On Sat, 9 Aug 2008, Antonio Vernucci wrote:

I'd like to hear someone having tried to use a power transformer as output
transformer for the single-ended final stage of a tube communications
receiver (power 5W, maximum, frequency not higher than 4,500 Hz).

I haven't done it, but it was a pretty common trick to see in the
magazines in the old days.

At least one article pointed out that if you started with a 400Hz
transformer, which were common in surplus from aircraft, you'd likely
get better frequency response where you needed it.

Michael VE2BVW