background noise is just eliminated. Further clockwise rotation will increase the threshold level which a signal must overcome in order to be heard. Only strong signals will be heard at a maximum clockwise setting.

5.RF GAIN CONTROL: This control is used to reduce the gain of the RF (receive) amplifier under strong signal conditions.

6.SWR CAL CONTROL: This SWR CAL control allows the user to calibrate the SWR meter.

7.CLARIFY CONTROL: Allows tuning of the receive frequency above or below the channel frequency.

8.CHANNEL SELECTOR: This control is used to select the desired transmit and receive channel.

9.FRONT PANEL METER: The front panel meter allows the user to monitor incoming signal strength, RF output power and SWR level.

10.S-RF/CAL/SWR SWITCH: In the S-RF position, the meter will indicate the strength of the signal being received, as well as the relative RF output of transmission. When calibrating the SWR meter, you need to put this switch in the CAL position. To use the meter to measure the standing wave ratio, turn the switch to the SWR position.

11.ANL/OFF SWITCH: In the ANL position, the Automatic Noise Limiter (ANL) in the audio circuits is activated.

12.NB/OFF SWITCH: In the NB position, the Noise Blanker (NB) is activated. The NB is very effective in eliminating repetitive impulse noise such as ignition interference.

13.PA/CB SWITCH: Select the mode of operation. In the PA position, the radio acts as public address amplifier. Your voice will come out of the speaker that is plugged into the PA. SP. jack on the rear panel. The radio does not operate when you are in the PA mode. In the CB position, the PA function is disabled and the radio will transmit and receive on the speaker that is connected.

14.TONE SWITCH HI/LO: This switch changes tone quality in receive only. In LO position, bass is increased and in HI position, treble is increased.

15.CH19/NORMAL SWITCH: Channel 19 switch is used for instant to information channel 19.

16.TX/RX LED: The red LED indicates the unit is in the transmit mode. The green LED indicates the unit is in the receive mode.

17.ANT LED: This LED lights red when your SWR is higher than about 3:1. This is not an exact indicator of 3:1 SWR, but it is an indication that you should check your SWR reading.

18.CHANNEL DISPLAY: The channel display indicates the current selected channel.

-4 -

Page 5
Image 5
Ranger TR-127GK/DX service manual