US2538497A

US2538497A - Antenna connector system

Info

Publication number: US2538497A
Application number: US785245A
Authority: US
Inventors: Harland A Bass
Original assignee: Avco Manufacturing Corp
Current assignee: Avco Manufacturing Corp
Priority date: 1947-11-12
Filing date: 1947-11-12
Publication date: 1951-01-16
Anticipated expiration: 1968-01-16

Description

Jan. 16, 1951 H. A. BAss ANTENNA CONNECTOR SYSTEM Filed Nov. 12, 1947 CONVER TER CIRCUIT FOR- CHANNEL SELECTOR UNIT CIRCUIT ENNA MER C/RCU OSCILLATOR CHANNEL SELECTOR UNIT METAL INSULATION Ill METAL Patented Jan. 16, 1951 OFFICE ANTENNA CONNECTOR SYSTEM Harland A. Bass, Mount Healthy, Ohio, assignor to AVCO Manufacturing Corporation, Cincinnati, Ohio, a corporation of Delaware Application November 12, 1947, Serial No. 785,245

2 Claims.

3 The present invention relates to a novel antenna connecting system for electromagnetic wave energy receivers. While it has a considerable range of prospective utility. it is most efiective in providing a very flexible antenna system for television receivers. The invention is particularly adapted for incorporation in the novel channel selector units disclosed and claimed in U. S. Patent 2,507,995 to John D. Reid, entitled Television Receiving System, issued May 16, 1950, and assigned to the same assignee as the present application and invention (AVC'O 'Manufacturing Corporation). Briefly described, the invention contemplates. for use in association with a special antenna optimized for a particular channel or group of channels. a receiver-input plug provided with terminals adapted to be connected or disconnected at will to said antenna, 'a socket adapted to receive said plug and having terminals spaced from said plug terminals, a general antenna suitable but not optimized for a greater number of channels and adapted to be connected to the socket terminals, and removable conductive extensions adapted to connect the plug terminals to said socket terminals and to couple the general antenna to the receiver input. Such extensions are employed when the general antenna is used and are removed when the special antenna is used. In the latter event, the special antenna is directly connected to the receiver input plug.

It is often desirable to provide a plurality of antennas for a televi ion receiver, each specially designed and oriented to provide for optimum interce tion of si nals in a particular channel or a grou of neighboring channels. Since television transmission and reception involves veryhigh-freouency electroma netic waves, reflecting images not only occesion de tructive interferences but they also cause dupl cation of images and the phenomenon known to those skilled in the television art as ghosts, unless suitable precautions are taken to minimize reflections. The best precautions to be taken depend on the direction of the individual tran mitting station relative to the television receiver and on the nature of the vari I ous obstacles encountered by wave energy propagated from that station to'the receiver. The best precautions as to receiving antenna design and location to be taken for a station having one bearing with respect to the receiver are very different from those to be taken for a station having a diiierent bearing with. respect to the receiver. It is, of co rse, possible to employ one antenna for all availa le television channels and stations in'a give'n' location 'but at the cost of a drastic loss in efficiency and other desirable receiver characteristics. It is therefore highly desirable to provide a simple and flexible antenna system for television receivers.

When the dimensions of the wave-intercepting elements become comparable to the wave lengths of the signals beingtransmitted and received, as in the case of television, the directional characteristics of an antenna are highly functionally dependent on Signal frequency. A given antenna which manifests one directional pattern during reception of signals in a given channel may display entirely different directionalpattern characteristics when receiving signals in another channel. To exploit optimum directional characteristics and patterns for each channel often requires the use of separate antennas for the individual channels 'or related groups of channels. This is another reason Why it is desirable to employ a plurality of antennas in a television receiver and to provide a simpleinexpensive and easily operable antenna-connecting system for coupling a desiredone of the antennas to the receiver input whereby optimum wave intercepting conditions may be realized for each channel;

Stated in another way, signals from the various channels are received with optimum signal intensity when optimum directivity characteristics are realized for each channel. It is often impossible for one general antenna to manifest optimum directivity characteristics for all of the available channels. This is particularly true if there be considered the extreme case of two available channels associated with two transmitting stations having bearings at right angles relative to the receiver.

For all the foregoing reasons, including the impossibility of designing one antenna having uniform directivity characteristics over an extremely broad band, proper television receiving practice requires facilities for the ready and easy coupling of optimized special antennas to the receiver input. It is an object of the invention to provide such an antenna connecting system.

A specific object of the invention is to provide, for use in conjunctionwith any desired one oi one or more special antennas each optimized for a 'specific channel or group of channels, are ceiver-input connector member provided with terminals adapted to be coupled to the appro-' priate one of said antennas, a complementary cinnector member adapted to engage the first mentioned connector member and-having terminals spaced from the first-mentioned tel-' minals, a general antenna adapted to be coupled including channel selector units embodying a preferred illustrative form of antenna connector system in accordance with the invention.

In the drawings, Fig. 1 is a sectional view through a pair of channel selector units, showing an antenna connecting system in accordance with the invention and sufficient of the associated wiring and circuit units to make clear the construction and operation of the invention; Fig. 2 is an.

enlarged sectional view through the plug and socket terminals and the removable extensions provided in accordance with the invention; and Fig. 3 is a perspective view of those elements.

Referring now specifically to Fig. 1 of the drawings, there is illustrated in schematic and abbreviated form a channel selector unit system as described and claimed in the above-mentioned copending patent of John D. Reid. The general function of that system is to apply to the converter circuit II received signals and local oscillati'on's optimized for each individual channel. To that end there is provided in accordance with the Reid invention a plurality of channel selector units illustrated generally in block and outline form at I2 and I3. A channel selector switch I9 is also provided and it performs the function of interposing either the channel selector unit I2 or the channel selector unit it between the wave intercepting system and the converter circuit unit, depending on the station from which the operator desires to receive. For a complete description of the Reid invention, reference is made to the abovementicned copending patent. Briefly, however, each channel selector unit includes an antenna transformer circuit generally shown at i i and a local oscillator circuit generally shown at Er). The antenna transformer unit it includes a primary having leads which are connected to receiver-input terminals i5 and E5 of a plug connector member. The output of the antenna transformer circuit is connected to terminals I! and I8, also carried by this plug connector. The input terminals are adapted to be coupled to an antenna and the output terminals are adapted to be coupled to the converter unit 5 l. The antenna transformer circuit is designed to voltage amplify the received signals and to select that channel and to apply the signals under optimum conditions to the converter unit 5 i.

The channel selector unit also includes a local oscillator circuit it, which is coupled to the output terminals ii, IS in such a manner as also to apply local oscillations of great frequency stability to the converter unit ii. All components of the channel selector unit I2 are so designed that no Vernier tuning is necessary and that signals in its channel may be received under optimum conditions. The channel selector unit i3 is designed for a different channel and in such a way that its antenna transformer input circuit and its local oscillator circuit are optimized for its appropriate channel. Switching from one channel to another is effected by the operation of in ots-no i e eeior sw tch it "W Q --9 l 4 appropriate ganged sections here symbolically shown.

The Reid construction readily and easily lends itself to the novel antenna connector system provided in accordance with the present invention. The illustrative channel selector units shown are of a single-channel type while those shown in the Reid patent drawings are of the two-channel type. The present invention may be most simply described by a showing of the single-channel type of channel selector unit since the same antenna considerations apply to both types of units. In accordance with the present invention, in lieu of prongs of the general type shown at I! and I8, the antenna terminals of the plug-in channel selector unit I2 comprise a pair of screws I5, I6 rigidly appropriately secured to and projecting downwardly from a suitably insulated metallic base 23. This base is provided with an insulating strip 22, carrying the terminals.

Nuts 22 and 23' provide binding posts for the leads 24 and 25, respectively, of a special an.- tenna 26' which may be optimized for the particular channel, as, for example, the channel of unit I3. When unit I3 is selected the pair of double-pole, double-throw sections of switch I9 are. thrown to their lower positions whereby the output of channel selector unit I3 is coupled to the converter circuit II. Special antenna 26 is already coupled to the receiver input. under this assumed condition.

It will be noted that the leads 28, 29 r the general antenna 39 are adapted.- to be coupledto the socket terminals 33-3 or 3334', respectively, associated with the channel selector unit I2 or the channel selector unit I3, depending. on the position of the channel selector switch I 9. When the switch is in, its lower position general, antenna 30- is disconnected from the. channel selector unit i3 because of the fact that the screws !5 and I5 are of insufficient length to contact the

metallic socket terminals

33 and 34,.respectively. Therefore the special antenna 26' alone is coupled to the channel selector unit I3.

It will be assumed that thegeneral antenna 3i) is employed in conjunction with channel. Sel tor. unit I2. When switch [9 is thrown. to its upper position, plug terminals I5 and i8 are elec trically in conductive relationship to the

socket terminals

33 and 34 and unit I4 is coupled to the general antenna 38, by reason of removable conductive extensions 4!] and 4|, respectively, provided in accordance with the invention.

In any case wherein it is desired to connect a special antenna to any particular channel, the

removable extensions 40, 4| may be removed from the plug-in channel selector unit, leaving the short screws I5, I6 in place. The lead-ins from an appropriate special antenna may th n be secured to these screws with nu s, such as 22, 23 and the channel selector unit re-inserted in its socket. The screws I5, I 6 are sufficientl short so that contact is no longer made to the socket and the common antenna 30 is disconnected from the corresponding antenna input transformer, such as 14.

It willbe noted in the system illustrated in Fig- 1. that the common antenna 30 may be employed with either the channel selector nit l or th channel selector unit I3. In the latter event, nuts 22 and 23' are loosened and leads 24225 disconnected therefrom and removable extensions corresponding to 4.0. 1 are screwed on to the shortscrews 15. I5.

The veei in st- 1 mer t ph a ant flexible antenna system for television receivers, particularly those employing the novel channel selector units disclosed and claimed in the abovementioned copending Reid patent. The present invention embraces, for use in conjunction with any desired one of one or more special antennas, such as antenna 26, a receiver input plug provided with terminals i5, 16 adapted to be connected to any one of said special antennas, a socket adapted to receive said plug and having

terminals

33, 34 spaced from said plug terminals, a general antenna 36 adapted to be connected to the last-mentioned

terminals

33, 34 and removable. extensions 49, 41 adapted to connect the plug terminals to the socket terminals and to couple the general antenna 30 to the receiver input. The general antenna may be optimized, of course, for the channel of unit 12, if desired.

While there has been show and described what is at present considered to be the preferred form of the present invention, it will be obvious to those skilled in the art that various modifications and substitutions of equivalents may be made therein without departing from the true invention, and it is accordingly intended in the appended claims to cover all such changes and modifications as fall within the true scope of the invention.

Having thus described my invention, I claim: 1. The combination of a television receiver having an antenna input circuit, a dipole antenna and means for normally conductively connecting said antenna to said input circuit, said means comprising a socket, formed with a pair of conductive wells connected to said antenna, and a plug, said socket also having a second pair of wells, said plug comprising an insulating support member formed with a pair of apertures therein, a pair of threaded metallic screws permanently conductively connected to said antenna input circuit and projecting through said apertures, a pair of threaded nuts fitting with said screws to secure them to said support member, and a pair of internally threaded conductive metallic prongs individually removably mounted on the portions of said screws which project through said nuts, said prongs being so shaped and registered as to contact said conductive wells when said plug and socket are mated, said prongs being removable to disconnect said antenna from said input circuit whereupon another dipole antenna may be connected to the binding posts provided by said nuts and screws, said plug also having a second pair of prongs, permanently secured to said support n: Ou

member, which engage said second pair of wells to maintain said plug and socket in mating relationship whether or not said prongs have been removed from said screws.

2. A connector device for normally connecting but optionally disconnecting a television receiver from a two-terminal antenna comprising a socket formed with a pair of conductive wells adapted to be connected to said antenna, a plug comprising an insulating support member formed with a pair of apertures therein, a pair of threaded metallic screws adapted to be permanently conductively connected to said receiver and projecting through said apertures, a pair of threaded nuts fitting with said screws to secure them to said support member, and a pair of internally threaded conductive metallic prongs individually removably mounted on the portions of said screws which project through said nuts, said prongs being so shaped and registered as to contact said conductive wells when said plug and socket are mated, said prongs being removable to disconnect said antenna from said receiver whereupon another antenna may be connected to the binding posts provided by said nuts and screws, said socket also having a second pair of wells, said plug also having a second pair of prongs, permanently secured to said support member, which engage said second pair of wells to maintain said plug and socket in mating relationship, whether or not said prongs have been removed from said screws.

HARLAND A. BASS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS