DDS Based AM Exciter
- Accurate and stable DDS oscillator, based on the AD9851 from Analog Devices Inc.
- Direct amplitude modulation of the DDS’s DAC with mod and carrier level control
- Low noise, high dynamics Norton type preamplifier
- Highly linear Class A Push-Pull final
- 10W peak / 2.5W carrier (capable of 16 W peak / 4W carrier)
- PA overcurrent protection
The exciter is at a prototype / proof of concept stage. Control, protection and boxing is yet to come, although it’s developed and being prepared. On the following shots you can see the output signal at 16 W peak power into 50 ohms and the workbench setup for the test. The unit is modulated with a GN-4 audio lab generator.