[R-390] Z503 and ALL IF 455Kc coils

[rbethman]

Here is the quote drawn from the cost reduction analysis report:

    2.3.7 Part 7 - RF Coils
    Experimentation was started on the 16-32 mc band RF coil to improve its
    tracking. A considerable improvement resulted from changing the
    length to
    diameter ratio and using a smaller diameter coil. As soon as the
    design was
    complete steps were taken to put this coil in production receivers.
    Later work
    showed that similar results could be obtained using the larger coil
    diameter
    with a ferrite core to replace the powdered iron slug. All the RF
    coils have
    since been redesigned to use the same ferrite core. These new coils
    also have
    a higher Q than those in the current R-390. The variable IF coils
    have also
    been redesigned to use a common core. This core however differs from
    that used
    in RF coils, because a lower permeability higher Q core was needed. Coil
    frames have been redesigned for simpler assembly, and teflon
    terminals are
    used to maintain high circuit Q. Antenna links have also been
    redesigned to
    attain a more uniform antenna input impedance.

So, it CAN be determined that the IF Coils *WERE* given specific designs.

I do not doubt that one or another proposed solutions "could" be used.  
However, particular attention was paid to this area.  The same was true 
of the mechanical filters versus the R-290/URR L/C filters.

To each his own!  I'll be replacing *MINE* with a like part.

Sources for components AND radios has been made.

Bob - N0DGN