Axcera INNOVATOR, Инструкция по эксплуатации

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UHF Analog Driver/Transmitter/ Chapter 2, System Description,
Translator Maintenance & Remote Control Connections
LX Series, Rev. 3 2-3
external switching by placing jump er
W11 on J29 between pins 1 & 2).
The UHF Receiver converts a low level RF
input signal to an IF frequency of 44 MHz,
filters off any unwanted out of band energy,
and normalizes the level so that it can be
applied to the IF processor assembly. It
consists of three boards. The RF input is
applied first to the UHF preamplifier board,
which filters off out of channel energy and
amplifies the input signal. The RF output is
applied to the Mixer/PLL board, which
converts the signal down to an IF frequency of
44 MHz. The IF output is applied to the IF ALC
board, which amplifies the signal, filters off
any unwanted out of band energy and
controls its own IF gain to make sure that the
IF output level is constant.
There is also a provision to apply +12V to the
RF input center conductor to power an
external preamplifier.
CAUTION: Do not hook up the RF input
to any test equipment with the DC bias
applied. Always move the jumper
W1
on J2, on the UHF Preamplifier
Board, to the Bias off position, between
pins 2 & 3, to prevent possible damage
to the test equipment.
Table 2-2. Receiver Front Panel Switch
SWITCH FUNCTION
MAN/AUTO ALC
SW1
When Manual ALC is selected, the level is set by the Manual
ALC Pot R57 located on the mixer/PLL board. (
NOTE : The pot
is factory set and needs no adjustment by the customer).
When Auto ALC is selected, the level control circuit will
automatically increase or decrease the ALC to maintain the
desired output level.
Table 2-3. Receiver Front Panel Status Indicators
LED FUNCTION
PLL1 Fault DS6 Displays the status of the Local oscillator PLL
PLL 2 Fault DS8 Displays status of optional input frequency correcting PLL
DC on center conductor DS4 Displays whether or not DC is applied to the RF input center conductor
Man ALC Gain DS7 Displays when ALC is switched to Manual bypass
ALC Fault DS5 Displays ALC status
Table 2-4. Receiver Front Panel Control Adjustments
POTENTIOMETERS DESCRIPTION
Manual Gain R57 Adjusts the gain of the receiver when the ALC is bypassed.
A/V Ratio R50 Adjusts the ratio between the visual and aural carriers.
Table 2-5. Receiver Front Panel Samples
SMA CONNECTORS DESCRIPTION
Receiver IF J13 Sample of the IF output of the IF ALC Board.
Receiver LO J2 Sample of the LO generated on the UHF Mixer PLL Board.