Frequency adjustable mobile antenna

A frequency adjustable antenna for transceivers operable at different radio frequencies comprising;

• a. a lower electrically conductive base mast section with a radio frequency connection thereto,
• b. an upper electrically conductive extensible mast section insulated electrically from said base mast section and adapted to hold in electrical contact therewith an elongated conductive whip,
• c. an elongated hollow cylindrical housing made of an electrically non-conductive material,
• d. an electrically conductive loading coil housed within said housing comprised of spaced convolutions and electricity connected to said lower base mast section, and
• e. contactor means carried by and electrically connected to said upper mast section for commutation with said spaced coil convolutions, said contactor means comprising a disk of electrically conductive material affixed to said upper electrically conductive mast section, said disk having protruding radially outwardly thereof a circumferential spring member comprised of a pair of axially spaced apart circumferential supporting band members having disposed axially therebetween a plurality of circumferentially spaced apart, adjacent arched tabs resiliently biased radially outwardly to contact a substantial sector of at least one coil convolution.

A frequency adjustable antenna for transceivers operable at different radio frequencies comprising;

• a. a lower electrically conductive base mast section with a radio frequency connection thereto,
• b. an upper electrically conductive extensible mast section insulated electrically from said base mast section and adapted to hold in electrical contact therewith an elongated conductive whip,
• c. an elongated hollow cylindrical housing made of an electrically non-conductive material,
• d. an electrically conductive loading coil housed within said housing comprised of spaced convolutions and electricity connected to said lower base mast section, and
• e. contactor means comprised of a disk of electrically conductive material electrically conductively coupled to said upper electrically conductive mast section, said disk having affixed thereto an electrically conductive circumferential spring member comprised of a single longitudinally elongated rectangularly shaped strip of resilient conductive material, upper and lower longitudinal edges of which are bent rearwardly from a front, outer surface of said strip and thence axially inwardly towards a longitudinal center line of said strip to form two axially spaced apart, rear, inner longitudinally disposed supporting band members, the outer, front surface of said strip continuous with said supporting band members formed into an arcuately curved, convex arched surface segmented by a plurality of transversely disposed slits spaced apart at regular longitudinal intervals into a plurality of longitudinally spaced apart arched tabs, said strip being bent into a ring-shaped loop having an axially disposed curvature axis coaxial with said disk to thereby arrange said tabs into a circumferential array having convex outer surfaces resiliently biased radially outwardly to contact a substantial sector of at least one coil convolution.

A frequency adjustable antenna for transceivers operable at different radio frequencies comprising:

• g. a lower electrically conductive base mast section with a radio frequency connection thereto,
• h. an upper electrically conductive extensible mast section insulated electrically from said base mast section and adapted to hold in electrical contact therewith an elongated conductive whip,
• i. an elongated hollow cylindrical housing made of an electrically non-conductive material and having formed in an inner cylindrical wall surface thereof a longitudinally disposed helical groove,
• j. an electrically conductive loading coil comprised of a conductor formed into spaced convolutions comprising a helix of the same pitch as said helical groove in said housing, and fitting within said groove with an inner cylindrical surface of said helix located radially inward of said inner cylindrical wall surface of said housing,
• k. a contactor means carried by and electrically connected to said upper mast section for commutation with said spaced coil convolutions, said contactor means comprising a disk of electrically conductive material electrically conductively coupled to said upper electrically conductive mast section, said disk having affixed thereto an electrically conductive circumferential spring member comprised of a single longitudinally elongated rectangularly shaped strip of resilient conductive material, upper and lower longitudinal edges of which are bent rearwardly from a front, outer surface of said strip and thence axially inwardly towards a longitudinal center line of said strip to form two axially spaced apart, rear, inner longitudinally disposed supporting band members, the outer, front surface of said strip continuous with said supporting band members formed into an arcuately curved, convex arched surface segmented by a plurality of transversely disposed slits spaced apart at regular longitudinal intervals into a plurality longitudinally spaced apart arched tabs, said strip being bent into a ring-shaped loop having an axially disposed curvature axis coaxial with said disk to thereby arrange said tabs into a circumferential array having convex outer surfaces resiliently biased radially outwardly to contact a substantial sector of at least one coil convolution, and
• l. elevator means for raising and lowering said extensible mast section and said contactor means for selective commutation with said coil convolutions, thereby increasing and decreasing the tuned frequency length of the combined coil and two mast sections.