Features: This is a 0~55MHz DDS Signal Generator. It is based on AD9850 chip and is very easy to operate. Supports 0~55MHz continual adjust at 1Hz step. This generator has 78L05 voltage regulate. Input current at 200MA, input voltage 8-9V would be the ideal voltage. Input voltage of 12V can only be used for short time testing, otherwise will cause heat to board. 5p/6p connect to encoders as per photo. 7p of the middle connects to digital input. 14p (8V GND) is 8V power supply from main board. 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. Specifications: Display: 1602 LCD Input voltage: 8V-9V Input current: 200mA Frequency ranges: 0-55MHz 6 bands: 3.8,7,9,14,18 or 21,27 or 29 Material: Metal and Plastic Size: approx. 82x45mm/3.23x1.77in Quantity: 1Pc Keys & Connection interfaces: ENC: encoders switches MEMERY: switches 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. How to operate: Press CAL, power on, then we enter setting screen. Let go/release CAL. A: ENABLE 6XREFCLE: setting chip clock mode, adjust frequency encoding setting. AD9851 set to 6-multiply frequency, AD9850 set to 1multiply frequency. Press CAL then quickly release to enter next step B. B: DDS-SYSTEM-CLK: Chip working frequency setting. Use encoders switches to adjust value. Operate in accordance with STEP for key. AD9851 set at oscillator 6-multiply channel, AD9850 set at actual output of oscillator. Press CAL then quickly release to enter step C. C MIN_RX_DDS_FREQ:Setting minimum working frequency. Use encoders switches to adjust value and in accordance with STEP for key. Press CAL then quickly release to enter step D. D: MAX_RX_DDS_FREQ:Setting working frequency. Use encoders switches to adjust value and in accordance with STEP for key. (Smaller than 60MHz would be OK ). Press CAL then quickly release to enter step E. E: SSB_OFFSET:Fine tuning for SSB working mode. Use encoders switches to adjust value and in accordance with STEP for key. Press CAL then quickly release to enter step F. F: CW_OFFSET:Fine tuning for CW working mode. Use encoders switches to adjust value and in accordance with STEP for key. Press CAL then quickly release to enter step G. G: OFFSET_FREQ:Setting of offset Frequency. e.g, set to 9MHz or 10.7MHz, use encoders switches to adjust value and in accordance with STEP for key. Press CAL then quickly release to enter step H. H: MULTIPLIER: multiply setting for frequency. Should be set as 1, press CAL then quickly release to enter step I: I: Screen displayes word "SAVE", automatically save the above setting, and returns to normal working. Package Includes: 1pc DDS Signal Generator Digital Module note: No retail package. Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item.