DE494222C - Method for reducing the effect of fading in wireless reception - Google Patents

Description

For the purpose of eliminating the loss, it has been proposed to use various To set up several separate receivers and their outputs in one to unite common circle with which the device for displaying the signal is coupled. With this arrangement, when a signal fades at one point and the recipient at that point doesn't die

ίο absorbs the desired signal energy, equals one of the other recipients made this loss so that one was even on the whole Has reception. After all, with this arrangement the receiver in question still reproduces the unwanted noises, generated by atmospheric or other disturbances.

The invention relates to an arrangement in which the receiver does not use the useful energy absorbs, is automatically limited in terms of amplification or sensitivity, so that the background noise is not significantly amplified or combined with the useful signal will.

The further invention relates to a receiving arrangement consisting of several separate ones Receivers that are set up at different points where all receivers, except one, limited in sensitivity or gain if that one receiver is working properly.

Another invention is that the plurality of separate receivers one Operate common display device.

The invention is illustrated in the drawing in two figures, of which FIG. 1 Figure 2 shows a general circuit diagram and Figure 2 a detailed circuit diagram.

The receivers 1 and 2, each with their own antenna, are with any Set up a distance from each other at two different points. With the starting circle of a high-frequency amplifier of the receiver r is the input circuit of a sensitivity control device 1, the output of which is connected to the input circuit of a high-frequency amplifier of receiver 2 connected is. Similarly, the output of an amplifier 2 is connected to the input a sensitivity amplifier 2 and its output to the input of an amplifier ι connected. The final audible frequency outputs of the two receivers are then combined and fed to the display device.

The mode of action is as follows.

Assume that the signal from the receiver 1 is of normal strength and from the receiver 2 with very low strength

Claims (1)

Will be received. Under these circumstances, the sensitivity control i, which is used with connected to the input of amplifier 2, to the grating of this amplifier bias so that the gain or sensitivity of receiver 2 is significant is decreased. This prevents receiver 2 from being atmospheric or other disturbances to amplify when he ίο no usable signals the final Output circuit supplies. Under these circumstances, Sensitivity Control causes 2 no reduction in gain or sensitivity of receiver i. However, if the reception conditions change and the signal is now at 1 fades, but becomes strong at 2, the mode of action is reversed and it diminishes the sensitivity control 2 the gain at i, whereby the recorded there Disruptions are reduced. If the reception strength at both receivers is poor, the sensitivity controls are activated 1 and 2 not in effect, so recipients 1 and 2 each recorded Play the signal with the greatest possible strength. If the reception strength of both receivers is great, the sensitivity will be both receivers are reduced accordingly, so that no greater energy occurs in the common output than for Actuation of the indicator is required. The device for controlling the sensitivity can, for example, in a There are tubes whose grid is supplied with a voltage that is supplied by the incoming Carrier wave is derived. In the circuit according to FIG. 2, the receiving antenna is connected to the high-frequency amplifier 11, which in turn is coupled to an amplifier tube 12. Through the Line 13, which is connected to the output of amplifier 12, is the voltage change of the carrier flow pressed onto the grid of the tube 14, wherein a Blocking capacitor 15 keeps the DC voltages away from grid 14. in the The output circuit of the tube 14 is the resistor 16, at whose terminals the lines 17 and 18 which lead to the filament or grid of the tube 20 are connected. It can be seen that the voltage changes are pressed on the grid 20 and 16 serve as the aforementioned variable bias. The audio tube 25 can with the high-frequency amplifier tube 12 are coupled in a known manner, and it can connect to them low-frequency amplifiers. The amplifier 26 is with the Output of the tube 25 coupled and its output to the common output connected. A second receiving antenna 21 is coupled to the high-frequency amplifier tube 22, which in turn is coupled to the intensifier tube 20; the exit of 20 and that The grids of FIG. 31 are with the interposition of the capacitor 32 through the line 30 tied together. At the output of 31 there is a resistor 33, which is connected through lines 34 and 35 is connected to the filament and grid of the tube 12. The audio tube 40 is coupled to the amplifier 20, with which on the other hand the low frequency amplifier 41 is connected, the output of which is connected to the common output. The mode of action is as follows. Assume that the signals in antenna 10 are strong; then the carrier voltage the grid of 14 by the line 13 pressed and causes a corresponding current in the output circuit of 14. Der Voltage drop across resistor 16 resulting from the flow of current in anode circuit 14, is pushed onto the grid of 20. If the carrier is strong in the output of 12 is, the voltage drop across resistor 16 is relatively large and causes a Bias on the grid 20 sufficient to reduce the sensitivity of this tube and so to put the receiver 2 out of operation. In the same way, if the signals in the receiver 2 are strong and are weak in the receiver 1, the carrier voltages recorded at 2 of the sensitivity control tube 31 pressed and thereby caused voltage drops across the resistor 33, which the grid of 12 can be supplied as a bias voltage that is large enough to reinforce this Reduce tubes and thereby put them out of operation. Patent license: Process to reduce the effect of fading in the case of wireless reception, characterized in that the same signal is received at different points and a part of the no Point received signal energy is used to control reception at another point, and that the at the received energy received at the various points in the same sense Receiver affected. 1 sheet of drawings