Table of Contents
Advertisement
MAINTENANCE
WJ-8718-19/FE HF RECEIVER
Test Point
E15
Ql-D
Ell
E12,E13,E14
4-20
4.
Energize the receiver and tune to 30.00000 MHz.
5.
The frequency counter should indicate 190.0000 MHz.
6.
Tune
the receiver
in
10
MHz increments to
90.0000
MHz.
The
frequency
counter
indication
should
increment in 10 MHz steps to 260.0000 MHz.
7.
Remove
the frequency counter and connect the RF
voltmeter. The RF Voltmeter should display a level of-
2 dBm.
8.
If the signal in steps 5-7 is incorrect, check the Test
Points given in Table 4-6 with an RF Voltmeter and
high impedance probe. When a faulty signal is
encountered, replace the key components indicated and
repeat the Checkout Procedure.
Figure 6-5, VCO
Schematic Diagram should be referred to if additional
signal tracing/fault isolation is necessary.
9.
When the VCO has been repaired and is operating
satisfactorily, deenergize the receiver and disconnect
test equipment, if no further tests are to be performed.
Table 4-6.
VCO Fault Isolation Chart
Normal Signal
+3 Vdc
100 mV sine
100 mV sine
0 or +5 Vdc
Key Components
Synthesizer
Ql
Q2.Q3
Dig. Control
Comments
Receiver tuned to 42 or 76.5
MHz.
VCO
1st LO out
Refer to paragraph 3.4.2 and
verify the TP's while tuning
from 30-100 MHz.
Advertisement
Chapters
Table of Contents
