Is it possible to tune IF transformers to frequency
without having them in a set? I seem to recall that it can be done with a sig generator somehow.
Also, I would like to retune small top and bottom slug tuned 10.7MC IF cans down to 9MC. What suggested capacitance in parallel with the existing internal caps would do the trick?

:
:Is it possible to tune IF transformers to frequency
:without having them in a set? I seem to recall that it can be done with a sig generator somehow.
:Also, I would like to retune small top and bottom slug tuned 10.7MC IF cans down to 9MC. What suggested capacitance in parallel with the existing internal caps would do the trick

You can use a grid dip meter to tune the IFs, but adjusting them while outside of a radio would not do much good (IMO) because the circuit will change the frequency response. I doubt if a 10.7mHz IF transformer can be lowered to 9mHz easily; this is quite a drop.

I have done this bench tweak-test easily.
Just feed 455khz to one winding with my scope across the other winding. Then tweak for max.
Then reverse it with the other winding.

But when returning the IF to the circuit you'll still need a bit of re-tweaking as things change when in-circuit.

Agreed... that the "pretuning" of the IF 's would DEFINITELY be more problematic at 10.7 mhz versus the lower 455kc spectrum, with the inherent
proportionate change in added circuit, stray and distributive capacitance at the higher frequencies.



"""""Also, I would like to retune small top and bottom slug tuned 10.7MC IF cans down to 9MC. What suggested capacitance in parallel with the
existing internal caps would do the trick """"""

Give me the existant pri and sec tuning cap values ....(if of different values)..... and I will come back with the additional capacitance required.

73's de Edd

:
:Is it possible to tune IF transformers to frequency
:without having them in a set? I seem to recall that it can be done with a sig generator somehow.
:Also, I would like to retune small top and bottom slug tuned 10.7MC IF cans down to 9MC. What suggested capacitance in parallel with the existing internal caps would do the trick?