FREDERICK ELECTRONICS lSOOB1500B, Instruction Manual

Page: 39 / 71

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5.3 I NITIAL CO NTROL SETTI NGS
Initial settings of all front panel controls are listed be­
low. Unless otherwise stated, these settings should be maintained
throughout the alignment procedures.
POWER switch . .
.
. . .
OUTPUT LEVEL control .
RF GAI N control . .
AGC switch
· • . .
OSC TRIM control .
CRYSTAL switch .
.
.
.
. .
.
. .
.
.
. .
. O N
•
Maximum clockwise
. Maximum clockwise
RMT
. Center
. R
BA ND switch
. • .
. . .
.
. •
.
•
c
MHz control.
Bandwidth Switch
• . .
AM -SSB switch. .
. •
Approximately 9 MHz
. . 1 kHz
SSB
5. 4 BFO OSCILLATOR ADJUSTME NT (Refer to Figure 7-5.)
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1
The BFO oscillator outputs should be checked whenever it is
necessary to replace faulty components in one of the oscillator
circuits. Only the circuit actually affected by the replacement
must be checked; but, it is recommended that the complete pro­
cedure be performed since the test equipment is already connected.
The Model 1500B is often used with demodulators utilizing
a 2550 Hz audio center frequency. Since the standard audio out­
put is 2500 Hz, the BFO oscillators should be offset SO Hz to
produce the desired output. The BFO in S tep 2 should be adjusted
for a frequency of 9002.550 kHz and the BFO in Step 3 should be
adjusted for a frequency of 8997.450 kHz.
5-2
1. Connect Counter lead to TP2 on board N 0767; connect
common lead to chassis.