40MHz DDS VFO Programable Module

0-40MHz VFO & Short Kit for AD9850 DDS Module

This board will control one of the small AD9850 DDS modules available on eBay. It supports a 16x2 line LCD display showing the operating frequency, band and step size. The frequency can be adjusted using either a rotary encoder or two push buttons. Two additional buttons are used to select the frequency band and frequency step size.

New Version 3.10 Software now includes

Menu system allowing setting the

  • IF Frequency
  • IF Offset (VFO+IF, VFO-IF, IF-VF0)
  • Minimum Frequency & Maximum Frequency
  • Reference Oscillator Calibration and Factory Reset
  • Additional Band settings
Short Kit

You need to add the following items to this kit

  • The AD9850 (5 volt) module (available on eBay)
  • Two or four push-buttons
Easy assembly

All the components are mounted on a high quality double sided silk-screened fiber glass printed circuit board. Full set of instructions with circuit and wiring

Software specification
  • operating frequency range 0-40MHz in 1Hz-1MHz steps (assumes VFO+IF mode)
  • frequency setting by rotary encoder or two push buttons
  • frequency band setting by push button (LOW,160M,80M,40M,30M,20M,17M,15M,12M,10M)
  • frequency step setting by push button (1Hz,10Hz, 100Hz,1KHz,5KHz,10KHz,100KHz,1MHz)
  • full menu system for setting user defined parameters
  • IF frequency and IF offset (VFO+IF, VFO-IF, IF-VFO), minimum and maximum frequency range
  • restores last frequency, last band, last step size and all user settings, on power up
  • 32 bit arithmetic calculations for highest accuracy
  • calibration function implemented in software and factory reset
  • designed to control the 20 pin plug-in AD9850 DDS 5 Volt Modules (user supplied)
  • designed to control a 16x2 line LCD display (user supplied)
  • PIC Processor with EEPROM, software written in assembler using Microchip MPLAB
Hardware specification
  • pcb size 85mm x 40mm
  • high quality double side pcb with solder mask and silk screen
  • pre-programed PIC16F628A micro-controller
  • on-board voltage regulator for 5v plug-in module
  • input voltage 9 to 12 volts DC (polarity protected)

All specifications subject to change without notice