"SpamHog" wrote in message
oups.com...
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?


Hello,

Try to get hold of an HW8, an old Heathkit QRP CW Transceiver.

Lots of modifications and/or extensions can be found on the internet.

Use an old RC4 (Drake) for listening. With some effort, you can let those
two rigs transceive.

Plenty of projects around that idea!

Have fun.