Guides - they are quick and to the point and will help you pass the exam, but you won't learn a lot other than what is on the exam- but the nice thing is the technician guide is a free PDF! Then, once you have read up, I strongly recommend the flash cards, and then the practice tests at HamStudy.Org - they are a great way to master the test questions. Once you pass the test, you must wait until you find out what your callsign is before you can legally broadcast on Amateur Radio bands. There are several places on the net that can help you find your callsign as soon as the FCC issues it. Now that I've explained the basics of wireless radio communications and the frequency spectrum, it is rather easy to describe a scanner. Ham radios are actually transcievers which both transmit and receive on certain frequencies- some can even be modified to transmit outside Amateur bands so you can transmit on police or fire frequencies if you are authorized to do so. A scanner, however, is just a receiver. Scanners are used to listen to what is being broadcast virtually anywhere on the frequency spectrum. People use scanners to listen to everything from police to aircraft. Most scanners cover frequencies from roughly 30 MHz to 1 GHz or thereabouts. All scanners vary in form and function. Basically, you program certain frequencies that are commonly used in your community and it will constantly search those frequencies and stop if it hears something. Just remember, if its in the air, a scanner of some sort can surely pick it up. A RADAR detector is essentially a scanner that sounds an alarm when it detects signals on a certain frequency (X-band: 10.252 Ghz, K-band: 24.150 Ghz, Ka-band: 33.4 Ghz to 36.0 Ghz (also known as Super Wideband Ka).