As long as we are speculating, how about a hybrid? A tube transceiver that uses a solid state VFO (for stability) (or at least a VXO). It's been done before (lots of times).
Here's a hair-brained idea: A solid state transceiver with one tube there just for effect. The filament could light with the 12 volt supply but not do anything other than drain the battery faster and maybe provide enough light to see your logbook (and keep your hands warm). When operating in the field, the tube could be removed to conserve power. OK, I'll get back under my rock...
Don't forget that this coming Sunday from 7:00-9:00 pm (CST) is the January Second Sunday Sprint. Rules are on the 4SQRP website, under "operating activities".
I'm having some major construction done here at the house but hope to be able to tabulate the results as usual next week, assuming all the fillings haven't rattled out of my teeth by then!
72 and happy belated New Year,
4SQRP Contest Coordinator