Synthesizing a PT center tap

[sepulchre]

I have a transformer with no center tap. It's a Classictone 40-18015 - 300v, 200ma. So I'm trying to set up bias voltage. Unfortunately, using a rectifier bridge yields too much voltage; my power tubes are 5881 and even if I used other tubes the OT is only 40w. A couple of diodes would work fine for the rect. and bias voltage would be easy to rig but . . . no center tap. So, how to ground the PT?

I've poured over schematics searching for a solution with no luck. I really can't afford another transformer right now (retired, wife and I both just had surgery, etc.). Also, I've been away from amp building for awhile but retirement is finally affording me some extra time for it.

So, is there a way to derive a sort of pseudo-center tap? Or is there something else I'm missing?

[sepulchre]

Okay, I just saw that the 40-18015 has a 39v bias winding. (duh)

Problem solved.