Basic Qualification · B-003 Station assembly, practice and safety · B-003-011-002
What can be done to keep a CW transmitter from chirping?
- A Add a low-pass filter
- B Keep the power supply voltages very steady under varying loads
- C Add a key click filter
- D Keep the oscillator impedance very steady under the transmit load
Correct answer: B — Keep the power supply voltages very steady under varying loads. From the official ISED question bank, verified word for word.
Why
Chirping happens when a CW transmitter's pitch wavers slightly each time the key is pressed, usually because the power supply voltage drops momentarily under the sudden load of transmission. The full explanation — and one for every question — is in Pro.
Practise this section
Building a station safely: power supplies, grounding, RF exposure, lightning, feedline routing, and what a transmitter, receiver and transceiver actually do.