Honeywell XK516D1 Maintenance Manual page 65

Both the level of the RFIN RF input signal (X330), and that of the RFTRAN RF out-
put signal (X99) are monitored.
To measure the input level, the RFIN signal is applied via coupling capacitor, C98,
to transistor, V6. Transistor, V6, is connected to R177 to R179 as unity gain buffer.
Diode, V51, protects the base of V6 from negative voltages. The signal is passed
on to the peak rectifier formed by V44, R128, R168, C89, R160, via coupling capac-
itor C73. The rectified voltage is supplied to comparator, N2-A, and compared with
a voltage that depends on the OPON 5.3V logic signal (X2.48). Modules V45, R164,
and C88 serve to compensate the diode characteristic of the rectifier circuit with
V44. The OPON signal is supplied via diode, V47, and voltage divider, R161, RI69
to N1-A. R180, R162, and C84 are used to adjust comparator hysteresis.
For receive purposes, the voltage on the + input of comparator, N1-A, is pulled up
via resistor, R200, and diode, V52, depending upon the OPOFF 5.3V Logic signal
(X2.45).
If the RF input level at RFIN exceeds about –15dBm, then the SENSI 5.3V logic sig-
nal (X2.22) = LOW.
To measure the output level, the RFTRAN signal is divided at the output of Amplifier
Board, A31, by capacitive voltage divider, C65, C72, and rectified by peak rectifier
V5, C2, R5, and L17. The rectified voltage is compared at comparator N1-B with the
SPRFP voltage divided by voltage divider, R167, R181. R166 is used to adjust com-
parator hysteresis.
If the RF output signal exceeds 100
±
15W PEP, the SENS2 5.3V logic signal (X2.25) = LOW.
The amplifier board is cooled by an internal blower, which is switched with relay, K2.
R185, C115 are used to protect the contact of K2 from arcing.
Relay, K2, is controlled by transistors, V61 or V62, depending upon the BLON1
(X2.24) or BLON2 (X47.4) logic signals. V60 and C116 provide protection against
(b) Amplifier Control, A33
1 Introduction
Amplifier Control, A33, performs 2 primary functions. First, it regulates the out-
put power of the XK516D1 400W HF Transceiver, such that, operating under
normal conditions, the output power is kept constant at the nominal value.In this
connection, the Amplifier Control continuously receives information about the
forward and reverse power from the directional coupler located in Harmonic Fil-
ter, A32. Further operating parameters are also reported by Amplifier Board,
A31, which generally only result in a reduction in output power in the event of an
equipment fault. Ref. Fig. 20 for block diagram.
The second function performed by Amplifier Control, A33, is that of an interface
between Controller, A8, and Amplifier Board, A31, and Harmonic Filter, A32.
This includes the evaluation of data bus information, linking with signals from
Amplifier Board, A31, and Harmonic Filter, A32, and driving both these modules
on the one hand, and the detection of faults in the entire Power Amplifier, A3,
and their indication by means of the data bus to ControLler A8 on the other.
1I.B.1516A
Honeywell
COMPONENT MAINTENANCE MANUAL
PART NUMBER 964-0452
23-12-01
±
15W continuous wave, or is greater than 200
Page 56
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Mar 30/01