Amateur Extra › E2 Operating Procedures › E2E11
E2E11
What is the difference between direct FSK and audio FSK?
Pick an answer to check it.
Answer: A. Direct FSK modulates the transmitter VFO
Direct FSK shifts the transmitter's VFO (oscillator) frequency directly. Audio FSK instead feeds shifting audio tones into an SSB transmitter. Bandwidth and baud rate are not inherently different.
Tip: Direct FSK keys the VFO itself.