[exray]

This comesd up once a month or so here and elsewhere. Onc upon a time there were navigational beacons close to 455 KC which would interfere with radio reception. No longer an issue.

But this component has nothing to do with that. It uses a series-resonant 'wavetrap' configuration for improved bypassing at the IF frequency. Wavetraps to minimize beacon interference are located at the antenna input. Philco should have used a better term to avoid confusion.
Aerovox (and others) also made them without the need for the external winding and sold them as "resonant capacitors".