TRANSCEIVERS

Table 1-3.—Decibel to Power Ratio Table 1-4.—Logarithms receiver’s sensitivity drops to -107 dBm. Since a loss of 3 dB reduces the sensitivity by 1/2, the input signal will have to be twice as large to be detected. TRANSCEIVERS A transceiver is a unit, usually enclosed in a single case, that combines a transmitter and receiver using a common frequency control. Transceivers are used ex- tensively in two-way radio communications at all fre- quencies, and in all modes. The primary advantage of using a transceiver rather than a separate transmitter and receiver is cost. In a transceiver, many of the components can be shared during both transmit and receive operations. Another advantage is that transceivers can be tuned more easily than separate units. A disadvantage of using a transceiver is that while duplex operation is not possible with most trans- ceivers, communication must sometimes be carried out on two different frequencies. Although this is a 1-11