Created: Feb, 6 2006
Over the years I have wound and experimented with Hundreds of coils. Many Varied Sizes and Shape. Considerably interesting are the Small coils wound on Ferrite cores.
1) Is a PQ Core, Custom made Delrin Bobbin. Outside Diameter of this Bobbin is 1.25 inches. "Fair-Rite" Core, Part Number "6677404021". This coil has an Inductance of 312.6 uH. Free Air Resonance Measures 2.06 Mhz. The Internal Capacitance calculates to be 19 pF. Characterics: Especially Uni-Directional with pickup at dead center. 2) Is a Pot Core, Custom made PVC Plastic Bobbin. "Fair-Rite" Core, Part Number "5677362221". Coil Inductance is 129.4 uH. Free Air Resonance is 6.99 Mhz. Internal Capacitance is 4 pF. Characterics: Also Especially Uni-Directional, but not as sensitive as #1. 3) Is a U Core, Custom made Delrin Bobbin. "Fair-Rite" Core, Part Number "9277015002". In Phase Coil Inductance is 323.8 uH. Free Air Resonance is 2.11 Mhz. Internal Capacitance is 17.5 pF. Characterics: Considerably Uni-Directional. Most Sensitive at Either Pole. 4) Is a Ferrite Rod, The Coil is wound on a Custom made ABS plasic Bobbin. The Total Length of this, Including Bobbin is 2.25 inches. The Fair-Rite Rod is Part Number "4077375211" (3/8" Diameter X 1 15/16" Long) Coil Inductance is 300.4 uH. Free Air Resonance is 1.750 Mhz. Internal Capacitance is 27.5 pF. Characterics: Not Very Directional, but somewhat stronger to the ends than the sides.
Some of the Ferrite Coils I have made for my Detector.
Number 1 is by Far the best, Excellent for Pin-Pointing and detecting Small objects.
"Back to My HOME Page"
Copyright © Feb 2006