Honeywell
COMPONENT MAINTENANCE MANUAL
PART NUMBER 964-0452
I.B.1516A
Mar 30/01
23-12-01
(c)
Interface D, A9
Interface, A9, houses the serial ARINC inputs and outputs, as well as a number of
discrete input and output lines.
(8) ON/OFF Module, A15
The purpose of the ON/OFF Module, A15, is to provide an optional On-Off switching func-
tion to the Transceiver via discrete input MP-5D. It also provides the supply voltage for
the internal blower.
(9) Data Module (PN 964-0452-002, 012, and 022)
The Data Module consists of the Airborne Datalink Processor (ADP) Circuit Card Assem-
bly (CCA), A2, and the HF Modem CCA, A10. When the Data Module components are
installed into an XK516D1 HF Transceiver, they allow the radio to maintain all the func-
tions of the Voice version Transceiver, but in addition, allows the Transceiver to operate
in HF Data Link (HFDL) mode as specified by ARINC 753 and ARINC 635.
The Data Module implements the airborne side of the HF air/ground protocol including
the automatic frequency selection and data link establishment.
C. Detailed Theory of Operation
(1) Receiver/Exciter, A1
The Receiver/Exciter, A1, contains the entire signal path in the recieve direction, the
small-signal path in the transmit direction, and the synthesizer.
(a)
Synthesizer
The frequencies required for conversion in the receive and transmit paths are pro-
cessed in the synthesizer. These are the "1. osc.", a frequency that can be modified
in 100Hz increments from 42025 to 70024.9kHz for the first mixer, a fixed frequency
of 40MHz for the 2nd mixer, and a fixed frequency of 8MHz as the clock frequency
for the signal processor. In addition a 2MHz signal is generated for the assembly
self-test (BIT). All these frequencies are derived from a 10MHz crystal oscillator.
The data required to set the "1. osc." are input with active moduLe select 1 (MS1 =
LOW) via the bidirectional data bus (16 bit, 3 addresses).
1
Crystal oscillator
The crystal oscillator is a D-TCXO (digital temperature-compensated crystal os-
cillator) with a frequency of 10MHz. The frequency deviation is less than 0.5ppm
in the temperature range from –40°C to +85°C. The crystal oscillator is supplied
with a voltage of +12V by fixed voltage regulator, N11. Frequency adjustment is
effected by potentiometer, R239. The output frequency (5V CMOS level) is di-
vided by 5 and then by 2 in divider, D5-B. The 2MHz signal is required for the
self-test; the 1MHz signal to process the frequencies.
2
Loop 1
The fixed frequencies of 40MHz and 8MHz are produced in this Phase-Locked
Loop (PLL ). Ref. Fig. 9 for block diagram.
The Voltage-Controlled Oscillator (VCO) is essentially composed of transistor,
V64, and the oscilLator circuit, which can be retuned with tuning diode, V61. The
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