What is frequency shift keying?
962245
Hi. All de-codable signals modulate something. Amplitude or signal strength, frequency, or phase. In FSK, two frequencies are chosen and the signal changes from one to the other. This change, or shift, is used to carry the signal. Hence FSK. Found this which may help. : http://www.answers.com/main/ntquery?s=frequency%20shift%20keying&gwp=16
359870
for analog transmission, wave form\nfor digital transmission, on and off bits
556680
http://en.wikipedia.org/wiki/Modulation_index
1031386
Do you mean Fourier transform? \n\nIt's based on the idea that all signals are composed of simple sinusoidal signals at different frequencies.  The fourier transform converts a signal from time-domain, to frequency-domain. So when you go to graph the signal, instead of seeing the strength of the signal vs. time (time domain), you see it in terms of frequency (frequency domain). The Fourier transform provides an easy way to convert a time-domain signal into frequency domain, and vice-versa.\n\nThis is really nice when you want to see what parts of a signal will pass through a filter, or seeing what happens to your signal after a frequency shift, or checking sampling rates, etc.,etc.
464204
A frequency oscillator.
1155429
it means wireless fidelity
368047
Are you refering to communication to submarines.\n\nCheck out the ELF project, extremely low frequency telecommunications.
194790
See the link for a tutorial on phase shifters.  If you know how to design one you will know what they do, right?
237400
An channel in communications will allow a certain range of frequencies to pass through it without attenuating (removing) it too much. In band pass communications this is a range of frequencies in the electromagnetic spectrum (eg. 400MHz-500MHz is a possible wireless frequency. In baseband communication the range is between 0 and a certain value and this is not normally suitable for wireless communications carriers.
779558
They are called RF modulators. They broadcast to the TV on channel 3 or 4. \n\nThe problem is that the TV is not as precise as a PC monitor so if you are using it for text you will go blind looking at the fuzzy letters. If you just want to see photos from computer jpeg files it will be OK.
490702
That's because its supposed to be secret! Something like the frequency and much more. We aren't permitted to braodcast anything above permitted frequency, as a part of general public. (Frequency emission includes, usage of home-RF devices) Please make sure to get information from the military if you are making a geniune effort, other than, putting the stake at risk!
436468
More info is needed. \n\nWhat is the pass band frequency, what is the spectral content of the input signal. Ideally how steep do you want it?
93937
It is computer modem language:\n\nFor the modem to send bits of digital information in the form of 0's and 1's we need something called frequency key shifting. This is sent in wave form audio format. Now in order to get more information in and out we need to use a more modern method than just frequency key shifting thus came phase key modulation. Key phase came in and added timing delays and to designate a 0 or a 1. This allowed modems to make the transition to 9600 baud. Now in order to do even more we will add volume along with the mix. So now we have a modem that sends sounds in pitch, volume and even delay timing.
572837
RTFM\nRead the fricken Manual.
714604
Hit the shift key and the number 6
138933
You can always put a modulated signal over the 60Hz (or 50Hz if you are in other parts of the world) carrier.  There used to be a stereo system which used this concept to remote speakers around the house.
821320
There are child locks and channel locks available in present day TV's. If you want to know how they work, it is like this. There are resonant circuits for each freqency in the band width of the TV. You add up or subtract either the resistance or the capacitiance of the rc tuned circuit. Adding up to block and subtracting to activate the channel.