US1811357A - Wireless signaling apparatus - Google Patents

Description

June 23, 1931. E. KARPLUS WIRELESS SIGNALING APPARATUS Filed March 11, 1929 Patented June 23, 1931 UNITED STATES PATENT OFFICE EDUARD KARPLUS, OIE BERLIN-T'EMPELHOF, GERMANY, ASSIGNOR '10 0. LORENZ AKTIENGESELLSGHAFT, OF IBERLIN-TEMPELHOF. GERMANY WTRELESS SIGNALING APPARATUS Application filed March 11, 1929, Serial No. 345,914, and in Germany Kay 12, 1928.

In the construction of transmittersv and receivers for short and ultra-short waves, special precautionary measures have to be taken, since all the oscillation circuits shrink to @quite unusually small dimensions. For this reason, it is not possible simply to place an apparatus for the purpose of protection from external disturbing influences inside a metal casing and to earth the same. When operat- |1o ing w1th longer wave-lengths, this is possible without difficulty, since the lead to the antenna can be simply led out from the casing in an insulated manner in order to be connected to the'antenna. The antenna circuit I is, however, in devices for ultra-short waves, only several centimeters long and its entire energy would be taken from it if it were arranged in close proximity to the screening casing. Further difliculties arise, for into stance, in aircraft stations, since the small antenna circuit must at all events be arranged outside the flying machine but longer leads to the same, cannot be attached. In this case therefore, the whole apparatus had to be installed outside the flying machine, on which account however, the manipulation of the same was impossible. The disadvantages described are avoided, according to the invention, by arrangin the circuits conveying low-frequency, me 'um frequency and direct current, in a screened earthed metalcasing and makmg the connection with the circuits conveying high-frequency which are separated in space, galvanically y means of leads which are screened by a metallic protective covering and which do not convey any hi h-frequency. The figure in the rawing shows one form of my invention, with parts of the housings 40 broken away to diagrammatically disclose part of the transmitter circuit.

In the drawing of the subject of the invention given by way of example, the highfre uency part is indicated by HF and the modulation or low-frequency part by NF. The high-frequency transmitter given by way of example is connected in the manner usual.

with short-wave stations. The tunable oscillation circuit LG; is connected, under the ino termediate connection of the usual condenser G with the anode and the grid of the valve R The anode voltage is introduced to the neutral point of the intermediate circuit L. The supply conductors of the heating and anode current are bridged over by capacities G and C, in order to prevent high-frequency flowing in the same by making a short-circuit for high-frequency. The actual high-frequency transmitter is arranged inside a suitable casing, which mayconsist of weatherproof material or insulati'n material, in order that it should be possib e also to arrange the transmitter somewhat outside the flying machine already mentioned atithe beginning.

All the batteries in addition to the. modulation arrangement or keying-arrangement are situated in an earthed metal casing G. A Heisin modulation circuit is diagrammatically s own in the figure. The microphone must, of course, be outside the casing and is connected at M, in order to influence the grid ofthe valve R through a transformer U. The heating'batteries B and B in addition to the anode choke D are likewise inside the casing. The connection with the high-frequency part is made by lines, which, in the example shown, are inside a flexible metal tube S which is connected with the casing G. It is obvious that any desired modulation or keying arrangement can be arranged inside the casing and that the connecting line together with the flexible metal tube can be adapted to be plugged in. For special purposes, it is also desirable to replace the flexible metal tube by a stiif tube and to carry the high-frequency transmitter by means of the tube itself.

The separation, according to the invention, of the high-frequency part from the other parts can be carried out equally well in the case of a receiving apparatus. The wavelength of the transmitter can, of course, be firmly adjusted, but on the receiving side, a corresponding receiving apparatus must be used which need not be tuned in the highfrequency part. Either a receiver which is little selective is used or a superheterodyne receiver or super-regenerative receiver, the auxiliary frequency of which is conveyed to the high-frequency receiver likewise by leads,

which are led in the flexible metal tube. It is unnecessary to explain the circuit in more detail by aid of a figure, since in short-wave devices, the transmitting and receiving circuit are the same in principle and well-known of themselves. It is also possible without difiiculty, with particular receiving arrangements, to arrange the medium frequency part also in the metal casing.

, What I claim is:

1. Anapparatus for wireless signaling by ultra-short waves'comprising two parts arranged in s aced relation to one another, the first of sai parts including the circuits for high frequency and the second of said parts comprising a screened metal casing connected with earth and including circuits for lowfrequency and direct current; the said two parts being connected galvanically through leads which are screened by a metallic protective covering, and condensers shunting said leads at their connection points with the high frequency circuits.

2. An apparatus for wireless signaling by ultra-short waves comprising two parts arranged in spaced relation to one another, the first of sai parts including the circuits for high frequency and the second of said parts comprising a screened metal casing connected with earth and including circuits for medium, low-frequency and direct currents; the two parts being connected galvanically through I leads which are screened by a metallic protective covering, and condensers shunting said leads at their connecting points with the high frequency circuits.

3. An apparatus for wireless signaling by ultra-short waves comprising two parts arranged in spaced relation to one another, the first of said parts including the circuits for high frequency and the second of said parts comprising a screened metal casing connected .with earth and including circuits for lowfrequency and direct currents; the two parts being connected galvanically through leads enclosed in a flexible metallic tube, and condensers shunting said leads at their connecting points with the high frequency circuits.

4. An apparatus for wireless signaling by ultra-short waves comprising two parts arranged in spaced relation to one another, the first of said parts including the circuits for high frequency and the second of said parts casing enclosing the circuits for highrequency and the second of said parts comprising a screened metal casing connected with earth and enclosing circuits for medium-frequenc low-frequency and direct currents; the said two parts being connected galvanically through leads screened by a metallic protective covering, and shunt condensers at the connection points of said leads with the highfrequency circuits.

In testimony whereof- I have affixed my signature. 9o

EDUARD KARPLUS.

comprising a screened metal casing connected with earth and including circuits for mediumfrequency, low-frequency and direct currents; the two parts being connected alvanically through leads enclosed in a flexilfle metallic tube, and condensers shunting said leads at their connecting points with the high frequemgncircuits.

' 5. apparatus for wireless signaling by ultra-short waves comprising two parts arranged in s aced relation to one another, the first of sai parts comprising a water-tight

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