1Support 0-55MHz continuous adjustment, the frequency is 1Hz. 2The generator has a 78L05 voltage regulator. When the input current is 200MA, the input voltage of 8-9V will be the ideal voltage. 3The 12V input voltage can only be used for short-term testing, otherwise it will cause the board to heat up. 45p/6p connect to encoder as per photo. 7p of the middle connects to digital matrices input. 14p (8V GND) is 8V power supply from main board. 5If powered by the motherboard, the DDS does not require a separate power supply. 61 to 6 correspond to 6 frequency bands: 3.8, 7, 9, 14, 18 or 21, 27 or 29. 7ISB, USB, CW are the three mode choices. 8DT is a signal from main board.Item Type: Signal Generator Display: 1602 LCD Input Voltage: DC 8V-9V Input Current: 200mA Frequency Range: 0-55MHz 6 Bands: 3.8, 7, 9, 14, 18 Or 21, 27 Or 29 Product Size: Approx. 80 x 45 x 30mm / 3.15 x 1.77 x 1.2in Keys and Connection Interfaces: ENC: Encoder switch MEM: Switch for memory mode VFO: Transfer from VFO A to VFO B, or from VFO B to VFO A. SSB: Working mode change: circulate from USB, LSB, AM, CW, then keep looping... RIT: Fine tuning to receiving frequency CAL: Set functions KB-1 and KB-2 have common shared pin, but is not GND1 x Signal Generator