At left, the 136 kHz source is where long wire antenna connection would be. Two closed SPST switches is output to rest of set.
The two iron core 700 uH coils are both adjustable inductors.
Where MOSFET is should be JFET BF245 or SMT BF545.
More information at:
http://www.qsl.net/ik2pii/lf/prea136.htm
