Radio Frequency (R.F) Signal Generator Introductory Statement & Uses

Radio Frequency (R.F) Signal Generator Introductory Statement & Uses Points : Radio Frequency (R.F) Signal Generator Introductory Statement & Uses The radio frequency (R.F) generator is a convenient source of test signals over the radio frequency range. These signals are used to align and test the gain and frequency response of electric and electronic equipment that operates at radio frequencies, such as AM, FM, TV, microwave and radar, transmitters, receivers & even transmission lines gain.

The basic circuit of an RF generator is a variable frequency RF oscillator. The frequency range of a particular RF generator depends on its intended application because of the wide variety of equipment operating in the RF spectrum. A typical frequency range is from 50 KHz to 110 MHz. A calibrated frequency control dial is used to vary the oscillator output frequency. The frequency band is usually divided into several convenient ranges, selected by range or band selectors. These operate with the variable calibrated dial. The primary output signal is a continuous — wave (CW) sine wave, called the RF carrier signal.

The amplitude of the RF signal is made adjustable by a gain and or an attenuator control and the signal is supplied via RF output terminals. Various other features may be built into the RF generator depending on its design and manufacture. These are:

1. A crystal oscillator and detector used to calibrate the RF output frequency.
2. A fixed frequency audio output, usually 400 Hz or 1000 Hz, used for signal tracing.
3. An internal or external method of modulating the RF carrier to provide an amplitude (FM) sweep output.
4. A carrier/modulation meter used to monitor the RF output level or percent of AM modulation,

Typical sweep frequency outputs of an RF generator are centered about 455 KHz and 10.7 MHz, the intermediate frequencies (IF) commonly used in AM & FM receivers.