The IF is 490 kHz. I have learnt that the local oscillator and the tuning block before the IF stage must "be aware of each other" or track. So in my case, the tuning of both the circuits should differ by 490 kHz. See this article:
Specifically, it is mentioned that:
Since we have to tune the RF amplifier section throughout the entire broadcast band, the frequency of the local oscillator must also vary in a manner that it always maintains a gap of 455 kHz. To achieve this condition, the Local Oscillator and RF Amplifier section are 'ganged', i.e. their tuning condensers are connected/ganged mechanically in such a way that when we tune the variable capacitor in the RF section, the variable capacitor in the local oscillator also changes its value, it 'tracks' the frequency to which the 'Aerial Circuit' is tuned and remain separated from the tuned frequency by 455 kHz up.
I want to know how exactly is this tracking done. As far as I understand, the variable capacitor is made common to both the oscillator as well as the front end tuner. How will this lead to a difference of 455 kHz (or 490 kHz in my case) in the tuning of the tank as I vary the frequency of the oscillator?