CN1127968A

CN1127968A - Method for making frequency changer in cable TV

Info

Publication number: CN1127968A
Application number: CN 94111546
Authority: CN
Inventors: 蒋柏平
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-12-26
Filing date: 1994-12-26
Publication date: 1996-07-31
Anticipated expiration: 2014-12-26
Also published as: CN1045357C

Abstract

The frequency converter for cable TV is attached to ordinary TV set that has less number for channels received to receive more channels features that its input is divided into two, one being mixed with local oscillator's signal and then two-band strobed and mixed with another in UV-band mixer for outputting. Its advantages are low cost and working well.

Description

The facture of cable TV upconverter

What the present invention proposed is a kind of method of making the cable TV upconverter, belongs to the cable TV technical field.

Existing method, cable TV (hereinafter to be referred as CATV) terminal with each channel signals of pass respectively one by one with different local frequency signal mixings, be added to intermediate frequency amplifier and get medium-frequency TV signal, again with another local oscillator mixing once, be transformed on certain same channel of common TV function reception, watch with one of them channel of television set.Its product such as CATV station selector etc. are seen shown in Figure 2.The weak point of existing method is the multichannel signal receiving function that does not have in conjunction with utilizing general television set originally to have.And the product cost of making is higher, uses inconvenience.

The objective of the invention is deficiency at above-mentioned existence, proposing a kind of product that makes reduces cost significantly, improve performance, be convenient to satisfy people comprise the cable TV upconverter of all channel program demands that the CATV of additional channel program transmits with the general television set reception manufacture method.

Technical solution of the present invention: to each channel signals of CATV terminal, be divided into two-way earlier: the one tunnel with local oscillation signal through the frequency mixer mixing, local oscillation signal is decided appropriate frequency, the mixing of CATV additional channel is in UHF (hyperfrequency) TV band, mixing output is added to the UHF input of UV frequency range blender, can amplify with U section amplifier earlier, through UV frequency range blender high pass circuit gating; Another road directly is added to UV frequency range blender VHF (very high frequency(VHF)) input, mixes through its low pass circuit gating and with the UHF section, and the VHF of tv channel frequency configuration standard distribution, each channel TV signal of two frequency ranges of UHF are pressed in output.Can be convenient to general television set directly watches.

Accompanying drawing 1 is a block diagram of the present invention.

Accompanying drawing 2 is prior art block diagrams.

Accompanying drawing 3 is embodiments of the invention figure.

Among the figure 1 is also band pass filter, the 2nd of distributor, frequency mixer, the 3rd, local oscillator, the 4th, UV blender, the 5th, power supply, the 6th, intermediate frequency amplifier, the 7th, band pass filter, the 8th, adjustable local oscillator.

Below in conjunction with Chinese TV machine and 450MHzCATV system example the present invention is described in detail: at the CATV user side, general television set can watch all that generally frequency that CATV transmits is less than the i.e. signal below 12 channels of 223MHz, but all there is not receiving ability less than the general television set of signal of 470MHz (before 13 channels of uhf band) again greater than 223MHz, this section frequency band is referred to as additional channel, and the CATV system has all transmitted many programs in this scope.The present invention can make the CATV input signal be divided into two-way: the one tunnel with frequency more than or equal to the local oscillation signal source of 247MHz through the ring mixer mixing, be added to the UHF input of frequency range blender (UV3811) again, through its high pass select just to have obtained in the original signal greater than each additional channel signal of 223MHz with the frequency signal, promptly become uhf band television signal greater than 470MHz; Another road directly is added to the VHF input of UV3811, selects just to have obtained the i.e. original signal below 12 channels less than 223MHz through its low pass, mixes output with the uhf band television signal again.Can be convenient to general television set and both watch original VHF frequency band signals, can watch the additional channel program at uhf band again.To different CATV system and television receivers, can do to select separately to each signal frequency and circuit devcie etc. with reference to said method.

Adopt the present invention, can fall cost, improve performance, be convenient to satisfy people receive all channel programs of the CATV transmission that comprises the additional channel program with general television set demand.

Claims

1, a kind of manufacture method of cable TV upconverter, the invention is characterized in: to each channel signals input of CATV terminal, be divided into two-way earlier, one the road and the output of local oscillator all be added to the corresponding input of frequency mixer, local oscillator is decided appropriate frequency, the mixing of additional channel is in the UHF TV band, and the UHF input of UV frequency range blender is received in the output of frequency mixer, through the high pass circuit gating of UV frequency range blender; Another road directly is added to UV frequency range blender VHF input, mixes through its low pass circuit gating and with uhf band, and the VHF of tv channel frequency configuration standard distribution, each channel TV signal of two frequency ranges of UHF are pressed in output.