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

Hey JB
I assumed since the query was in this group it wouldn't be a FT-1000 and
not an AA5 because it has only one IF. It would be nice to know what
radio but anxious people making queries and get carried away and I'm
one..
Hank

I hear ya! Most of these discussions leave the tracks in a hurry and wind
up out in the cornfield.

We don't know if a bfo or product detector or regen or filters or a
converter stage involved. Everybody else seems to have thrown the book at
him.

"Henry Kolesnik" wrote in message
...
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.

Thats fine for untuned transformers, but surely in the case of these I.F.
transformers that consist of mutually coupled parallel tuned circuits, this
must be different?

A tuned circuit is a reactive load just like an untuned circuit except
its reactance is max at the desired frequency. Any DC resistance such
as the diode and it's load are undesirable as they lower Q.

--
73
Hank WD5JFR
"Theo" wrote in message
...

"Henry Kolesnik" wrote in message
...
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.

Thats fine for untuned transformers, but surely in the case of these
I.F. transformers that consist of mutually coupled parallel tuned
circuits, this must be different?