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The first circuit is a RF amplifier, its output is tuned to a frequency set by C' and L.
The second circuit is a self oscillating mixer as found in the front end of a AM radio. L' and C4,C5,C6 tune the oscillator. C and L tune the IF transformer.
Third circuit, T2 seems to be an oscillator and T1 an amplifier, beats me whats its all about.