Audible Antenna Alignment Apparatus

The invention concerns a system for determining the extreme value of a physical dimension.

The extreme value of a physical dimension must often be determined. It is for example important to estabish the maximum output voltage of a receiver, either to tune the device or to correctly orient a receiving antenna. A measurement receiver is known that contributes to the precise adjustment of the parabolic mirror in a satellite receiver for example (Funkschau 22 [1968], 59). A measurement receiver of this type, however, is very complex and accordingly expensive. Furthermore, it can only operated by highly-trained personnel and it is often difficult to read the optimal setting from the scale. Remote control of the optimal orientation of an antenna is also known, with the result displayed on a video-display terminal. This of course requires a monitor for the display, and this solution is also expensive.

The object of the invention is to provide the simplest possible system for determining the extreme value of a physical dimension and in particular for determining the maximum output voltage of a distributing amplifier and hence the optimal orientation of an antenna.

This object is attained by the invention recited in the major claim. Other advantageous embodiments of the invention will be evident from the subsidiary claims.

One embodiment of the invention will now be specified with reference to the drawing, wherein

FIG. 1 is a block diagram of the invention,

FIG. 2 is another block diagram of the invention, and

FIG. 3 is a circuit diagram of a detail of the system illustrated in FIG. 2 .

The optimal orientation of an antenna 1 can be determined by measuring the rectified intermediate-frequency output voltage U.sub.A of a distributing antenna 2. Output voltage U.sub.A is supplied to a voltage-to-frequency converter 3 that emits a low frequency when output voltage U.sub.A is high. The frequency of output voltage U.sub.A becomes higher as the voltage becomes lower, when, that is, antenna 1 is incorrectly oriented. The output voltage U.sub.B from voltage-to-frequency converter 3 consists of pulses I, which can for example be converted into an acoustic signal by an electrical-to-acoustic converter. The output voltage U.sub.B in the figure is exploited in the form of pulses to activate an electronic switch 4 by applying pulses I to the control input terminal C of electronic switch 4. The switch remains closed subject to the pulses and forwards a signal generated in the audible range of 1000 Hz for instance by an oscillator 5 to the input terminal A of electronic switch 4. A package of pulses I' can be obtained from the output terminal B of switch 4, amplified in a low-frequency amplifier 7, and rendered audible by an electronic converter 6. When antenna 1 is to be adjusted, output voltage U.sub.A is initially very low, so that the 1000-Hz package of pulses I' will follow one another very rapidly. As the optimal orientation is approached, pulses I' will be heard at constantly longer intervals apart until, depending on the design of voltage-to-frequency converter 3, they will no longer occur. One advantage of the invention is that even personnel that are not highly trained or even trained at all will be able to adjust the antenna because an acoustic signal is more definite and easier to evaluate than the difficult-to-read deflection of a needle on a scale.

FIG. 2 is another block diagram illustrating the invention. Whereas the signal voltage from the constantly vibrating oscillator 5 in FIG. 1 is forwarded through controlled switch 4 in synchronization with the pulses from voltage-to-frequency converter 3, FIG. 2 illustrates another way of generating package of pulses I', wherein oscillator 5 itself is activated in synchronization with pulses I through a control input terminal C' and a switch B.

FIG. 3 is a detailed circuit diagram of the variant illustrated in FIG. 2.