US2559148A - Television antenna - Google Patents

Description

July 3, 1951 M. D. ERCOLINO TELEVISION ANTENNA 3 Sheets-Sheet 1 Filed May 23, 1950 INVENTOR rool ina w/ ///////////////////////////A J ATTORNEYS July 3, 195] M. D. ERCOLINO TELEVISION ANTENNA 5 Sheets-Sheet 3 Filed May 23, 1950 INVENTOR Mfifrcalno BY W ATTORNEYS` Patented July 3, 1951 UNITED STATES PATENT *OFFICE 3 Claims.

This invention relates to television antennas and more particularly an antenn-a of stacked conical Construction having closed-ended dipoles with a refiector spaced therefrom and supported by a, frame structure having a, pair of horizont-al Wooden spacers.

Antenna systems having stacked dipoles are relatively well known in the art. such antennas have been developed to provide high gain perforrnances in receiving high frequency electromagnetic waves throughout all the designated television Channels extending from 54 to 216 megacycles. These antennas are necessarily highly directive and are usually mounted high above the ground and on the exterior of a building or a like support means. Being thusly exposed to the elements and situated where any physical failure thereof might easily cause serious damage to property or persons it is. necessary that such an antenna be not only substantially built with a high safety factor but also securely fixed in place in order to withstand unusual wind velocities and other adverse Weather conditions. These physical requirements result in not only costly Construction but also costly installation procedure requiring the services of a service crew of skilled. television technicians for its installation and fixed orientation as to the diierent station locations for attainment of the best possible signal from each station with acceptable discrimination, or any reorientating as required. It is also well known that the high frequency waves used to conduct television signals are susceptible to reflection by relatively small objects such as buildings, metal signs, etc. These refiections often result in the production of undesirable duplicate images or "ghosts" on the receiver screen. Refiective conditions are often times subject to quick change, especially in a, community subject to rapid growth, and Where the reflections from one refiecting object may be ofiset by the reflective characteristics of a new object. Elimination of these refiections picked up by a fixed antenna therefore becomes a costly and annoying problem in those installations where the antenna is not ready of adjustment which with the high first and installation costs adds greatly to the operation of such antenna.

The present invention solves this problem by providing an inexpensive compact antenna comprised of a spaced dipole and refiector array tuned to the lowest frequency to be received which provides adequate sensitivity, gain and direction'al properties for all-channel operation because of the broad-band characteristics of the conical dipole and that can also be readily adjusted to overcome the reception of reflected signals as they arise from time to time.

It is accordingly an object of this invention to provide an antenna of demountable Construction that has desirable broad-band char-acteristics and is also capable of being readily adjusted to eliminate undesired signals.

Another object is to provide a stacked conical antenna suitable for installation within a building such as in an attic or a like area.

A further object is to provide 'an antenna of this type which eliminates the need for special fixed support means.

A still further object is to provide a closedended stacked conical antenna highly responsive to a wide range of signal frequeneies.

Another object is to provide an adjustable antenna inexpensive of manufacture, and ready of assembly at the point of use Without special tools or equipment.

With these and other objects in View that will appear from the following description of my in- Vention, which consists in the novel arrangement of cooperating parts and the combination and details of Construction disclosed, when taken in conjunction with the accompanying drawing in which like numerals refer to like parts in the different views.

In the drawings:

Figure 1 is a plan View of the present invention.

Figure 2 is an end elevation.

Figure 3 is a side view taken on line 3-3 of v Figure 2.

Figure 4 is a detail of the frame taken on line 4-4 of Figure 1.

Figure 5 is a detail plan View taken with the top frame member removed.

Figure 6 is a detail taken on line 6-6 of Figure 2.

Figure '7 is a detal taken on line 1--1 of Figure 2.

Referring now in details to the drawings in which is illustrated the antenna array I a generally of this invention which is comprised of a pair ll and |2 of stacked conical dipoles or driven" elements swingingly mounted to a vertical upright !3 of a wooden frame I& spaced forwardly of a reflector means 15 formed of oppositely disposed sides or panels 31 and 38 carried by the same frame. The refiector panels 31 and 38 are angularly adjustable relative to the Wood frame I 4 and are generally positioned at right angles to the frame. In orienting for certain stations it may be found desirable to angle the refiector panels 31 and 38 rearwardly or away from the e "driven dipoles ll. The construction of frame M is preferably that of Wood although it is obvious that any other insulating material can be used. The frame M consists of a front vertical member l3 spaced forwardly of a rear vertical member IE joined at the top and bottom by horizontal spacing members 11 and !8. The lengths of spacing members l' and 18 are preferably selected to provide a one-fourth wavelength operation at the mean frequency at which the antenna is designed to operate as a half wavelength antenna array. In this mannerselfsupport is provided for the antenna array suitable for quick assembly in the attic or similar.`

storage space of the building in which it is to be operated. In the assembled position of the antenna the bottom spacing member i? ispreerably placed on the top surface of the flooring 19 or supported by the joist or like members found in conventional building Construction.

The pairs of dipoles II and 52 are formed of suitable metal tubing such as aluminum tubing of such diameter to provide the resonance desired. The tubing material of which the dipoles H and 12 are constructed is cut into sections of suitable length to provide a resonant array in a conical antenna of this type. Means for mounting the tubing sections is provided by fiattening their ends as at 20 which ends are then apertured for bolting together or to the supports. Each of the vertical supports 13 and !5 are provided with pairs 2! and 22 of spaced metal strips extending vertically thereof and attached to the vertical strips by suitable screw means 23. The pairs of strips Zi and 22 are provided with angularly displaced ends 2:! arranged as mount points for the inner ends 25 of the dipoles H and &2 bolted thereto by suitable bolt means 26 so as to provide for limited angular movement about points 24 The dipoles H and 12 are ormed with oppositely displaced arrays formed conical in shape having side tube sections 27 and 28 of uniform length extending outwardly in their assembied positions from the vertical strips Zi. The outer ends 29 and 3:) of the cones are closed by a vertical tube 3! spaced oppositely from the apexes 32 of the cones Situated adjacent the vertical strips 2l. The vertical tube 3! can be either ormed as one tube as best illustrated in Figure 2 with a fiattened midpoint 33 arranged for bolted engagement with the outer ends 29 and 38 of the cones or it can be formed in separate sections closing the ends of the cones. Clcsing the ends of the conical dipoles enables me to provide a conical configuration wherein the dipoles appear electrically longer in a small compact antenna suitable for use in a relatively small area. I have found it 'desirabie to cut the dipoles for the lowest frequency desired which will then provide or eiiicient response over all of the television band extending from 54 to 216 megacycles. For instance, the length required for good reception on channel 2 (54-60 megacycles) is approximately 46 inches long on each side of the cone so as to effect a dipole 92 inches in length whereas I attain the same pattern with the closed ended conical dipoles of this inventon with cone sides El and 28 forrned of approximately 36 inches in length.

A conventional twin lead 300 ohm transmission line 34 is joined to midpoints of ,the pairs of dipoles H and 12 by being bonded across the vertical metal strips 2! as at 3'5.

spaced rearwardly from the dipoles ll and 12 as previously described is a reflector [5 constructed in similar manner and with similar material as the dipoles. The inner ends 36 of the reflector 15 are similarly bolted to the ends of strips 22 carried' by the vertical !6 so as to provide for angular adjustability of the reflector !5 to match the adjustment of the dipoles. The two sides 31 and 38 of the refiector 15 are bonded together by an electrical bond means or flexible metal strip 39 extending across the separated pair of strips 22 and bolted thereto by suitable bolt or like means 40. The bonding strip 39 extending between the refiector panels 31 and 38 is of a predetermined length and functions to make the refiectors electrically longer than the driven elements or dipoles ll while retaining thesame physical dimensions laterally of said elements.

This Construction provides a unique antenna array inexpensive of manufacture and ready of assemblage by a relatively unskilled person. All that is necessary is to assemble the parts together within the available space in which the antenna is to be located and connect the receiver transmission lead 34 to the dipoles and turn the array as found necessary for orientation of the receiver to the desired sending Stations. Discrimination as to Stations is readily attained by angular adjustment of the dipoles relative to their pivot mounts 24. Tests of the antenna constructed as described above have shown that they are not only efcient from an electrical standpoint but that they also are highly discriminatory in the elimination of reected waves. It is obvious that after the antenna dipoles H and l2 and the reflector !5 have been once adjusted that no further change will be necessary unless or until there is a structural change in the Vicinity sufricient to set up additional double image or ghost produc'ing reflections. If, as and when these conditions arise it then becomes a very simple matter for the user of the antenna to re-adjust the antenna array ll) of this invention to eliminate such undesired reflections.

The form of the inventionillustrated and described herein is the preferred embodiment of the present assemblage in the form now commercially manufactured; however, it is to be understood that this embodiment is for illustrative purposes only and it is pointed out that various modifications and alterations may be made within the scope of the appended claims.

I claim:

1. A television antenna comprising a generally rectangular rame, said frame being formed of non-conducting material and adapted for vertical positioning relativeto a floor in a building, a pair of spaced conducting strips carried by one side of said frame, said strips having end portions bent at right angles to provide horizontally disposed spaced pivot mounts, a pair of stacked conical dipoles having their apex portions swingingly carried by said spaced pivot mounts, said dipoles having their outer ends closed by vertical members extending therebetween, and a reflector means having refiecting strips swingingly carried by the side of said frame disposed opposite from said one side, said reflecting strips being joined at the ends thereof as a plurality of irregular triangle shaped rod structures with the apexes of said structures electrically bonded together.

,2. A television antenna comprising a generally rectangular Wooden frame having spaced opposite *side members and spaced end members, a pair 'of stacked closed end conical dipoles swingingly carried by one of said side members, said dipoles having apex ends connected in parallel for connection to a. transmission lead, a reflector carried by the other one of said side members, said reflector having oppositely extending refiecting arms having inner ends swingingly attached to said last mentioned side member and outer ends adjustable for parallel positioning relative to said dipoles, and bond means extending between said refiecting arms.

3. A television antenna comprising spaced nonconducting support members, a closed end dipole having oppositely extending poles carried by one of said support members, said poles having inner ends pivotably Secured to said support With free ends extended therefrom for independent angular adjustment of said free ends, said inner ends being connected for paralle connection to a, twin lead transmission line, and a reflector means carried 20 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date D. 156399 Baldi Dec. 13, 1949 2,175,253 Carter Feb. 15, 1938 2,371,539 Morch Mar. 13, 1945 2,494,665 Marshall Jan. 17, 1950 2,535,049 De Rosa, Dec. 26, 1950

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