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Amplification Of Small Photographic: Simultaneously from Belgium came the prediction that "the future of photography resides in the practical solution of the amplification of small photographic images."6 But enlarging did not come into general use until the introduction of more highly sensitive printing papers two decades later.
Radio-Frequency Amplifier. The power output from an oscillator is ordinarily quite low. In fact, efforts to increase the power output usually result in diminishing the fine control of the frequency. A frequency multiplier provides some power amplification but not so much as a radio-frequency amplifier. Consequently, a radio-frequency amplifier is used to take the relatively small amount of power from the frequency multiplier and build it up to a much higher level. In transmitters with an output up to about 100 watts, this amplification can be accomplis with transistors; at higher power levels vacuum tubes may be required because they ; have much higher power-handling capabilifl than transistors.
/nfermec/iafe-Frequency Amplifier. With the superheterodyne principle the intermediate-frequency (i-f) amplifier is called on to amplify signals at only one frequency, regardless of the frequency of the incoming radio signal. Such amplifiers can be much more frequency selective and provide much higher amplification than other amplifier circuits. The intermediate-frequency amplifier accomplishes the major frequency selectivity and amplification in the receiver. In simple receivers there may be only one stage of i-f amplification, but sensitive ones use two or more. Defector (Demodulator). |
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