No, not another dreaded plate curve sheet from me ;-)

Instead, get this Marconi PL83 data sheet from Frank
Philipse's site:

http://frank.pocnet.net/sheets/126/n/N309.pdf

As I see it, this noval based pentode intended for
video outputs is very linear in pentode mode and
when being triode strapped, too. See the Marconi
sheet, page 8, for the trioded data.

Moreover, the 300mA heater versions PL83/15A6 are plenty
and cheap as dirt at least here in Germany. Might be
very worthwhile to invest a few cents in that tube
and an LM317 for the heater CCS and have a try at it :-)

Tom

--
this is my favourite sig, since there is no reference to
Kibo, Discordianism or The Church of the Subgenius in it.