USB wobbler

The wobbler is a very useful tools for LC filter alignment or ampilifier's transmission characteristic measurement.
The hearth of my first wobbler generator is an AD9851 dds chip handled by PIC18F2550 usb mcu.
The maximum frequency of the wobbler is about 80 MHz. It is enough to the most of short wave projects.
The DDS chip followed by a low-pass filter then the signal is amplified with a MAR-3 monolit amplifier chip.
The output level can be vary with a two-stage attenuator.
The input sensor is a high dynamic range AD8307 chip.
I wrote a software in LabWindows CVI to display the measured results.