US3487415A

US3487415A - Combination uhf-vhf television receiving antenna

Info

Publication number: US3487415A
Application number: US644019A
Authority: US
Inventors: Sylvan Simons
Original assignee: Individual
Current assignee: Individual
Priority date: 1967-06-06
Filing date: 1967-06-06
Publication date: 1969-12-30
Anticipated expiration: 1986-12-30

Description

1969 s. SIMONS 3,487,415

COMBINATION UHF-VHF TELEVISION RECEIVING ANTENNA I Filed June 6, 1967 INVENTOR. Flg. 3 .SYLVAN SIMONS ATTORNEY United States Patent Office Patented Dec. 30, 1969 3,487,415 COMBINATION UHF-VHF TELEVISION RECEIVING ANTENNA Sylvan Simons, Angelus Drive, Glenville, Conn. 06830 Filed June 6, 1967, Ser. No. 644,019 Int. Cl. H01q 21/12 US. Cl. 343-814 7 Claims ABSTRACT OF THE DISCLOSURE The design of any combined UHF and VHF TV receiving antenna is complex because of the Wide range of frequencies to be covered. The low band VHF is from 54 mHz. to 88 mHz. The high band VHF is in the range from 174 mHz. to 216 mHz. On the other hand, the UHF channels operate from 470 mHz. to 890 mHz.

It is an object of the present invention to construct a TV receiving antenna that operates efficiently in both the VHF and UHF bands yet is small in size for decreased wind resistance, and is consequently economical to manufacture.

Another object of the present invention is the construction of a tapered UHF unit consisting of wire elements which thereby effectively cover the full UHF band.

A further object of the present invention is to provide adjustment features on the antenna to ensure the best possible reception on both VHF and UHF channels.

The above and other features, objects and advantages of the present invention will be fully understood from the following description considered in connection with the accompanying illustrative drawings.

FIG. 1 is a perspective view of my combined VHF-UHF television receiving antenna constructed in accordance with the teachings of the present invention.

FIG. 2 is a perspective view of one of UHF wire elements disclosing the movement of the wire element from the extended position to the folded-back position.

FIG. 3 is a perspective view of a modification of the TV receiving antenna illustrated in FIG. 1.

FIG. 4 is a front elevational view of the antenna illustrated in FIG. 1.

Referring to the drawings, the present television receiving antenna comprises a vertical mast upon which is mounted a horizontal boom 12. Both the mast and the boom are preferably constructed of aluminum tubing. A U-bolt clamping bracket assembly 14 rigidly fixes the boom 12 to the mast 10. Secured to the boom 12 is a low band VHF folded dipole 16 and spaced therefrom a high band folded dipole 18. Both

dipoles

16 and 18 are supported on one side of the boom 12 by means of

metal brackets

24 and 26 respectively. In addition, both

dipoles

16 and 18 are further supported and insulated from the other side of the boom 12 by means of insulators 20 and 22 respectively.

Connectors

28 and 30 are parallelspaced and connect the low band VHF dipole 16 with the high band VHF dipole 18.

Directors

32 and 34 mounted forward of dipole 18 are supported by

metal brackets

36 and 38 respectively. In addition, low band VHF reflector 40 is supported on the boom 12 by a metal bracket 42 while high band VHF reflector 44 is supported on the boom 12 by metal bracket 46.

It should be noted that

conductors

48 and 50 are extensions of

connectors

28 and 30 and project forwardly toward the front of the antenna.

The dipoles, reflectors, directors, connectors and conductors are preferably constructed of aluminum tubing of between inch and /2 inch outside diameter.

Mounted on the parallel-spaced

conductors

48 and 50 are UHF elements 51 through 60 respectively which are preferably constructed of inch diameter aluminum wire. The UHF elements are tapered from the front to the rear to thereby ensure full coverage of the UHF band. The five UHF dipoles are resonant at various points on the UHF band. This staggered tuning permits the UHF system to respond efliciently to all the channels in the UHF frequency range of 470 mHz. to 890 mHz. FIG. 2 discloses a UHF Wire element in its normal extended position whereby it is seated in the spring-like split bracket 62. The UHF wire element 60 may be folded back to the position A, as shown in dotted lines in FIG. 2, for shipping purposes.

The lead-in wire W connects into the antenna at the insulated bracket 20 at the junction of the low band VHF dipole 16 and the

connectors

28 and 30.

It should be noted that the present novel combination UHF and VHF TV receiving antenna operates effectively on all bands. Thus, when operating on the low VHF band, the high VI-[F band dipole 18 together with the

connectors

28 and 30 add up to an equal A wavelength resonant section of short circuited transmission line which has the characteristic of exhibiting a high impedance at its open end. Therefore, the high band VHF dipole 18 will have a negligible loading effect on the operative low band VHF dipole 16, the latter intercepting the signal. Moreover, any reactance introduced by

conductors

48 and 50 together with the UHF elements 51-60 can be compensated for by adjusting the lengths of

connectors

28 and 30 by means of movement of the positions of the high band dipole 18. Low band directivity and gain is enhanced by means of reflector 40.

When operating on the high

VHF band connectors

28 and 30 are wavelength long and make the low VHF band dipole 16 appear at 18 as a high impedance because of the inverting properties of the A wavelength section constituted of

connectors

28 and 30. Similarly, the low VHF band dipole 16 together with the

connectors

28 and 30 may be adjusted in length to provide the optimum impedance across 18 to enhance the performance at the high VHF band. 'Ihus,

conductors

48 and 50 together with the reactance of UHF elements 5160 are of such a length as to simulate a wavelength open section of transmission line and will therefore exhibit high impedance at 18 to thereby result in negligible loading effects. Furthermore, any undesirable reactance can be compensated for by a slight readjustment of

connectors

28 and 30. In addition, high band directivity and gain are further increased by utilizing

directors

32 and 34 and reflector 44.

When operating at UHF frequencies the VHF dipoles will be far removed from their resonance point and therefore will have a minimum loading effect on the UHF system. Moreover, any reactance encountered can be compensated for by the adjustment of

conductors

48 and 50 as well as

UHF dipole elements

59 and 60. In addition, it should be pointed out that the high VHF folded dipole 18 functions as a reflector for the UHF section thereby resulting in maximum high gain on all UHF channels.

A television antenna constructed in accordance with the teachings of this invention has the following dimensions:

UHF elements: Inches 51 and 52 /2 53 and 54 4% 55 and 56 4 57 and 58 3 /2 59 and 60 3 High band directors 32 and 34 (end to end) High band dipole 18 (end to end) 29 Low band dipole 16 (end to end) 80 High band reflector 44 (end to end) 33 /2 Low band reflector 40 (end to end) 109 Distance from low band reflector 40 to high band reflector 44 22 Distance from high band reflector 44 to low band dipole 16 11 Distance from: low band dipole 16 to high band dipole 18 12 Distance from high band dipole 18 to first director 34 6 Distance from first director 34 to second director 32 6 Distance from high band VHF dipole 18 to UHF elements 51 and 52 6 Distance from UHF elements 51 and 52 to UHF elements 53 and 5,4 4 /2 Distance from

UHF elements

53 and 54 to

UHF elements

55 and 56 4 Distance from

UHF elements

55 and 56 to

UHF elements

57 and 58 Distance from

UHF elements

57 and 58 to

UHF elements

59 and 60 3 FIG. 3 illustrates an alternate embodiment of the present invention in which the UHF elements 51-60 are mounted on the connectors 28 and and thereby reduce the overall length of the antenna. The

directors

32 and 34, however, remain in the same relative positions on the antenna assembly.

I claim:

1. An antenna for receiving television signals on both VHF bands and UHF bands comprising a dipole driven element for receiving the low frequency VHF television band and another spaced dipole driven element for receiving the high frequency VHF television band, a pair of spaced connectors connecting said driven dipoles, said spaced connectors being about wavelength long at said high frequency VHF television band, a pair of spaced conductors being forward extensions of said connectors in front of said dipole for the high frequency television band, and a plurality of UHF dipoles mounted on said spaced conductors, said conductors together with said UHF dipoles being resonant as a wavelength transmission line at the high frequency VHF television band.

2. An antenna for receiving television signals on both VHF bands and UHF I bands as set forth in claim 1 wherein said dipole driven elements are folded dipoles, and said folded dipole for receiving said high frequency VHF television band functions as a reflector for said UHF dipoles.

3. An antenna for receiving television signals on both VHF bands and UHF bands as claimed in claim 1 wherein the lengths of said connectors may be changed to overcome any reactance introduced into the antenna by said conductors and UHF dipoles when operating on the the antenna at the high VHF television band.

4. An antenna for receiving television signals on both VHF and UHF bands as claimed in claim 1 wherein said low band VHF dipole and said connectors may be changed in length to provide the proper impedance value in the antenna and thereby enhance the performance of the high VHF television band.

5. An antenna for receiving television signals on both VHF and UHF bands as set forth in claim 1 wherein when operating at said UHF band any reactance therein can be compensated for by adjustment of the length of said conductors and at least two UHF dipole elements.

6. An antenna for receiving television signals on both VHF and UHF bands as set forth in claim 1 wherein said UHF system is constituted of a plurality of spaced dipoles arranged in a tapered pattern which are resonant at various points of the UHF band whereby said plurality of spaced dipoles respond efliciently to all the channels in said UHF system.

7. An antenna for receiving television signals on both VHF bands and UHF bands comprising a dipole driven element for receiving the low frequency VHF television band and another spaced dipole driven element for receiving the high frequency VHF television band, a pair of spaced connectors connecting said driven dipoles, said spaced connectors being about A wavelength long at said high frequency VHF television band, a plurality of UHF dipoles arranged in a tapered pattern mounted on said spaced connectors between said dipole for receiving the low frequency VHF television band and said dipole for receiving said high frequency VHF television band.

References Cited UNITED STATES PATENTS 2,975,423 3/1961 Wells 343817 ELI LIEBERMAN, Primar Examiner US. Cl. X.R. 3438 15