Niras C V\/VU3CNS<\/a><\/h4>\n![\"\"](\"http:\/\/lz4ny.eu\/wp-content\/uploads\/2017\/01\/ddsdisp.jpg\")
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DDS VFO Ver 4.0<\/h2>\n
This is a continuation of my previous DDS projects. This project uses PIC16F628A and AD9850 or AD9851. PIC16F628A is an 18-Pin microcontroller with 2K byte program memory, it is a FLASH-based and a member of the versatile PIC16F62XA family of low-cost, high-performance, CMOS, fully-static, 8-bit microcontrollers. PIC16F62XA devices have special features to reduce external components, thus reducing system cost, enhancing system reliability and reducing power consumption.<\/p>\n
The AD9851 is a highly integrated device that uses advanced DDS technology to form a digitally programmable frequency synthesizer. AD9851 generates a stable frequency and phase-programmable digitized analogue output sine wave. This sine wave can be used directly as frequency source with an output tuning resolution of approximately 0.04 Hz with a 180 MHz system clock. The AD9851 contains 6 X REFCLK Multiplier circuits that eliminate the need for a high speed reference oscillator.<\/p>\n
Features:<\/h3>\n\n- Range 0 to 70 MHz by 1 Hz step.<\/li>\n
- Freq setting in 1, 10, 100Hz, 1, 10, 100KHz, 1, 10 MHz by using a low cost mechanical encoder with a variable tuning rate.<\/li>\n
- 2 rows X 16 character LCD display.<\/li>\n
- A 4 x 3 Keypad used for easy freq entry.<\/li>\n
- IF, CW, SSB offsets settings when used with Transceiver\/ Receiver.<\/li>\n
- Software calibration to WWV or equivalent.<\/li>\n
- Two VFOs and split freq operation.<\/li>\n
- 19 user memories, memories freq + mode (i.e. LSB\/USB etc.)<\/li>\n
- All settings are held in EEPROM and are permanent (but user can change it any time).<\/li>\n
- 9 Band selection and 4 Mode selection outputs.<\/li>\n
- When operating below IF frequency, clockwise rotation of rotary encoder decreases DDS out put frequency but increases the display frequency.<\/li>\n
- RIT operation.<\/li>\n<\/ol>\n
<\/p>\n- \n
- Range 0 to 70 MHz by 1 Hz step.<\/li>\n
- Freq setting in 1, 10, 100Hz, 1, 10, 100KHz, 1, 10 MHz by using a low cost mechanical encoder with a variable tuning rate.<\/li>\n
- 2 rows X 16 character LCD display.<\/li>\n
- A 4 x 3 Keypad used for easy freq entry.<\/li>\n
- IF, CW, SSB offsets settings when used with Transceiver\/ Receiver.<\/li>\n
- Software calibration to WWV or equivalent.<\/li>\n
- Two VFOs and split freq operation.<\/li>\n
- 19 user memories, memories freq + mode (i.e. LSB\/USB etc.)<\/li>\n
- All settings are held in EEPROM and are permanent (but user can change it any time).<\/li>\n
- 9 Band selection and 4 Mode selection outputs.<\/li>\n
- When operating below IF frequency, clockwise rotation of rotary encoder decreases DDS out put frequency but increases the display frequency.<\/li>\n
- RIT operation.<\/li>\n<\/ol>\n
![](\"http:\/\/lz4ny.eu\/wp-content\/uploads\/2017\/01\/dds4v0_ckt-1-1024x724.jpg\")
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