DE2824894C2 - Tunable frequency lock - Google Patents

Description

into which the coaxial cable feeding the reception frequencies is plugged. Above the cable entry socket 3 in the fastening part 2 made of plastic there is a bore through which the setting of the built-in variable capacitor 7 of the frequency lock according to the invention can be changed, for example with a screwdriver.

This hum possibility according to the invention, which is easily accessible from outside the receiving device the frequency lock can be achieved with relatively little effort that only the desired Receive frequencies in tuner 1.

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Claims (1)

1 2 bar. With this structure there are no measures for the Claim: required electrical contact protection specified, nor is the application of a frequency lock to the Tunable frequency lock with a suction suppression of unwanted frequencies and their circuit, which has a variable capacitor on- s touch-safe arrangement on the tuner and an input socket for the supply Tunable frequency lock is built in according to the Oberbegnff of the television set, in particular to develop pilot frequency patent claim, which is easily accessible from outside the quenzsperre for cable television tuner for pilot frequency television receiver, but the frequencies in the frequency range between 70 MHz and io corresponding VDE regulations regarding the required ! 20MHz, characterized in that such electrical contact protection is met
the suction circuit (6) with the changeable condensate. According to the invention (7), this problem is solved on an insulating material plate (8) which is galvanically separated from the television chassis by the characteristic features of the patented device. and between the input socket (3) and one of the channels the input socket (3) for galvanic input and, due to its structure, is provided on a separate separation on a plastic-made adhesive plate from the chassis of the television fastening part (2), which is separated on a wall 20 or tuner. There is also a free one Touch (1) of the tuner is attached that a hole is provided in the attachment of the adjustable part (2) assigned to the suction circuit, through which the capacitor is prevented because the capacitor only allows the capacitor (J) to be adjusted from the through a hole made of insulating material back (9) of the television from changeable fastening part accessible I is an actuation or is 25 Touching the capacitor is therefore only possible through conscious action, whereby access to the Unintentional touching of the rear of the television or adjustment is made even more difficult, thereby additionally increasing the protection against accidental contact. The invention relates to a tunable frequency adjustment of the suction circuit as an independent component according to the preamble of claim 1. half of the tuner also allows retrofitting In the case of television receivers for cable television, the frequency lock function does not interfere with the interior of the with the reception frequencies also pilot frequencies tuners high frequency detuning by change This means that the mechanical structure transmitted via the cable to the television receiver cannot be defeated. These pilot frequencies that fear when setting up and at 35. Maintenance of the systems for setting the RF levels. An embodiment of the invention is shown in FIGS. 1 Depending on the manufacturer, they are shown on a frequency im and 2 and are explained in more detail below Area placed between 70 and 120 MI Iz A pilot fre- It shows quenzsperre must therefore in the above-mentioned area Fig. 1 is a side view of a tuner with cable input be tunable and will be tuned with the installation of the television channel and built-in tunable frequency lock, receiving device from the customer service advisor individually F i g. 2 is a plan view of a section of a TV set back panel with built-in tuner, matched to the pilot frequency used in each case With a known frequency lock for a tuner cable input and setting option of the tunable of a television set (DE-OS 25 07 607) is connected to a frequency lock. 45 On the tuner wall 1 is a plastic made of plastic. zen a blocking circuit is galvanically connected, after the tes fastening part 2 with the built-in cable A suction circuit with a variable capacitor attached in the output socket 3 Usually get the Form of a capacitance-varying diode for suppressing reception frequencies from the cable input socket 3 kung undesired frequencies is switched on via the leads 5 to the tuner input isolator The connection line from the blocking circuit to the suction circuit is 50 4, which serves as electrical contact protection in to an oscillating circuit coil to select the respective tuner 1. desired receiving channel galvanically connected. Like F i g. 1 shows is between the cable entry Both the suction circuit and the oscillating circuit coil are the gal- ling socket 3 and the tuner input isolating element 4 vanisch to the chassis of the tuner and thus the remote-inventive tunable frequency lock with the vision device connected. A galvanic separation 55 suction circuit 5 and the changeable capacitor 7, between the input socket and the chassis is thus which are arranged on an insulating plate 8, contrary to the existing VDE regulations not installed given. The tuner input isolator 4 is used for galva> - ' In addition, there is a frequency lock for a tuner to see the separation of a coaxial cable via the Nes television set known (DE-GM 18 28 149), in the eo cable input socket 3 the tuner 1 supplied reception an insulating plate on a wall of the tuner and is used as an electrical contact is stigt. The insulating sheet has separate entrance protection according to the VDE regulations for each Sockets for the connection of a VHF antenna and a radio or television receiver ner UHF antenna and a switch with which ben. either the VHF input socket or the IF output 65 In Fig.2, a section of the rear wall 9 is one output of the UHF tuner to a VHF tuner is shown, in which the tuner is connected can be switched. The input sockets and the switch 1 with the mounting part 2 is installed. In the middle are operated from the rear of the television set this Fi g. 2 shows the cable entry socket 3,