0~55MHz DDS Signal Generator AD9850 Direct Digital Synthesis For HAM Radio DIY Description: 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. Input 12V (Seller's Note: We are also providing a simplified version, with input 8~9V) With direct digital input frequency With audio volume potentiometer With amp. gain potentiometer With AGC potentiometer S-LED display Standing Wave-LED display Keys & 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. 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 encoder switch to adjust value. Operate in accordance with STEP 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 encoder switch to adjust value and in accordance with STEP key. Press CAL then quickly release to enter step D. D: MAX_RX_DDS_FREQ:Setting maximum working frequency. Use encoder switch to adjust value and in accordance with STEP 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 encoder switch to adjust value and in accordance with STEP key. Press CAL then quickly release to enter step F. F: CW_OFFSET:Fine tuning for CW working mode. Use encoder switch to adjust value and in accordance with STEP 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 encoder switch to adjust value and in accordance with STEP 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. Notes: 1. DDS SYSTEM CLK: can use frequency tester to get 30MHz oscillator, multiply the tested value at 6, then put the multiplied value here. If using AD9851, make initial setting at 180000000. 2. OFFSET FREQ: can be set as + or - . Rotate encoder switch to change value, press STEP key, then rotate encoder switch to adjust step. Minimum working frequency plus (+) offset frequency should be high than 0 (zero). Frequency display: RX = MULTIPLIER x (RX_DDS_FREQ + OFFSET_FREQ) TX = MULTIPLIER x (RX_DDS_FREQ + OFFSET_FREQ + TX_OFFSET_FREQ) The frequency programmed into the DDS, is calculated as shown below. RX = ABS(RX_DDS_FREQ) TX = ABS(RX_DDS_FREQ + TX_OFFSET_FREQ) RX_DDS_FREQ, MIN_RX_DDS_FREQ, MAX_RX_DDS_FREQ, TX_OFFSET_FREQ & OFFSET_FREQ Examples: 1. DDS output range 30~40MHz: MIN_RX_DDS_FREQ MAX_RX_DDS_FREQ OFFSET_FREQ RX Frequency display range. 30 MHZ 40 MHz 100 MHz = 130 MHz to 140 MHz. \ Note 1 30 MHZ 40 MHz -10 MHz = 20 MHz to 30 MHz. / -40 MHZ -30 MHz 170 MHz = 140 MHz to 130 MHz. \ Note 2 -40 MHZ -30 MHz 60 MHz = 30 MHz to 20 MHz. / 2. setting FT180A with DDS: ENABLE RPT NO X6 RECLK X6 DDS SYSTEM CLK 180M MAX DDS FREQ 65M MIN RX DDS FREQ 10.701M (Offset frequency + RIT frequency) MAX RX DDS FREQ 60M TX OFFSET FREQ 0 MAX RIT OFFSET 1K (RIT frequency) OFFSET FREQ -10.700M -(Offset frequency) MULTIPLIER 1 Shipping & Handling Policy Generally, delivery time is 10-20 business days to USA, United Kingdom, Australia and 15-30 days to most other countries. All orders will be processed within 48 hours from the date of payment .The delivery confirmation will be sent ebay message when your order is processed We will make shipment according to the address you put on eBay, if you want us to ship items to a different address please contact us before making the payment. International Buyers Note: 1) Import duties, taxes and charges are not included in the item price or shipping charges. These charges are the buyer's responsibility. 2) Please check with your country's customs office to determine what these additional costs will be prior to bidding/buying. Payment Policy We accept Paypal only. Returns Policy We always take customer service seriously and want you to be 100% happy with your shopping experience here. If you are unsatisfied with our item or service, then please follow the good eBay practice to contact us before leaving any feedback and return it within 14 days for a replacement or money back. Please contact me before you return it. Buyer is responsible for the shipping cost of return postage. Shipping and insurance costs will not be refunded. We are committed to resolve all issues in a friendly and satisfactory manner. Contact us If you have any problems, we are very glad to help you. We are handling large volume emails every day. Please allow us to reply your email within 24hrs Feedback Dear buyers, we appreciate your business, if you are satisfied with our service, please leave us a positive feedback . When you rate the shipping time part please take international transit into consideration. Your recognition will make us more confident to develop business and serve you better. Our goal is to make sure you are a happy buyer and pleasant shopping with us. Please email us before leaving any 1 or 2 ratings, negative feedback or open any dispute. We understand the concerns and frustrations you might have, and will do our endeavor to resolve the issues. Please give us the opportunity to resolve any problem. thank you ! On Dec-18-12 at 05:33:08 PST, seller added the following information: On Sep-21-14 at 18:06:18 PDT, seller added the following information:
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