Mike, The center tap may not be for the oscillator. For instance in the 39/49/59's the ferrite bar has 5 leads as well. Two connect the short coil to the long coil in series. Two leads are the far ends of the connected coils and these go across the variable capacitor. I assume the M37 is varcator diode driven to introduce capacitance. The smaller coil is moved along the ferrite bar to fine tune inductance for proper matching to ensure tracking. The tapped lead is most likely there to keep signal load down and goes directly to AM RF pin. ( Until I hear a better theory. Transformer for impedance match?). In the analogs above, the Oscillator coil is an IF can, L3.
73 Gil _______________________________________________ IRCA mailing list [email protected] http://montreal.kotalampi.com/mailman/listinfo/irca Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers For more information: http://www.ircaonline.org To Post a message: [email protected]
