[Boatanchors] Audio drive needed for 813 (x 4) AM modulator

[chris at yipyap.com]

Greetings!

I'm still working on the restoration of the 1-KW AM transmitter
I inherited from the former W6MSC  (see http://www.yipyap.com).

The modulator uses four 813 tubes, two pairs each side of a push-pull.
There is an audio transformer, but no other active devices in the
audio chain before the 813s.  So I will need to provide whatever
audio drive is necessary by other means.

>From my RCA TT book, it says the grid circuit resistance is 30k ohms max.
And the peak AF grid#1-to-grid#1 voltage is around 180.  (is that the 
total swing of voltage or the positive peak?)  Assuming thats the
total swing, I'm calculating about 1.1 watts drive per tube.   I need to
have an audio amp will will put out somewhere around 5 watts.  Since
volume controls come cheap a little extra would be better, maybe 10 watts.

One line in the RCA TT book has me puzzled, it says

"Maximum-Signal Driving Power(Approx.)   0 watts."

What does that mean?

Chris
kc0atc
chris at yipyap.com