Colin
Good on yah mate..
Now to express it another way the winding ratio of the diode transformer
has to be such that when it reflects the diode and its load to the plate
of the last IF, the plate circuit will see the correct impedance for the
IF tube load. Transformers don't have impedance, only turns ratio to
reflect back whatever impedance they see in accordance with the turns
ratio.

--
73
Hank WD5JFR
"COLIN LAMB" wrote in message
m...
"Time to stop rambling and ask if the ARRL article distinguished the
IF transformers with different part numbers?"

Yes

The first and second stage transformers are designated "456 kc
interstage if transformer, permeability-tuned (Millen 64456)". The
third if transformer (to the diode detector) is designated "456 kc
diode transformer, permeability-tuned (Millen 65454)".

The schematic drawing for all three transformers are the same, but the
secondary of the last transformer would be different to attain a lower
impedance.

73, Colin K7FM