I am trying to use a local oscillator board from an old Motorola UHF
FM radio as part of a microwave construction project. I need to know
the input impedance of the multiplier chain so I can design a new
crystal oscillator/buffer. The original crystal frequency is in the
18 MHz region but the input coils on the board tune at around 54 MHz
so obviously there is a tripler inside the channel element.

Does anyone understand how Motorola did these things ? The original
channel element is a TLN 8968A - anyone got a schematic ?

73,
Steve VE3SMA