Hate to tell you this, but with many classic few-tube transmitters you
get your choice: either chirp or clicking or chirp and click.

If you key the oscillator, you get chirp.

If you keep the oscillator running all the time and key the
driver/final, then you get clicks. Not to mention some backwave
(leakage of carrier when you are key-up, leakage is almost inevitable
in a tube oscillator where you running the oscillator at 10 or 20V
P-P.) Without enough buffering you also get chirps as the keying of the
later stages loads down the oscillator stage.

A 50's or 60's ARRL Handbook will have a chapter about the tradeoffs in
keying methods. Many 4 or 5-tube transmitters, despite all their
buffering and keying stages and VR tube, still have noticable
chirp/click and while you should certainly strive to understand the
issue, you will have some chirp with any simplistic TX. In terms of not
interfering with QSO's up and down the band, some chirp is preferable
to some click.

Tim.