Finally got around to a Sentinel farm radio I found a while back. Initially powered it with 10 9volt batteries for the B+ and a C cell for the filaments. This worked pretty well.

Now I'm using an AC adapter I built from plans I found online. A lot easier than all those batteries!

Seems like a pretty good set for it's day. It's easy on the batteries drawing 200ma on filaments and 6ma on the B+.

The set come on almost instantly I guess those 1.5v filaments don't take long to heat up.

I have a few portable tube types with the 1v tubes and never thought about putting 9 volts in series. 200ma would eat a c cell up pretty fast. They make some 8 amp rechargeable D cells that would be pretty cool for this.