-
the antenna circuit and peripheral circuits (Middle Plug (MP))
-
the power supply circuits (Bottom Plug (BP)).
(2) Characteristics The HF transceiver complies with the standards defined in ARINC 719. The transmission and reception of coded messages between the various control units (CFDIU, RMP) comply with ARINC 429.
R **ON A/C 001-049, 101-105, 151-199,
(3) Operation (Ref. Fig. 006) The unit is of modular design and consists of a receiver/exciter A1, a power amplifier A3, a power supply A4, an EMC filter A7, a motherboard A6, a controller voice A8, an interface 1 A9, a LED Board A5 and an ON/ OFF module A15. The 400 W HF transceiver XK 516 D1 is controlled via two ARINC 429 serial ports which are connected on the aircraft to the radio management panel. the 400 W HF transceiver XK 516 D1 is configured for control via ARINC words both with label 037 ("old" HF), and words with label 205, 206, 207 ("new" HF). The 400 W HF transceiver XK 516 D1 can be connected by means of two further ARINC 429 ports (receive and transmit) to an on-board central fault display system according to ARINC 604 or central maintenance system . The transceiver automatically detects to which kind of aircraft maintenance system it is connected.
1EFF : ALL 1 23-11-00Page 27 1 1 May 01/05 1 1 1CES 1
Transceiver - Simplified Block Diagram
Figure 006
R 1EFF : 001-049, 101-105, 151-199, 1 23-11-00Page 28 1 1 May 01/05 1 1 1CES 1 The antenna coupler FK 516 (part of the 400 W HF radio XK 516 D) is connected to the 400 W HF transceiver XK 516 D1 only by a coaxial cable. This coaxial cable carries the RF signal, the coupler power supply (+28 V), control data for the coupler and acknowledgements and BITE data from the coupler. The data transfer between the 400 W HF transceiver XK 516 D1 and the antenna coupler FK 516 takes the form of serial data telegrams via the inner conductor of the coaxial cable. In conjunction with antenna couplers of other manufacturers , the 400 W HF transceiver XK 516 D1 provides the necessary control signals in this connection, such as rechannel pulse, tune power and interlock excitation. the 400 W HF transceiver XK 516 D1 automatically recognizes which coupler is connected (antenna coupler FK 516 or other coupler).
(a) Not Applicable
R **ON A/C 051-099, 106-149, 201-299, 301-399, 401-499,
(3) Operation (Ref. Fig. 006A) The transceiver consists of five functional units: frequency control circuit, power supply, receiver-exciter, transmitter, synthesizer.
(a) Frequency control provides:
-BCD (Binary coded decimal) frequency information to frequency synthesizer
-frequency band information to the low-pass filter
-mode of operation to receiver-exciter
-rechannel detection signal to the antenna coupler.
A microcomputer decodes the ARINC 429 serial words.
The microcomputer controls the timing and distribution of the
decoded digits to the frequency synthesizer.
Frequency synthesizer generates 500 KHz, 69.3 MHz (USB) upper
side band, 70.3 MHz (LSB) lower side band and 71.8 to 99.7999 MHz
signals that are derived from 9.9 MHz frequency standard.
The receiver receives, amplifies and detects incoming AM and/or
USB/LSB signals from 2.0 to 29.9999 MHz.
The receiver enables reception of the audio data and SELCAL
modes.
The exciter section produces either USB/LSB or AM 2.0 to 29.9999
MHz signals.
The transmitter consists of a solid-state power amplifier with a
7-band low-pass filter.
1EFF : ALL 1 23-11-00Page 29 1 1 Aug 01/05 1 1 1CES 1
Transceiver - Simplified Block Diagram
Figure 006A
R 1EFF : 051-099, 106-149, 201-299, 301-399, 1 23-11-00Page 30 1401-499, 1Aug 01/05 1 1 1CES 1 The power amplifier amplifies the radio frequency input of 100 mW nominal peak envelope power (pep) to a 400 W pep/125 W average level. A band-switched lows-pass filter filters the output of the power amplifier.
(b)
Power supply (Ref. Fig. 007) The transceiver is supplied with three-phase 115VAC, 400 Hz power. One of the phases supplies the antenna coupler through the transceiver. The power supply generates filtered + 51VDC, together with four voltages. These are provided from filtered 28VDC for the other circuits and are + 20 V, + 10 V, + 5 V, - 12 V.
(c)
Receiver (Ref. Fig. 008) In receive mode, the antenna of the HF transceiver receives a signal of a frequency comprised between 2 and 29.9999 MHz. This signal is modulated in AM, USB or LSB mode. The signal from the antenna coupler is transmitted through the antenna relay to a bandpass filter. The filter covers the frequency range from 2 to 30 MHz. The filter output passes through a transformer to an attenuator. The AGC (Automatic Gain Control) circuit and RF sensitivity circuit control the attenuator. The signal is then amplified in a wideband mixer and fed to a first mixer. This mixer receives a signal from the antenna (2 to 29.9999 MHz) and a signal between 71.8 and 99.7999 MHz from the synthesizer. A 69.8 MHz frequency signal is then obtained from the mixer. This signal is filtered, amplified and fed to a second amplifier. This second mixer also receives a 69.3 MHz signal in USB and AM operation or 70.3 MHz in LSB operation. At the mixer output, a second intermediate frequency of 500 KHz is obtained. This 500 KHz signal is processed in two different ways depending on the mode of operation, SSB or AM.
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