DE550515C - Circuit for direct pointing direction finding methods - Google Patents

Description

Circuit for direct-pointing DF methods These are DF-receiving methods known in which the high frequency of a directional system modulates low frequency and that of an omnidirectional antenna is superimposed in such a way that the one that can be sieved out Low frequency takes part in the phase jump of the high frequency. On a phase indicator for low frequency, for example a dynamometer, whose stator depends on the modulation frequency direct . is pre-magnetized, while the rotating system of the screened out low frequency is flowed through, the phase jump can then be made visible, whereby the Minimum position or the deviation from it in one sense or the other recognizable is.

In the known methods, the directional system is modulated such that, for example, a loop antenna is symmetrically divided and each frame half a strongly negatively biased auxiliary pipe is connected to the grid side at each, wherein this negative bias is canceled in push-pull by the low frequency. The frame high frequency is so opposite in the double low frequency rhythm modulates the low frequency used for modulation and bias. By Superposition with the unmodulated high frequency of the omnidirectional antenna is only the original low frequency is effective in the audion. -This circuit arrangement turns out to be turn out to be unfavorable as soon as the straightening system is not permanently mounted on a vehicle and the direction is determined by changing the vehicle course, but the receiving system is stationary or the vehicle course cannot be changed and by turning the straightening system manually or automatically, the position is minimized Reception is to be tracked.

According to the previous methods, four slip rings are required here, which feed the high frequency of the symmetrically subdivided directional system to the receiver.

The present new invention is based on a circuit: allowed with only two. Power supply from the straightening system to the servicing. This is possible because of this. that only one modulation tube is used: in its Lattice circle the high frequency of the: directional system, for example the - Arikgpplungsspule of a goniometer according to Fig: -r ,: is placed. The working point is due to the preload of the modulation tube H so relocated to the kink of the characteristic that the additional modulation voltage with positive half change increase, with negative Reduction of the high frequency causes. That modulated to the rhythm of the low frequency High frequency becomes non-directional with the unmodulated high frequency energy Antenna combined, which must be ensured by appropriate tuning means; that the alternating current obtained from the omnidirectional antenna is as in phase as possible or in phase opposition to the anode alternating current of the modulation tube H is. Under these conditions, a low-frequency Alternating current of the same frequency as the modulation. filter out frequency, the participates in the phase jump of the high frequency of the directional antenna, which is what the dynamometer D is made visible, the stature of which comes directly from the low frequency generator G is excited.

Will be a phase sensitive low frequency indicator, for example a dynamometer D, on the one hand directly from the generator G, on the other hand from the low frequency fed from the receiver, this shows with a minimum position of the goniometer coil no deflection, when deviating from the minimum deflection in one sense - in a certain direction, - in the event of a deviation - in the other sense, deflection in the opposite direction Direction. If, for example, the circuit is made in such a way that when rotated: the goniometer coil from the minimum to the right one pointer deflection after. to the right takes place and vice versa, then corresponds to a change in the angle of incidence of the waves a pointer deflection to the left by z80 ° of a coil deviation to the right and vice versa. This is a single deliberate twist of the coil from the minimum the page identifier is given immediately and clearly.

Anode modulation can be used instead of grid modulation or a modulation based on the push-pull principle.

Instead of a single goniometer coil wound in a crisscross fashion Frame coil, two individual coils can also be used in one frame coil each.

In order to avoid the tuning of the antenna, this is useful deliberately overruled and the type of coupling chosen so that antenna and frame energy act on the recipient in the same or exactly the opposite phase if possible.

Phase-sensitive relays can also be used as phase indicators right and left deviation, for example by the lighting up of light bulbs or allow the precise minimum position to be recognized: Using phase relay arrangements Furthermore, as shown, for example, in Fig. a, the direction finding method can be made direct-pointing be by moving the goniometer coil through appropriate mechanical and electrical Intermediate links are automatically turned to the minimum, so that a right deviation of the coil from the minimum results in a left correction and vice versa. Included can the circuit like this. be hit - `den that the coil stops at a minimum and so at the pointer position at any time the direction in which the electric waves fall can be read.

Finally, with the axis of the goniometer coil, elements for a Registration device are connected or intermediate links are coupled to it, the one long-distance. Allow transfer of the coil position.

For checking and initial setting of the automatic DF system the arrangement is expediently made, - that under temporary disconnection the self-adjusting device - the goniometer = coil arrangement also rotated by hand can be.

If the direction finder is on a vehicle, it can be Use of the above mentioned phase-sensitive relays instead of the coil itself the control of the vehicle is so affected; that - the whole vehicle like that is controlled that for the previously selected setting of the goniometer coil .o ° or z8o ° the longitudinal axis of the vehicle automatically _ continuously in the direction of _ the The transmitter is held towards or away from the transmitter. With other course selector settings describes the vehicle inwardly or outwardly directed spiral tracks, at 9o ° position- the course selector's circular orbits around the transmitter as the center point. -

Claims (1)

PATENT CLAIM: Circuit for direct-pointing direction finding methods, whereby the high-frequency energy of a directional system is low-frequency. modulated and superimposed in phase with the high frequency of an omnidirectional antenna in such a way that the low frequency filtered out in the audion of the receiver is equal to that of the modulation frequency and takes part in the phase jump of the high frequency of the directional system if it is swiveled by the position of minimum reception, this phase jump is read on a dynamometer, the fixed system of which is pre-excited by the modulation frequency, characterized in that the high-, frequency of the directional system is fed to only one tube on the grid side, the grid = or anode side is influenced by the low-frequency modulation frequency so that the - The anode high frequency is modulated by the fundamental wave of the low frequency - and is thus superimposed with the non-modulated high frequency of the omnidirectional antenna.