You should look at the 866 datasheet and draw out the complete circuit properly.
Transformer to heat you seem to have got right.
Then you need an AC source and a load. Hookup like datasheet.
Cook for 40mins first time out with filaments on only. Then if used evey day or so, about 1 min heat before HT. A 200mA current through them is a good full glow.
I used them for about 20 years in power amp, smaller ones in phono for similar time. They look great and I liked the sound. Had a decent stash but as I needed to make my power amps very compact (relatively) I couldn't give them the spacing required so went TV dampers and DHT rectifier (respectively) for no real loss of sound quality.
As long as your reasonably careful, it's no less safe than walking out your front door.
Transformer to heat you seem to have got right.
Then you need an AC source and a load. Hookup like datasheet.
Cook for 40mins first time out with filaments on only. Then if used evey day or so, about 1 min heat before HT. A 200mA current through them is a good full glow.
I used them for about 20 years in power amp, smaller ones in phono for similar time. They look great and I liked the sound. Had a decent stash but as I needed to make my power amps very compact (relatively) I couldn't give them the spacing required so went TV dampers and DHT rectifier (respectively) for no real loss of sound quality.
As long as your reasonably careful, it's no less safe than walking out your front door.