Frequency = 75 Hz. Speed = 45 m/s
It is +75 or just 75.It is +75 or just 75.It is +75 or just 75.It is +75 or just 75.
75% of 75= 75% * 75= 0.75 * 75= 56.25
2-7d=(-75)-75= -75+75-75= 2+75-75= 77-75= 11
75*75 or 75 squared = 5625
The maxium frequency swing in FM is ± 75 kHz so 75 kHz x 60% = ± 45 kHz
The period is the reciprocal of the frequency, in other words, one divide by the frequency. If the frequency is in Hertz, the period is in seconds.
In frequency modulation system, the maximum usable deviation be fixed +- 5 KHz and test deviation be kept 60% i.e. 3 KHz for wireless telephony systems used in military and other organisations. But wide band fm systems used in commercial broadcasts having frequency deviation +- 75 KHz.
Commonly used intermediate frequencies110 kHz was used in Long wavebroadcast receivers. [1]Analoguetelevision receivers using system M: 41.25 MHz (audio) and 45.75 MHz (video). Note, the channel is flipped over in the conversion process in anintercarriersystem, so the audio IF frequency is lower than the video IF frequency. Also, there is no audio local oscillator, the injected video carrier serves that purpose.Analoguetelevision receivers using system B and similar systems: 33.4 MHz. for aural and 38.9 MHz. for visual signal. (The discussion about the frequency conversion is the same as in system M)FM radioreceivers: 262 kHz, 455 kHz, 1.6 MHz, 5.5 MHz, 10.7 MHz, 10.8 MHz, 11.2 MHz, 11.7 MHz, 11.8 MHz, 21.4 MHz, 75 MHz and 98 MHz. In double-conversion superheterodyne receivers, a first intermediate frequency of 10.7 MHz is often used, followed by a second intermediate frequency of 470 kHz. There are triple conversion designs used in police scanner receivers, high-end communications receivers, and many point-to-point microwave systems.AM radioreceivers: 450 kHz, 455 kHz, 460 kHz, 465 kHz, 470 kHz, 475 kHz, 480 kHzSatellite uplink-downlinkequipment: 70 MHz, 950-1450 Downlink first IFTerrestrial microwaveequipment: 250 MHz, 70 MHz or 75 MHzRadar: 30 MHzRF Test Equipment: 310.7 MHz, 160 MHz, 21.4 MHz
FM is the carrier property when terms like `frequency deviation' are used. Unlike AM, which has a single frequency, and the frequency is modulated by increasing the amplitude of the frequency, with FM, it's the frequency itself that is changed, either by making the frequency a bit higher or lower from the actual stated frequency. For instance, a FM radio station located at 100.00 on the dial will have the frequency deviate by plus or minus 75 kilohertz (+100.075 HZ or - 99.925 HZ.) or more commonly referred to as a bandwidth of 150 KHZ. for 100% modulation.
A period of 75 years is called a "septuagenary."
75 mHz
It can't. FM (like broadcast AM) has two *sidebands*, one at a higher frequency than the transmitter's carrier, one at a lower frequency. The modulating signal (voice, music, etc) of any trasnmitter creates one or more pairs of side frequencies within the two sidebands. A broadcast AM signal can only produce two side frequencies, so an AM transmitter at 1.5 MHz, with a 1 kHz modulating tone (fm), would put out its carrier (fc) at 1.5 MHz, a lower side frequncy at (1.5 - 0.001) = 1.499 MHz, then its carrier at 1.5 MHz, and then the upper side frequency at (1.5 + 0.001) = 1.501 MHz. The AM signal can never be wider than twice the highest modulating frequency (fm), spanning from (fc - fm) to (fc + fm), a span of 2 x fm. Be aware that special-purpose AM systems can generate just *one* sideband - we won't go into that amount of detail apart from noting it. FM signals can be wider than twice the highest modulating frequency. The complete analysis needs the mathematical Fourier Transform, but we can think of it this way. Stronger frequency modulation shows up as a larger change in the transmitted signal frequency. An FM signal at 100 MHz, modulated by a 1 KHz tone, *can* put out a lower side frequency at (100 - 0.001) = 99.999 MHz and an upper side frequency at (100 + 0.001) = 100.001 MHz. You could receive this just fine, but it would sound "weak" compared to normal broadcasts. It's possible to increase the frequency shift to (say) five times. Now, the sidebands must extend from (100 - 5x0.001) = 99.995 MHz to (100 + 5x0.001) = 100.005 MHz. How do we account for the original 1 KHz tone creating a bandwidth of 2x5 kHz? The answer is that we actually have *five* lower side frequencies, at -5, -4, -3, -2, -1 kHz below the carrier, and *five* upper side frequencies at +1, +2, +3 +4 and +5 kHz above the carrier. Notice that they are multiples of the original 1 kHz modulating frequency. These can, in fact, be shown on the instrument called a spectrum analyser. Your question? As with broadcast AM, an FM signal has only two sidebands. In FM, the strength of modulation (the modulation index) controls the number of individual side frequencies, and thus the total bandwidth of the signal. Can an FM signal have *infinite* numbers of side frequencies? Not really. It can have a *very large* number of side frequencies with very great modulation strength. In practice, this would take up *a lot* of the FM radio band, so broadcast FM commonly uses a maximum modulation index of 5.0. This means that a fully-modulating 15 kHz signal would give a bandwidth of -(15 x 5) to +(15 x 5) kHz, which is +/- 75 kHz.
The element with 75 protons in period 6 is Rhenium (Re), which has an atomic number of 75.
Frequency = 75 Hz. Speed = 45 m/s
75 years is equivalent to 3/4 of a century
The differeces between frequency and amplitude modulation does not effect the range. Fundamentally the amplitude modulation system is less efficient in that a carrier is generated, which is modulated. The modulation power is half of the carrier power. The bandwidth required is twice the highest modulating fequency. Because of the small bandwidth required, the Amplitude Modulated band on radios is from 550 Khz to 1500 Khz. Channels are separated by 10 Khz, with actual users usually separated by 2 or three channels minimum. Frequency modulation varys the frequency of the carrier by the audio modulating component. While the frequency deviation can be as low as the audio frequency modulating the carrier, better noise performance is achieved by deviating the carrier by as much as possible. In commercial broadcast operations, the 15 Khz audio signal deviated the carrier by 75 Khz. This presents exceptionally good audio reproduction. It also causes the FM (Frequency Modulated) signal to occupy a band of about 240 Khz for a 15 Khz audio channel. This compares to 30 Khz for an equivalent AM (Amplitude modulated) signal. Because of the larger bandwidth required, the FM broadcast band is moved higher in frequency. This makes the other comments about range etc come into effect. AM signals can be received even when an interfering signal is present. Weak signals can be received in the presence of strong signals. Because of this property, Aviation signals, (Airplane to control tower and tower to plane) are in AM. FM signals have an effect called "capture effect" in which a stronger signal will capture the channel and eliminate interference from the weaker signal. Basically you are trading bandwidth for interference rejection. Because of this, signals from satellites, where the signal strength is extremenly small, used to be sent in FM. Present technology uses digital broadcast techniques. Talking about digital, because of the ability of digital receivers to process signals of extremely small size, digital signals are being sent along with both AM and FM broadcast signals for either better quality, or supplementary services. Cell phones are all being switched over to digital technology for better reliability and better channel usage.