Radio is the technology of using radio waves to carry information, such as sound, by systematically modulating some property of electromagnetic energy waves transmitted through space, such as their amplitude, frequency, phase, or pulse width. When radio waves strike an electrical conductor, the oscillating fields induce an alternating current in the conductor. The information in the waves can be extracted and transformed back into its original form.
Radio systems need a transmitter to modulate (change) some property of the energy produced to impress a signal on it, for example using amplitude modulation or angle modulation (which can be frequency modulation or phase modulation). Radio systems also need an antenna to convert electric currents into radio waves, and vice versa. An antenna can be used for both transmitting and receiving. The electrical resonance of tuned circuits in radios allow individual stations to be selected. The electromagnetic wave is intercepted by a tuned receiving antenna. A radio receiver receives its input from an antenna and converts it into a form usable for the consumer, such as sound, pictures, digital data, measurement values, navigational positions, etc. Radio frequencies occupy the range from a 3 kHz to 300 GHz, although commercially important uses of radio use only a small part of this spectrum.
A radio communication system sends signals by radio. The radio equipment involved in communication systems includes a transmitter and a receiver, each having an antenna and appropriate terminal equipment such as a microphone at the transmitter and a loudspeaker at the receiver in the case of a voice-communication system.

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  1. ATCclears

    Walkie Talkies are having a resurgence

    Walkie Talkies (aka two-way radios) such as these from Motorola are having a resurgence. WSJ article below. snippet: A family friend gave his 6-year-old twins two of the push-to-talk devices last year, for a way to talk to each other from different parts of the house. Now that the house is...
  2. Siglvr

    Interesting article on "patriot" radio gear and channel frequencies

    Militia and patriots, who knew. Anyway, thought it was an interesting article although it appears to be dated and uses a lot of triggering words. Remember that if you use Ham to transmit, you need a easily procured license. Finding a transmitter is easy and a fun game for ham operators, google...
  3. Frank RW

    Amateur "ham" radio...

    Any fellow hams out there? I'm Frank W4RAV in Hillsboro. Used to be K2NCC, but changed my vanity call a few years ago. Been a ham since 2005, which is a newbie to many of y'all! My MOS in the Army was 05D. Waaaay back in the 80s. :) I mostly monitor. I haven't transmitted in about...
  4. ATCclears

    Video - simple test of various antennas with HT ham radio

    Best bang for the buck: Nagoya NA-771 antenna
  5. Reno

    CB radio

    I’d like to purchase a radio to hear and be able to talk to logging trucks when I wonder the woods. I know nothing about the laws regarding what can and can not be done with or without a license. I just want something simple and cost effective. Any tips or pointers would be recommended...
  6. CLT65

    AM radio show “Shooting the Infamous AR15”

    I was listening to the radio on my way to work this morning, Armstrong and Getty, I think. One of them starts talking about how a friend took him to the range to shoot the dreaded AR15. What is it with non-gun people shooting the AR15, and going on about how special it is. I remember some...
  7. Redcoat330

    Freedom Radio Bankrupt. Who else do folks use?

    Just got an email from Freedom Munitions announcing it is in Chapter 11. I've been buying both new and remanufactured 9mm and .38 special ammo from them for the past two years. It always goes bang and seems to shoot cleanly. Wonder what happened. I won't be using them again as I'd hate to...
  8. N

    Sunday Firearms Radio Talk Shows

    Gun Talk is on KBNP 1410 AM in Portland 11am to 2pm, Sunday (right now). In Beaverton, reception for 1410 AM seems better in the morning than in the evening. The Money Station KBNP Oregon's ONLY all-business and financial news radio station 24 hours a day, 7 days a week. The Money Station KBNP...
  9. Beltfed

    CB Radio recommendation, and install

    Does anyone know where I can buy a CB Radio and have it installed? Coast area Tillamook, Seaside, And Astoria areas.
  10. james2562

    Thoughts on initial radio setup

    I am starting to venture into HAM land. I am currently studying for my technician license but still need my first radio. Out the gate I was thinking of a nice hand held (e.g. VX-8dr) but then I realized that it would be fairly limited in its use to me. I stepped back and wondered what I would...
  11. Oathkeeper1775

    Ham Radio Classes & Testing; Salem Area

    I do not have an angle; only sharing information. Testing $5.00 Salem, Oregon VE Sessions Classes with 2 meals $27.00 Ham Radio Classes in Salem, OR
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