RADIO FREQUENCY (RF) signal generator (or modulated oscillator) is an instrument that can act as a substitute for a radio station. It can be set to generate any frequency over its range and the resulting output signal level can also usually be varied before being fed to the radio under test.

This allows several things to be checked and/or adjusted in the receiver, as follows:

The Advance 62 signal generator is capable of generating frequencies from 150kHz to 300MHz over six ranges. It also features CW and tone modulation and is just the shot for aligning vintage radio receivers.

(1) the accuracy of the dial calibrations;

(2) the receiver’s sensitivity, along with its ability to handle both weak and strong signals;

(4) the amount of frequency drift in the local oscillator; and

(5) the receiver’s alignment, especially the IF (intermediate frequency) stages.

In addition, a signal generator can feed a variable or fixed-level audio modulating signal into the RF oscillator for checking the performance of the audio section of the receiver. And of course, it can provide an audio signal for directly testing audio amplifier stages.

Top of the range signal generators can also be used to perform a number of other tests on high-performance receivers. We’ll consider some of these tests later on.