[Radio Wrangler]

2k and a 10:1 turns ratio gives 200k Ohms impedance on the full winding section. For a transformer, you want Zl to be at least a few times this, say 600k minimum At 455kHz that's 209mH and would resonate with 0.58pF so you won't be able to do this without self resonance problems.

The only escape is to accept that there will be resonance and abandon the idea of an untuned transformer. You can now use lower L values, the strays would push the SRF up above the target frequency, but then you need more C to resonate the transformer, and that C can gobble up the stray.

Remember that crystal, ceramic and mechanical filters all have various stray responses, so some LC selectivity helps cover them.

David