DR4020 is a 40/20 metres dual-band radio for digital modes that requires a computer with specific applications to use. The signal inputs and outputs have a 1:1 isolation transformer to electrically isolate the radio from the computer and reduce interference.
External Power Supply. Any 10-14V DC supply or battery pack with a current greater than 1A can be connected via an external power connector. Polarity protection circuit available inside the radio.
Antenna. Any resonant antenna can be directly connected to the antenna interface (ANTENNA) with a BNC connector, and an antenna tuner should be connected between the antenna interface and the antenna for a non-resonant antenna. 3.5 mm stereo socket (DATA IN/OUT on DR4020).
DR4020 can be used with a PC, Laptop or Raspberry Pi. An external USB sound card may be required if you use Raspberry Pi to connect to DR4020. While using a laptop, and if there is only one combined AF/MIC jack, please pay attention to the different wirings of the computer audio jacks below:
Power Switch. Power switch PWR On the left side of the panel, press PWR to power on, and press PWR again to turn off.
Band and Frequency Selection. Short press the right VFO knob of the panel to select between 40 meters and 20 meters. Rotate the VFO knob to change the stored working frequency. The storage frequency of each band is from MEM-01 to MEM-05. If you press this knob for more than 2 seconds, it will enter the VFO function, and you can change the frequency of the stored frequency. When the desired frequency is turned, you can press the knob again for 2 seconds. SAV will be displayed on the screen, and this new frequency will be stored in the corresponding memory frequency and exit the VFO function. A short press of this knob will not save the new frequency and exit the VFO function.
Transmitting (VOX). Transmit is by the input audio signals from DATA IN， when the input signals are greater than the trigger level, it is automatically switched to transmit. The red LCD marked TX in the upper left corner of the panel is illuminated when transmitting, its brightness indicates the output power level, and RX in the lower right corner of the LCD becomes TX.
Computer Settings. The MIC gain of the computer is generally set to the maximum. If the application software shows that the input level is too high, the MIC gain can be appropriately reduced. The radio’s transmitting can be adjusted using the tuning function in the application software. Adjust the volume output of the computer from low to high. When the output level exceeds the trigger level, the radio will be triggered to switch to transmit.
Continue to increase the volume. The power of the output station will increase, and the power of the radio will not increase with the volume. The time is the best volume output position, and then increasing the volume will not increase the power of the radio. Observing the radio’s transmit power can be judged according to the current of the radio’s power supply. The higher the current, the greater the power. If the power supply does not have a current meter, you can also observe the brightness of the radio’s red indicator light TX to roughly determine the transmit power.
- Weights: 320 g
- Output: 4 – 5W (12V)
- Filter BW: USB 400 – 2800 Hz
- Operating Voltage: 10 – 14 VDC
- Frequency: 7.0 – 7.2 MHz, 14 – 14.5 MHz
- Full Power: 70 MPV 40 m, 120 MPV 20 m
- Current: 50 mA RX, 700 – 800 mA（12V)
- Control Audio Voltage: Less than 30 MVP
- Memory: 5 memories per each band, user defined
- Dimensions: 88 x 38 x 124 mm (buttons are excluded)
Note: Specifications are subject to change without notice or obligation.