These are high quality ferrite antenna coils. The ferrite rods are 125 ui permeability. The ferrite rods are 10mm x 60mm.

For AM Radio match the 180uh coil with the Dual Section 266pf Variable Capacitor. Use both sections of the 266pf variable capacitor for a total of 532pf. You can optionally include one or more of the trimmers to lower the frequency range slightly if needed.

These are known as Ferrite Rod Loopstick Antenna Coils used in AM radios and Crystal ( Xtal ) Radio Sets. These are also known as a Antenna Coils, Ferrite Antenna Coils, Loopstick or Loop Stick , Magnetic Antenna Coil, Ferrite Rod Antenna Coils, AM ferrite Antenna Coils, Ferrite Rod Coils. Crystal Radio Antenna Coils. Crystal Radio Coils.