Antenna loading device with series connected loading coils
OwnerDonald H. Wellsinventor
Life of this patent
Estimating the term…
Abstract
A trimming device for a whip antenna, and the like, wherein two coaxial coils are connected in series with each other and with the antenna whip; and a tuning ring is positioned in the combined external magnetic field of both coils. The tuning ring, being in the external field, has an annular flow of electricity induced therein which in turn produces a magnetic field which opposes that of the coils. In the preferred arrangement, an insulating spacer sheet is wrapped over the inside coil, and the outside coil is wound tightly over the spacer sheet to provide a predetermined amount of intercapacitance between the coils, which can be changed by changing the thickness of the spacer sheet.
Claims17
A variable mutual transductance tuned circuit, and the like, comprising:
- a first helically wound coil, a second helically wound coil positioned coaxially inside of said first coil, first and second terminal elements, means seried connecting said coils to each other and to said first and second terminal elements in an electrically conductive arrangement so that the magnetic fields of both of said coils are common, are generally in phase, and add at resonance;
- an electrically conductive inductance producing tuning member positioned in the field of both of said coils and isolated from ground so that electrical flow therein produces a magnetic field which interacts with the magnetic field of both said coils;
- and means for changing the inductive interactance of said member to the combined magnetic field of said coils.
An antenna trimming device, comprising:
- a base terminal, an electrically conductive antenna rod support spaced axially from said base terminal, an inner axially extending coil positioned generally between said base terminal and said antenna rod support, an outer axially extending coil generally surrounding said inner coil, said coils being connected in series to each other and to said base terminal and antenna rod support in an electrically conductive arrangement so that the magnetic field of both said coils are common, are generally in phase, and add at resonance, an inductance producing tuning member transversely positioned in the magnetic field of both said coils and isolated from ground to product an inductance which interacts with the force of said magnetic field, and means for varying the interactance of said inductance producing tuning member with said magnetic field.
An antenna trimming device, comprising:
- a base terminal, an electrically conductive antenna rod support spaced axially from said base terminal, an inner axially extending coil positioned generally between said base terminal and said antenna rod support, an outer axially extending coil generally surrounding said inner coil, said coils being connected in series to each other and to said base terminal and antenna rod support in an electrically conductive arrangement such that the magnetic fields of both said coils are common, are generally in phase, and add at resonance, and an inductance producing trimming device positioned externally of said outer coil and isolated from ground so that its field interacts with said magnetic fields of both said inner and outer coils, and means for varying the inductive interactance of said tuning member with said magnetic field of said coils to vary the oscillating frequency of the structure to which the device is connected.
Dependencies are inferred from the claim text.