You may have heard of "AM Radio" and "FM radio", "VHF" and "UHF" television, "civilian band radio," "shortwave radio" and other terms. That you have not thought of them mean? What is different between them? 4g cell phone jammer
Radio Frequency 4g cell phone jammer http://www.4gcellphonejammers.com/
A radio wave is an electromagnetic wave propagating through the antenna. Radio waves having different frequencies, and the radio receiver may be tuned to receive a particular signal of a specific frequency.
In the United States, the Federal Communications Commission (FFC) holds the reins of radio use, if there is a specific radio frequency to be used also filed an application to the Commission. For more detailed information about the radio waves, see the radio works. 4g cell phone jammer
When you listen to radio stations, you will hear the announcer say, "You're listening to 91.5FM WRKX The Rock", which means that you're listening to radio station frequency is 91.5MHz FM radio broadcast signal, and the FCC do this assigned call sign is WRKX. Megahertz means "one million cycles per second," so 91.5MHz radio transmitters are expressed at a frequency of 91.5 million cycles per second oscillation. The FM (frequency modulation) radio to that frequency modulation radio, you can clearly receive this station. FM radio stations are all between 88MHz and 108MHz band transmission signal. Radio spectrum band used only for FM radio broadcasts. 4g cell phone jammer
Similarly, the frequency of AM radio is limited to 535 kHz band -1700 kHz (kilo means thousand, so as per 535 000 -170 million cycles). Therefore, if AM (amplitude modulation) radio station, said, "This is AM680WPTF", meaning that radio station is broadcasting 680 kHz AM radio - signal, and FCC call sign is specified for this WPTF.
Common bands include:
AM radio broadcast --535 kHz -1.7 MHz
-26.1 MHz shortwave radio --5.9 MHz band
Civil band (CB) radio --26.96 MHz -27.41 MHz
Television - Channel 2-6 of 54-88 MHz
FM radio broadcast --88 MHz -108 MHz
Television - Channel 7-13 of 174-220 MHz
Interestingly, you can imagine each wireless technology has its unique small band. There are hundreds of such techniques, for example!:
Garage door openers, alarm systems, etc. - about 40 MHz
Standard cordless phones: 40-50 MHz frequency band
Baby Monitor: 49 MHz
Radio control aircraft: about 72 MHz
Radio Control Car: about 75 MHz
没有评论:
发表评论