PC Controlled AD9850/1 DDS Rx

Wobbler is easy to use as a simple PC controlled VFO for (ham)radio transceiver/receiver. To provide this service a simple program for Microsoft Windows platform was created. It is program, which controls an AD9850/1 DDS unit as VFO.

From the wobbler hardware, of course, the whole AD part can be omitted.

All important things are described in wobbler help and description. This description deals only with control program features.

Band switching is allowed provided they are swithed by relays. Interface is not descrivbed here. PTT (Rx/Tx switching) is also outputed to LPT port. Port pins assignment is described in the program help.

Main Screen
rx.png, 9 kB

contains 5 fields:

  1. working frequency display
  2. HAM radio band selector,
  3. 4 memory controls,
  4. tuning controls,
  5. program controls.

Working frequency is NOT measured, but programmatically set value (control word sent to DDS). Real accuracy depends on DDS clock accuracy.

Memory controls contain doubles of buttons:

  • R means "read memory and set it as working frequency"
  • W means "save current working frequency to memory"

Tuning is possible by clicking to 4 buttons:

  • "<<"
  • decreases working frequency by 1 kHz,
  • "<"
  • decreases working frequency by 10 Hz,
  • ">"
  • increases working frequency by 10 Hz,
  • ">>"
  • increases working frequency by 1 kHz,
The same function, but with autorepeat, have 4 keyboard keys - M, ,, .and / - in the right bottom keyboard corner.

Rx/Tx switching is done by SPACE button.

Program controls have the following functions:

  • Help - openes this description,
  • About - openes info window with my contact information,
  • Setup - openes program configuration window,
  • Close - closes program.

Setup Window
setup.png, 12 kB

contains all important information:

  • 9 bands - minimum and maximum frequency in MHz
  • parallel port for DDS communication
  • DDS clock in MHz and its multiplication factor
  • intermediate frequency of the receiver in MHz

The only difference between Save and Close buttons is, that Save button saves the changes into rx.ini file, while Close button not.

All information, together with content of memories, is saved to the textual file rx.ini. This file is updated if:

  • Save - button is clicked
  • programs finishes by clicking on main screen Close button
  • clicking W button of any memory

If rx.ini file doesn't exist program creates standard one. This file can be modified using Notepad or similar text editor, provided enough skill, of course.

Program requires: