[morzh]

OK, well,

This seems like a wave trap and is not even important. You could simply remove it.
As for the value of the cap:

Let's assume 2cm diameter (if it is 2uF, it is large), and 1cm the length of the winding.
We will also assume air core.
It is just the first order calcs:

The inductance is:

Mu-zero (air dielectric const) * A (area) * N-square (turns) / l (length)

L = 4*3.14 * 10^-7 * 49 * 3.14 * 10^-4 = 2uH

Now the resonant frequency for 2uF is:

1/ (2 * Pi * SQRT (LC)) = 1/(6.28 * SQRT (0.000002 * 0.000002)) = 79 kHz.

For 0.2uF:

We will also assume the cap is 1/2 the other one's diameter, which will decrease L by 4.
But in the Frequency it is SQRT, so it is factor of 2.

So it is 500kHz.

It is pretty close to 455 kHz IF frequency.


So, my vote is for 0.2uF.


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And, again - this is not important. This LC could be removed.