Honeywell XK516D1 Maintenance Manual page 62

The Core software provides additional power-up self-tests and the ADP Data Link
functions. These functions include such things as searching and logging onto HF
Data Link channels, processing uplink and downlink packets, and Data Module
built-in-tests/fault reporting. The ADP also maintains a database of HF ground sta-
tions that are used to tune to known data frequencies when logging onto the HF Da-
ta Link network.
(3) Power Amplifier, A3
(a) Amplifier Board, A31
Amplifier Board, A31, is composed of a low-noise 1st amplifier stage with amplifica-
tion of about 16dB, a PIN diode-controlled, voltage-controlled attenuator with an ad-
justment range of 0dB to 35dB and a 2nd amplifier stage with amplification of about
16dB. The amplifier train is completed by a series-connected preamplifier with an
amplification of about 22dB and a final pull-push stage with class A/B operation with
an amplification of about 18dB. Ref. Fig. 19 for block diagram.
With an input Level of –7dBm
maximum of 125W continuous wave (+51dBm) or 400W + 0.5dB PEP (+56dBm +
0.5dB).
The RFIN (X330) input signal is supplied via tubular sheathed cable, W1, to T/R
switch, K1. Choke, L18, is used to smooth any direct voltage peaks occurring at the
input. Relay, K1, has the function of connecting either the output signal of the RX
amplifier to the linking input (X330) for receive purposes, or the linking input (X330)
to the amplifier train for transmission purposes, depending upon the TRAMP 5.3V
logic signal (X2.42). In this connection, relay, K1, is controlled by transistor, V17.
R14 operates as a pull-down resistor. VI6 and C42 provide protection against in-
duction peaks.
The RFREC receive signal from Harmonic Filter, A32, (present at X98) is amplified
by about 6dB with the transistors, V250, V251, which form the RX amplifier. The op-
erating point of transistors, V250 and V251, is set by resistors, R261, R250, R251
and R262, R253, R252. C254, R254, and C255, R255 are used for thermal com-
pensation purposes. C250, C251 and C252, C253 are coupling capacitors. Diodes,
V260, V261, are used to protect the base of V250 and V251 from overvoltage. The
bias voltage of +15V and –15V is smoothed by electrolytic capacitors C261, C262,
and filtered by R258, C256 and R257, C257. The RF output signal of both amplifier
branches is combined by transistor T6. For compensation purposes, the output is
wired with R258, C260. C258, C259 are used as coupling capacitors.
The RF input signal is supplied to transformer, T2, via coupling capacitor, C44, and
the matching network, consisting of C12, R27, R60, C48, and L201. The input im-
pedance at the RF input (X330) consequently amounts to Z = 50
the entire frequency range of 2MHz to 30MHz.
The RF signal is applied via series resistor, R61, and coupling capacitor, C95, to
transistor, V4, which is reverse coupled with C6, R10 to optimize the frequency re-
sponse. The drain/source voltage of the 1st amplifier stage is +15V, which is con-
nected by V15 and V19, depending upon the OPON 5.3V logic signal (X2.48) and
smoothed by C14. This voltage is supplied to transistor, V4, via filter section L200,
C10. The gate/source voltage is set with potentiometer, R202, via voltage divider
Rl9, R25, choke, L205, and diode, V201. Zener diode, V202, provides overvoltage
I.B.1516A
Honeywell
COMPONENT MAINTENANCE MANUAL
PART NUMBER 964-0452
±
3dB, the output power of Amplifier Board, A31, is a
23-12-01
Ω ≤
, S 1.5 across
Page 53 Page 33
Mar 30/01