SeaCom Dukane 42A12D User manual

03-TM-0038 REV 00 PAGE 5of 5
3.3.3. ADJUSTING FREQUENCY RANGE.
A. The frequency range for the Test Set is 30 to 45 kHz.
The audio output is tuned for approximately 3200 Hz.
B. Set the TUNING knob to the maximum frequency (45
kHz). Place an oscilloscope probe or frequency counter on
the output of the local oscillator circuit, pin 14 of U2. See
Figure 3.3.
C. Monitoring the frequency, adjust R16 for the maximum
L.O., approximately 42 kHz or as high as possible.
D. Set the TUNING to the minimum frequency (30 kHz).
E. Tune R22 for the minimum L.O., approximately 27 kHz.
F. Repeat steps C through E as many times as necessary
until both ends are tuned.
3.4. TEST SET SCHEMATIC DIAGRAM.
Figure 3.2. is the schematic diagram for the 42A12D Ultra-
sonic Test Set.
3.5. MAINTENANCE AND REPLACEMENT PARTS.
A. Tuning or Gain
1 control knob....................P/N 809-440-0004
B. GAIN control R13.......................P/N 601-315
C. TUNING control R23..................P/N 601-372
D. Battery.............................NEDA Type 1604A
BT1
9V
SW1
SWPOWER
R13
10K
C1
68 R1 33.2KR7 15KR5 68.1K
R6
221K
Q3
2N5086
C3
.01
Q2
2N5088
R29
75K
R9
68.1K
Q4
2N5088
C6
.01
C15
.01
R8
100K
L1
2.7MH
R17
750
R19
75K
T2
1408
L2
2.7MH
R30
2.7
C10
68
C18
68
AUDIOOUTPUT
R31
10 R32
10
LS1
SPEAKER
J2
C11
10 C12
330
C13
68
C14
.02 R20
10
C7
.1
C9
.047
R18
120
6
4
1
7
5
2
3
8
U?
LM386M
R11
6.8
R10
47.5K
R12
4.75KC8 22
C2
.01
R3
3.16K
R4
3.32KC4
22
D2
1N4005 T1
1408
Q1
2N5088
R2
150
D1
1N4005
Y1
TRANSDUCER
R24
2.00K
D4
1N4454
D3
1N4454 R28
7.15K
12
13 14
4
1
1U2D
LF444
R27
22.6K
5
67
4
1
1U2B
LF444
C17
470pFR26
56.2K
R25
56.2K
10
98
4
1
1U2C
LF444
R22
10K
R15
511K
R14
511K
C5
560pF
3
21
4
1
1
U2A
LF444
C16
.1
R23
100K
R16
50K
R21
47.5K
UNLESSOTHERWISE SPECIFIED;
1.ALL RESISTORSAREINOHMS,K=1,000,
2.CAPACITORSAREINMICROFARADS.
M=1,000,000,1/3WATT +/-1%.
NOTES:
Figure 3.2 Schematic Ultrasonic Test Set Model 42A12D
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