Hi all...Suppose the driver transformer is burnt out or open on a radio using typical push/pull output tube configuration,..... and before I have it rewound, I happen to have a regular inter stage transformer 1:3 impedance ratio (instead of the usual 1:1 that driver transformers are)... that I got from Antique electronic supply....and I use it from the plate of the audio tube to the grids of the output tubes.Will this be okay or will it cause serious distortion or worse.....cccaaawwwzwhoosszzzzhzhshsh.?

If the primary impedance is a good match for the anode circuit that it is going into, the even higher secondary impedance that will be driving the grids shouldn't be a problem. However, you will likely need to add (or adjust the size of the present) resistors in series with the grids in order to keep the AC grid voltage swing in the linear region of the tube's transfer curve (to avoid overdriving and distortion). If this is a set with external grid bias, this resistor selection can be treated as the top half of a voltage divider resistor pair. If it is a self-biasing tube set (unlikely, if it uses a driver transformer), you will need two resistors to form the voltage divider: a series resistor from transformer output to grid, and a resistor from the grid to signal ground.