Connect screen to plate of the 47 together and use as plate of the 45. Yes, 47 requires less negative grid bias than 45 but this is somewhat self correcting.
Negative bias is usually generated by tubes drawing current. Since bias will be higher than usual 47's won't be drawing as much current in turn reducing negative bias.
Although I didn't find characteristics for 47 tiode connected tubes require more negative bias operated this way.
You could use other, less expensive tubes. Metal 1619's work, also 5A6's.
Norm
:Just wondering how you would change #45 tubes to #47.Push Pull... Change socket of course ...Do you just attach screen and plate together...slight rebiasing?
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