摘要:
The specification discloses a method for connecting first and second transmitters, each containing its own oscillator, in parallel and to first and second aerial halves, respectively. A phase difference signal representative of the phase difference between the two signals generated by the transmitters and applied to respective aerial halves is generated. The phase of the signal generated by one of the transmitters is adjusted by means of a reactance circuit in the oscillator of the transmitter as a function of the phase difference signal. The oscillator of the remaining transmitters is permitted to oscillate independent of the phase difference signal.
摘要:
A device for the electro-optical display of the tuning of an electromagnetic wave receiver, such as a television or a radio, wherein the frequency of a received electromagnetic signal is measured and converted into a digital representation, which is applied to the input of a memory as the address of the various preprogrammed names of selected transmitting stations. The output of the memory is applied to select appropriate display elements of an electro-optical display and the selected display elements are then excited to provide a display indicative of the name or call letters of the transmitter station corresponding to the tuned receiver signal.
摘要:
The efficiency of the transmitter modulator stage of the type in which an anode current I.sub.a of the modulator tube varies as a function of the grid voltage U.sub.g in accordance with the expression I.sub.a =k.multidot.U.sub.g.sup.m, m.apprxeq.=1.5, in which k is a material constant is improved by introducing a deaccentuator into the transmitter circuit. The deaccentuator functions to cause the anode current I.sub.a to vary in accordance with the equation I.sub.a =k[h(U.sub.E).sup.n ].sup.m, where h and n are constants and U.sub.E is the signal applied to the input of the deaccentuator and n=1/m so that I.sub.a =k.multidot.h.sup.m .multidot.U.sub.E is a linear function.
摘要:
Slip-ring electrical contacts are avoided in a rotatable aerial or antenna of the type which is housed in a rotatable cage or basket having a supporting platform at the top of a mast, by constructing the electrical transmitting/receiving apparatus and the drive and control units for the rotating aerial at some region below the supporting platform for the rotating cage or basket, e.g., below deck in the case of a ship, and by transmitting the signal to or from the aerial by means of a wave guide concentrically arranged below and surrounding the axis of rotation of the cage, including a quarter wave joint surrounding the wave guide (with a clearance) on the platform, and connecting the wave guide to the aerial with the aid of a probe extending into the wave guide, two motor devices operating through differential gearing, all included in the region below the platform enabling the azimuth and elevation of the aerial to be determined.
摘要:
A method and apparatus for monitoring and controlling the anode power dissipation of transmitters. First and second signals proportional to the anode power input and anode power output are produced and subtracted from each other, thus resulting in a third signal proportional to anode power dissipation. The third signal is applied to a pair of threshold value actuators, with one threshold value actuator actuating transmitter tuning elements when an initial threshold level is exceeded, and the second threshold actuator switching the transmitter off when a second threshold is exceeded.
摘要:
A balancing loop including a housing inside of which is disposed a first conductor part having a first sublength and a second sublength, with the first sublength constructed as a coaxial line passing through the housing and having its inner conductor terminated inside the housing and connected to a second conductor part, and the second sublength extending from the termination of the inner conductor to the second conductor part to an output line. The second conductor part also has the first and second sublengths and extends spaced apart from and parallel to the first conductor part. The second conductor part has one side connected to the housing and the other side to another output line. The output lines connected to the first and second conductor parts thereby form two symmetrical output lines which lead out of the housing. At least one variable capacitor is arranged between the first and second conductor parts to tune the balancing loop over the operating frequency range. The characteristic line impedance of the first and second conductor parts and the first sublength are chosen such that the balancing loop can be tuned to a different frequency only by means of the variable capacitor, and without the need for changing the electrical length of the first sublength.
摘要:
For the simplified text or picture data signal transmission through a broadcasting system, an additional phase and/or frequency modulation is produced in amplitude modulated transmitters. In a preferred but relative slow transmission system, a frequency modulation (f.sub.1 -f.sub.n) occurs in a band width of .+-.25 Hz, whereby the transmitted quality of the simultaneously transmitted broadcast does not suffer. Depending on the type of transmission means, equipment and frequency (f.sub.o) of the carrier wave (T), this band width can be increased, for example during text transmission, in order to achieve a higher transmission speed. The system is compatible with AM mono and stero equipment as well as with printing and display installations of the electronic data processing and communication technologies.
摘要:
A method and apparatus for the automatic matching of a transmitter to an antenna is disclosed. A voltage signal proportional to the square root of the load impedance of the final stage of the transmitter is compared to a signal which is proportional to the square root of the nominal value of the final stage load impedance and the difference is used as the criteria for tuning a load coupling coil connecting the final stage of the transmitter to the antenna.