[Boatanchors] Push-pull tank circuit

[Barrie Smith]

I've got a couple of questions regarding push-pull tank circuits.

The first is concerning bypassing the rotor (for RF) to ground.  This is supposed to increase the voltage capability of the tank capacitor.  However, in any of my handbooks, I do not see an amount given.

I'm working on a rig right now for just 10 and 15M, AM.  The tank capacitor "should" (according to the handbooks) be okay for 2000 volts DC.

If the rotor was bypassed to ground, what increase could I expect?  

Also, in some schematics for push-pull, I see the B+ connected to the center of the tank coil.  In other circuits I see the B+ connected to the center of the tank coil and also connected to the rotor of the capacitor through a 35K resistor, or a choke.

What's the difference between these three methods?

Retired minds want to know.

73, Barrie, W7ALW