Skanti TRP 5000, Инструкция по эксплуатации

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TEST ALARM and TRANSMIT ALARM, and can be started by
pushing the ALARM
START push-button that a12 V to terminal 2c. Via the voltage
divider R32 and R33, a keying signal is applied to the Key Selector. The
2Hz Astable Muitivibrator starts and supplies base current to TR6 and
TR11 alternatively. The audio signal from the oscillators is, via the
Tone Keyer, applied to the l.4MHz EXCITER /232\ and, via the Side Tone
Keyer, applied to the receiver audio amplifier.
In the Al-mode the 1.5 kHz oscillator is started. The audio signal is
keyed in the Side-tone Keyer and the Tone Keyer which are both
controlled from the morse key. Capacitor C8 and adjoining components at
the gain control input of IC7 serve to shape the tone pulses correctly.
In the A2H-mode, the 2.2 kHz oscillator as well as the 1.5khz oscillator
are on. R54 is connected to ground in IC4, thereby reducing the peak
level of the audio signal at the Tone Keyer input to the same level as
when only one tone is present. The Side-tone Keyer is connected to the
1.5 kHz oscillator only, as TR12 is turned off by means of D24.
When the TUNE-button of the Transmitter Power Amplifier is activated,
terminal 18c is LOW. A2H is selected by means of Dl and D3, the
transmitter is keyed via IC2 pin 9, and the Side-tone Keyer is turned
off by means of IC,9
pin 1.
5.4.3 /235\ HARMONIC GENERATOR
There is one phase looked loop and its associated lock detector located
on this printed circuit board.
The reference frequency of 1.4 MHz for this loop is derived from the
TCXO, in order to accomplish the necessary degree of frequency stability
of the output signal from the Voltage Controlled Oscillator.
The fixed reference frequency of 1.4 M Hz is fed to one of the two input
ports of the Phase / Frequency Detector. The output from the loop
Divider is fed, via IC2, to the other input port of the Phase /
Frequency Detector, which in the case of a frequency difference between
the two signals will produce a DC-error voltage.
The purpose of the Low Pass Filter is to remove the pulses from the
output of the Phase/Frequency Detector, thus allowing only the DC-error
voltage to pass on to the vari-cap diodes of the Voltage Controlled
Oscillator.
The outputs of the VCO are amplitude regulated and fed to the RF-
TRANSLATOR /233\ and Pre-scaler respectively.
The division ratio of the Pre-scaler and the Loop Divider is controlled
by four outputs of the Band Decoder, IC4, which is again controlled by
the BAND-information stored in the MEMORY /238\.
Four other outputs of the Band Decoder select, via the Band Selector
IC1, the proper band of the VCO and the proper band pass filter of the
RF TRANSLATOR /233\.
The Lock Detector detects any frequency difference between the two
signals fed to the input ports of the Phase/Frequency Detector. When a
frequency difference is observed, the Lock Detector turns on TR9, thus
pulling down the KEYLINE to a low level voltage, as long as frequency
equality is not accomplished.
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