Definition of letters used for short wave radio transceiver equipment

We will see a variety of English abbreviations on various radio transceiver equipment. Today we will talk about the meaning of some of the English names used on HF shortwave radios.

Transmit Part

VFO --- Variable frequency oscillator. Adjusting the frequency of the transceiver is achieved by changing the VFO frequency. For ease of use, some machines are equipped with two oscillator circuits, VFO A and VFO B, which can respectively preset the frequency. You can easily select the different operating frequency through a button.

RIT --- Fine tuning of receiving frequency. When making contact, sometimes it is necessary to adjust the receiving frequency and keep the transmitting frequency unchanged. The RIT function can achieve this goal.

Scan --- Continuously scan the band without turning the frequency knob.

AGC --- Automatic gain control.

RF Gain --- High frequency gain control. It changes the gain of the high-frequency amplifier stage.

RF ATT --- High amplifier attenuation. Attenuate through it when encountering a strong signal.

RF OUT --- High frequency output. This interface is generally on the back of the machine for connecting to other devices.

AF Gain --- Audio gain control. Used to control the volume.

EXT SP --- External speaker interface.

MONI --- Monitor control.

CW N/W --- Wide and narrow band selection of band pass filter in short wave radio.

NOTCH --- If you encounter a narrowband signal interference (such as a CW signal) in the received signal, use this function to attenuate it.

SHIFT/WIDTH (USB, LSB) --- IF sideband selection and bandwidth control.

SQL --- Squelch level control.

NB Level --- Noise reduction start control level selection. This kind of noise reduction circuit is generally effective for pulse interference, and its principle is "cancellation anti-interference", that is, the interference pulse is inverted and added to the original pulse signal to cancel it.

PHONE --- Headphone jack.