Teac EU-48, Руководство по обслуживанию

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3. TUNER
Either a PLL or a VST tuner is used as a tuner.
UV1316 (VHF/UHF) is used as a PLL tuner. For only PALM/N, NTSC M applications UV 1336 is used as the PLL tuner. UV 1315 (VHF/
UHF) is used as a VST Tuner.
Channel coverage of UV1316:
OFF-AIR CHANNELS CABLE CHANNELS
BAND
CHANNELS FREQUENCY CHANNELS FREQUENCY
RANGE (MHz) RANGE (MHz)
Low Band E2 to C 48.25 to 82.25 (1) S01 to S08 69.25 to 154.25
Mid Band E5 to E12 175.25 to 224.25 S09 to S38 161.25 to 439.25
High Band E21 to E69 471.25 to 855.25 (2) S39 to S41 447.25 to 463.25
(1). Enough margin is available to tune down to 45.25 MHz.
(2). Enough margin is available to tune up to 863.25 MHz.
Noise
Typical Max.
Gain
Min. Typical Max.
Low band : 5dB 9dB All channels : 38dB 44dB 52dB
Mid band : 5dB 9dB Gain Taper (of-air channels) : - - 8dB
High band : 6dB 9dB
Channel Coverage UV1336:
BAND CHANNELS FREQUENCY
RANGE (MHz)
Low Band 2 to D 55.25 to 139.25
Mid Band E to PP 145.25 to 391.25
High Band QQ to 69 397.25 to 801.25
Noise is typically 6dB for all channels. Gain is minimum 38dB and maximum 50dB for all channels.
Channel Coverage of UV1315:
OFF-AIR CHANNELS CABLE CHANNELS
BAND
CHANNELS FREQUENCY CHANNELS FREQUENCY
RANGE (MHz) RANGE (MHz)
Low Band E2 to C 48.25 to 82.25 (1) S01 to S10 69.25 to 168.25
Mid Band E5 to E12 175.25 to 224.25 S11 to S39 231.25 to 447.25
High Band E21 to E69 471.25 to 855.25 (2) S40 to S41 455.25 to 463.25
(1). Enough margin is available to tune down to 45.25 MHz.
(2). Enough margin is available to tune up to 863.25 MHz.
Noise Typ. Max. Gain Min. Typ. Max.
Low band : 6dB 9dB All Channels 38dB 44dB 50dB
Mid band : 6dB 10dB Gain Taper - - 8dB
High band : 6dB 11dB (off-air channels)
4.VIDEO SWITCH TEA6415C
In case of three or more external sources are used, the video switch IC TEA6415C is used. The main function of this device is to switch
8 video input sources on the 6 outputs.
Each output can be switched on only one of each input. On each input an alignment of the lowest level of the signal is made (bottom
of sync. top for CVBS or black level for RGB signals).
Each nominal gain between any input and output is 6.5dB.For D2MAC or Chroma signal the alignment is switched off by forcing, with
an external resistor bridge, 5VDC on the input. Each input can be used as a normal input or as a MAC or Chroma input (with external
resistor bridge). All the switching possibilities are changed through the BUS.
Driving 75ohm load needs an external resistor.
It is possible to have the same input connected to several outputs.
5. AM DEMODULATOR TDA9830
The TDA9830 is designed for AM-sound demodulation used in L and L’ standard.