"Tim Wescott" wrote in message
news
Ross, NS7F wrote:
In a circuit with two 6.3V tubes, can I just series the filaments so
that I can use a 12-13.8V supply? Or are there subtleties that I'm
missing?
Thanks,
Ross NS7F


* some tubes take longer to warm up than others. When they started
putting color TV's together with long strings of filaments that added up
to 110V, they also instituted "controlled warm-up" filaments so they'd all
warm up in about the same amount of time. I don't know if this is such a
big deal at 12V.

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com


A suffix tubes I believe will work in series string (providing the
filament currents are the same that is..).

Pete