1. Supports 0-55MHz continual adjust at 1Hz step. 2. This generator has 78L05 voltage regulate. Input current at 200MA, input voltage 8-9V would be the ideal voltage. 3. Input voltage of 12V can only be used for short time testing, otherwise will cause heat to board. 4. 5p/6p connect to encoder as per photo. 7p of the middle connects to digital matrix input. 14p (8V GND) is 8V power supply from main board. 5. If powered by main board, DDS does not need independent power supply. 1-6 correspond to 6 frequency bands: (3.8, 7, 9, 14, 18 or 21, 27 or 29). ISB, USB, CW are the three mode choices. DT is signal from main board. 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, and on and on... RIT: Fine tuning to receiving frequency CAL: Set functions KB-1 and KB-2 have common shared pin, but is not GND Specifications: Display: 1602 LCD Input voltage: DC 8V-9V Input current: 200mA Frequency range: 0-55MHz Product size: approx. 80x45x30mm / 3.15x1.77x1.2in Net weight: approx. 66g / 2.32oz Due to different product batches, the appearance may vary, which does not affect the use. Colour:As Shown Material:PC Package Contents: 1 x DDS Signal Generator Digital Module