Skanti TRP 5000, Инструкция по эксплуатации

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When "2182 kHz" is selected by means of the BAND switch the information
is HIGH on al] four input leads from the BAND switch. In that case the
output from 1/2
IC2, pin 8, is HIGH and as terminal 7 is open and thus
HIGH too, the output of 1/4 IC1, pin 11, is LOW, telling the Exciter to
select 2182 kHz. The light emitting diode Dl will show constant light.
5.6.4 /254\ VOLTAGE REGULATORS
The Grid Voltage Regulator consists of two integrated circuits IC1 and
IC2 that operate as zener diodes having a very low temperature
coefficient. The actual grid voltage is set by means of the variable
resistor R1.
The screen grid voltage of the power amplifier tube Vl is fixed and
determined by two 150V zener diodes 250 Dl and 250 D3. In order to be
able to equalise the currents of the two tubes, the screen grid voltage
of V2 is made adjustable. The zener diodes 250 D5 and 250 D6 are
connected to a voltage-regulator containing transistor 250 TR1, the
collector voltage of which can be set by means of variable resistor R3.
The 6V filament voltages of, the power amplifier tubes has to be
controlled within very narrow limits to obtain maximum tube life. This
is done in the Filament Voltage Regulator. In order to reduce current
consumption the filaments of the two tubes are series connected, which
means that the voltage of each tube has to be control- led. The
regulator of V2 consists of the NPN darlington transistor 250 TR1 in
connection with the zener diode D4 and resistor R15. When the voltage of
the filament reaches 6V, the transistor starts to conduct and shunts the
filament by which the voltage is kept constant. The regulator of V, is
identical except the transistor is a PNP darlington. The collector
currents of the two transistors pass the diodes D5 and D6, and the
voltage across these diodes is applied to a current regulator consisting
of TR1 and 250 TR2. TR3 serves to limit the peak current.
5.7 Circuit Summary, 24V DC Power Pack P5000
5.7.1 The circuit diagram is divided into a wiring diagram On page 8-99
showing the interconnections between the printed circuit boards of which
the Power Pack is composed, and circuit diagrams of the individual
circuit boards. The block diagram on page 8-62 illustrates the operation
of the Power Pack.
5.7.2 Filament supply for the transmitter power amplifier output valves is
obtained directly from the battery, while the remaining necessary supply
voltages for transmitter Power Amplifier, Exciter and Receiver are
generated in converters. Converter transformers give full isolation
between the battery voltage and the chassis, permit- ting these to be
earthed without causing the supply leads to be earthed.
5.7.3 Low tension voltages for Exciter and Receiver and negative grid voltage
for the Transmitter Power Amplifier are generated by the LT -converter
followed by rectifiers and stabilisers.
The LT-converter frequency is determined by an RC-coupled oscillator
followed by
a bi-stable muitivibrator.