US2318271A - Antenna transformer - Google Patents

Description

Patented May 4, 1 943 ANTENNA TRANSFORMER Walter Weiche, Berlin, Germany, assignor to C. Lorenz Aktiengesellschaft, Berlin-Tempelhof, Germany, a company Application October 10, 1941, Serial No. 414,456 In Germany July 15,1940

7 Claims.

This invention relates to transformers of the kind serving to join directive antenna systems to the feed lines and goniometers, the resistance of such antennae being high compared with that of the feed lines and goniometers.

In the case of Adcock systems these transformers while being of substantially the same electric symmetry should also agree with each other as regards inductance, capacity, resistance and quality coefficient and in addition should be'bf the same amplitude and phase conditions, because trifling variations of amplitude and phase can entail frequency-controlled faulty indications.

Transformers of this kind are also required to be invariabl in efficiency and independent of climatic conditions. Variations of temperature by :40" C. and the air moisture are not allowed appreciably to affect the electrical characteristics of these transformers.

In order to achieve this, transformers as provided by the invention are constructed symmetrically and fitted with two cores of high frequency iron which are movable along the axis of the transformer. By means of these cores the transformers can be precisely adjusted. It is known in itself to adjust high frequency coils with the aid of high frequency iron cores. However, prior devices of this type serve to tune the inductance, whereas the novel arrangement is concerned with the phase angle, transition ratioand with balancing asymmetric windings.

In the drawing, forming part of this specification, Fig. 1 is a sectional view showing one embodiment of the invention, Fig. 2 is a sectional view representing another embodiment thereof. Fig. 3 illustrates a section on line 33, Fig. 2.

The arrangement shown in Fig. 1 has an iron core I pressed onto a shaft 4 or fixed to it by a suitable cement. Shaft 4 also carries two iron cores 8 which are screwed onto it. 2 designates a sleeve carrying a primary coil T to which an antenna, constituting the high resistance part, is connected. The cores 8 are readily displaceable within sleeve 2, sufficient room for play being provided between sleeve and cores. notes a. sleeve carrying a secondary coil U to which a goniometer, constituting the low resistance part, is joined. Between the sleeves 2, 3 an electrostatic shield 5 is located. The means 5 may be a slotted tubular body or a cylinder of wire gauze or the like. Glands 9 are carefully positioned with the aid of intermediate discs I made of ebonite, for instance, and are confined upon shaft 4 by nut screws ll.

Two discs of high frequency iron and a shell of Lil the same material may be arranged to close the iron path of the transformer.

When such a transformer has been assembled it is adjusted by displacing the cores 8 along shaft 4. Screws l3 are arranged to secure the cores 8 in the desired position. A plate l2, confined upon shaft 4 by a nut screw l4, serves to fix the transformer in a suitable casing. l0 denotes washers for the nuts ll, 14.

While in the construction shown in Fig. 1 all the parts thereof are carried by means of shaft 4, the arrangement illustrated in Figs. 2 and 3 has no such shaft, the inner sleeve or coil carrier 2 being in its turn arranged as a support. The transformer so constructed is perfectly shockproof. Sleeve 2 may be used to carry either the low resistance winding or the high resistance winding. The coil-carrying sleeves 2, 3 are held together by means of an annular nut screw l5 screwed onto sleeve 2. 5 again denotes a static screening means located between the sleeves 2, 3. Two cores 8' of high frequency iron are in threaded engagement with the ends of the sleeve 2. The assembly 2, 3. I5 is mounted in bearing pedestals 6 formed in one piece to provide a common support. Upon the pedestals B brasses or clamps H are fixed by screws 20. The pressure in this way exerted upon the threaded ends of sleeve 2 is such that longitudinal slots Q provided therein are compressed so as to prevent the cores 8' from being displaced in any wise. l9 denotes elastic intermediate layers while Hi indicates intermediate discs and 2| denotes washers. In order to avoid the attenuation being altered by weather conditions and moisture, the windings on the sleeves 2, 3 may be provided with a lacquer coating or may be treated in any other way adapted to render the electric constants thereof invariable.

The transformer is arranged in a box 24 with lid 23. This box acts to screen the transformer and to protect it from injury. The box also enables the transformer to b readily joined to any system in a manner to preclude the electric characteristics of the transformer being affected to any extent.

In this way, all the adjusting transformers employed in'a directive antenna system may be made to be equivalent while being prevented from undergoing any variation of their electrical properties.

What is claimed is:

1. A transformer including a primary coil and a secondary coil coaxial with each other, a separate carrier for each said coil, one of said coils and the carrier thereof surrounding the other of said coils and the carrier thereof, and two cores of high frequency magnetic material displaceable along the axis of said coils and disposed in symmetrical relation with each said coil.

2. A transformer according to claim 1, in which a shaft is provided for carrying said cores and carriers.

3. A transformer according to claim 1, in which a shaft is provided for carrying said cores and carriers, said shaft having a third iron core mounted rigidly thereon between said first two cores and disposed symmetrically with respect to said coils.

4. A transformer according to claim 1, includmg two pedestals having a common support, said inner carrier being mounted on said pedestals, said outer carrier being supported by said inner carrier.

5. A transformer according to claim 1, in which said outer carrier is supported by said inner carrier, a support being provided for each end of said inner carrier, said cores being adjustably screwed into said inner carrier.

6. A transformer according to claim 1, in which a support is provided for each end of said inner carrier, said outer carrier being supported by said inner carrier, each said core being in screwthreaded engagement with a respective end of said inner carrier, and means for clamping the end? of said inner carrier in said respective supper 5. s

7. A transformer according to claim 1, in which anfleiectrostatic shield is disposed between said co s.

WALTER WEICHE.

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