FreeDV 700D Test 2018-09-18 on 3817 kHz

Here is a decode of a short .wav recording of a FreeDV 700D mode transmission on 3817 kHz heard via the KFS webSDR http://69.27.184.62:8901/?tune=3817lsb The webSDR S meter read 9 S units.
The waterfall exhibits diagonal bands characteristic of ionospheric selective fading and multipath NVIS signal interference. At the time of this test, analog SSB voice signals also exhibited a wavering echo effect. The voice sounds distorted and robotic but somewhat intelligible with dropouts. The "KP4MD, Op Carol in Citrus Heights" text message decoded with several character errors.
The FreeDV encoded audio was piped via Virtual Audio Cable to PowerSDR.
The transmitter was a Flex-3000 driving an Elecraft KPA-500 amplifier and a Tarheel 100A-HP vertical antenna. The transmitter power was a constant 200 watts average, a significantly higher duty cycle than a corresponding analog SSB transmission.

Видео FreeDV 700D Test 2018-09-18 on 3817 kHz канала KP4MD