US1749269A - Externally-controlled tube transmitter - Google Patents

Description

March 4, 1930. F. TRAUTWEIN EXTERNALLY CONTROLLED TUBE TRANSMITTER Filed Sept. 17, 1926 I N V EN TOR. z'earz'ai fiaulwaz'za A TTORNE Y Patented Mar. 4 193i) rrie FRIEDRICH TBAU'IWEIN, OF BERLIN-ZEHLENDORF, GERMANY, ASSIGNOR TO THE FIRM DE. EBICH F. HUTH GEE. M. B. H., OF BERLIN, GERMANY EXTERNALLY-CONTROLZED TUBE TRANSMITTER Application filed. September 17, 1928, Serial No. 136,178, and in Germany Gctober 17, 1925.

WVhen tube oscillators in wireless telegraphy or telephony are controlled by outside means, an undesirable reaction is observable from the sending tubes to the controlling tubes. These disturbances arise through the fact that the incoming circuit as well as the outgoing circuit, that is, the antenna of the sending or amplifying tube or tubes, which carry the actual oscillating energy of the antenna, are tuned to the same wave-length, and moreover the controlling sender coupled to the incoming circuit of these tubes, is also tuned to the same frequency.

It is well-known that a discharge device with the incoming and outgoing circuits tuned to the same frequency form a well-defined oscillation generator. With the tuning used as at present to the same frequency, the sending tube would necessarily operate also as a generator, which it is attempted to prevent by a more or less round-about means, but never has it been possible to achieve completely clear oscillating conditions. There remains always more or less reduction of the damping of the incoming circuit of the sending tube coupled to the controlling tube. Through this will arise a distortion of impulses being sent, especially in telephony. This may go so far that the control circuit is so strongly influenced that its anode voltage becomes entirely insufhcient, while on the other hand the voltage of the incoming circuit of the sending tube becomes so high that it paralyzes the action of this tube too.

The invention allows of a simple means to completely avoid these disturbances. This means consists of an arrangement so that the incoming circuit of the sending tube is tuned to a frequency other than the frequency of the outgoing circuit and of the frequency of the controlling sender. As has been already explained, the reaction arises through the fact that the incoming and outgoing circuits of the sending tube are tuned to the same frequency, which causes the generator action.

The generator action of these tubes is completely eliminated by the above tuning, and in order to reduce the transmission losses due to this tuning, it is desirable to choose the frequency of the incoming circuit as a harmonic of the frequency being sent, that is, of the frequency of the control sender.

Since with such influencing of the sending tube it is possible to transmit the voltages to the grid very freely, it is desirable to choose the transforming coil with upward transmission of voltages. 7

My invention will be more clearly understood by reference to the accompanying drawing which diagrammatically illustrates my invention applied to a radio transmission system.

In the drawing an oscillator is shown consisting of a high tension source (anode batteries, or high tension machine 1) a high frequency choke 2, electron tube 3, a heating battery 4:, a coupling condenser 5, the anode or I oscillation coil 6, and a tuning condenser 7. An amplifier is coupled to the oscillator and consists of a couphng C011 8, a tuning condenser 9, a high frequency choke 10, an'elec tron tube 11, a heating battery 12, a high ten sion source 13, a coupling condenser 14:, an anode or antenna coil 15 with variometer 16, and antenna ammeter 17. The circuit 6'? is the oscillating circuit of the electron tube 3. The circuit 8-9 is the input circuit of the separately controlled amplifier tube 7. The antenna ground circuit is shown connected to the output circuit of the amplifier 11.

Having described my invention, what I believe to be new and desire to secure and protect by Letters Patent of the United States is 1. In an arrangement for externally controlled high frequency transmitter, comprising a controlling oscillation generator, an amplifier with an input and an output circuit, means in said output circuit to tune it to the transmitter frequency and means in said input circuit to prevent reaction from said output circuit, comprising a circuit tuned to a harmonic of the transmitter frequency.

2. In an arrangement according to claim 1 coupling coils between said oscillation generator and said amplifier, to act as potential transformers and a ratio of turns to give upward transformation of voltage in said transformer.

3. A transmission system for amplifying high frequency waves in substantially the same form-as they are received, comprising a controlling oscillating generator, a vacuum tube amplifier connected with said oscillator and means in said amplifier for preventing excessive resistance reduction through inherent reaction of said amplifier, said means comprising a circuit tuned to a harmonic of the transmitting frequency associated With the input circuit of said amplifier.

4. In an arrangement for externally controlled high frequency transmitters, comprising a controlling oscillation generator, a vacuum tube amplifier having filament, grid 5 and anode electrodes and being associated with said oscillation generator, an output circuit associated with the anode of said amplifier tuned to the frequency of the oscillations produced by the controlling generator, an input circuit of said amplifier coupled with said controlling generator and tuned to a harmonic frequency to the fre quency of said controlling generator.

In testimony whereof I have aflixed my signature.

DR. FRIEDRICH TRAUTWEIN.

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