I'd like to build myself a small SS QRP CW TX with a broad transmit
frequency range (say 3-10 or 5-15 MHz), and clean output. Something I
could use now on the current ham bands with a CW-capable digital
portable RX, but could forget in a cupboard and use anywhere else if
the need / right arises in n year's time.

Hardwired band limits may look reassuring from a legal standpoint, yet
almost all commercial radios DO let you get into trouble, frequency
wise, so what the heck... + you don't know what the future has in
store.

I figure it would be plenty to put together the following:

- always on VFO

- a couple of quasi-linear _tuned_ (!) amp stages
built around a 3-section variable capacitor

- no bandswitching, no plug in tuning coils
or HRO-style coil drawers

- always-on buffer

- power keying on PA

- electronic QSK

- switched receive-mode VFO-offset cap,
patched it into QSK,
to kick it way off the operating frequency
( and off the _amp_chain_passband_ as well ! )
& fully kill output + avoid any issues
in isofrequency operation

- pi network, PA current meter.

I'd draw the line this side of DDS, with huff-puff to be perhaps added
at a later stage, but I'm open to convincing.

I could sure dream up a circuit, but I wonder where to look for
inspiration. I know e.g. no solid state professional transmitters of
such ilk...

1960's solid state tactical radios perhaps?

Ideas anyone?