RCA Ba6a Innerstage XFMR

[CJ]

Nice work!

What kind if AC voltages does that inner stage PRI see at normal operating levels?
Sowter probably uses an EI core with a larger cross section , this means less turns needed to get the equivalent Henrys as the original . Less turns means less effect from DC imbalance as the H field for DC is a function of Ampere Turns.

 

[vinyvamos]

Cheers CJ. I will measure those voltages next time I am at the test setup. From the dimensions and drawings given on the Sowter website they seem to be using an EI42 lam (or an imperial lam close to that) with a square stack height of 14mm which gives a core cross section of about 2sq.cm. The L lams however with their deep stack in the BA6 give a cross section of about 3.5sq.cm.

Agreed that less turns will have less issues with DC imbalance.

I will soon be getting hold of a Sowter 9830 so then I can put it through it's paces.

 

[CJ]

DC flux is a function of H and the Magnetic Path Length.

The RCA L lam has a MPL of 6 inches,

The EI 42 metric has about 3.5 inches,

So DC imbalance flux will probably come out equal for RCA and Sowter as twice the turns and 6" = half the turns and 3.5".