In order to achieve both good image rejection and selectivity, many modern superhet receivers use " two " intermediate frequencies; this is called a " dual-conversion " or " double-conversion " superheterodyne.
12.
There is a second frequency conversion ( making a triple-conversion receiver ) that mixes the 81.4 MHz first IF with 80 MHz to create a 1.4 MHz second IF . Image rejection for the second IF is not a major problem because the first IF provides adequate image rejection and the second mixer is fixed tuned.
13.
There is a second frequency conversion ( making a triple-conversion receiver ) that mixes the 81.4 MHz first IF with 80 MHz to create a 1.4 MHz second IF . Image rejection for the second IF is not a major problem because the first IF provides adequate image rejection and the second mixer is fixed tuned.
