Frequency Response And Leveling Test; Rf Output Accuracy Test; Uncalibrated Rf Output Test; External Sine-Wave Modulation - HP 608E Operating And Service Manual

Section V Model 608E/F
e. Rotate frequency· control through entire limits
of range A. Depress and tune AMPL TRIMMER con-
trol when necessary during tuning cycle to keep the
rf output peaked.
b. Set FREQUENCY RANGE switch to range C.
c. Adjust frequency control for MEGACYCLES dial
reading of 70 MHz.
f.
Obs~rve power meter for minimum output dur-
ing tuning cycle. Indication should be a minimun!
of
+3 dBm over the range for the 60BE, and -3 dBm
across the range for the 608F.
d. Depress and adjust AMPL TRIMMER control for
maximum indication RF OUTPUT meter.
e. AdjustRF OUTPUT controlfor +7dBm (ATTEN-
UATOR CALIBRATED) indication on RF OUTPUT
meter.
g. Repeat steps e. and
f.
for frequency ranges B
through E.
f.
Set attenuator control to 0 dBm position. Power
meter should indicate 0 dBm ±l dB.
5-18. FREQUENCY RESPONSE AND LEVELING
TEST.
a. Connect signal generator in test setup illustrated
in Figure 5-5.
b. Set FREQUENCY RANGE switch to range D.
5-20. UNCALIBRATED RF OUTPUT TEST.
a. Connect signal generator in test setup illustrated
in Figure 5-6.
b. Model 608E should prOVide indication of -1. 8
dBm minimum on power meter. Model 60BF should
prOVide power meter indications as follows:
c. Adjust frequency control for a MEGACYCLES
dial reading near center of frequency range D.
d. Adjust attenuator control for a dial reading of
+7 dBm.
10t0215MNz: -1.8to+7.0dBm
215 to 400 MHz: +2.0 to +6. 0 dBm
400 to 450 MHz: +1. 0 to +5.0 dBm
)
4J~A
POWER METER
I
,
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TMER"'ITO~
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"OlJ~T
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t-
THERMISTOR
MOUNT
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608E!f
SIGNAL GENERATOR
e. Adjust RF OUTPUT control approximately one-
quarter turn from counter-clockwise stop.
f.
Adjust AMPL TRIMMER control-knob arrow to
eight-o'clock position and tune (-...
~~;
•..,....: -:''''t'ressing)
slowly clockwise. RF OUTPUT meter needle should
follow right and kick back suddenly. Stop tuning
AMPL TRIMMER control when needle kicks.
g. Adjust RF OUTPUT control for an RF OUTPUT
meter indication of +7 dBm (ATTENUATOR CALI-
BRATED).
h. Vary Frequency Control afew megacycles either
side of MEGACYCLES dial setting made in step C.
U RF OUTPUT meter needle does not lock on +7 dBm,
slowly readjust RF OUTPUT and AMPL TRIMMER
controls until needle remains at +7 dBm poSition.
Figure 5-6. Uncalibrated RF Output
Test Setup
,
i. Vary frequency control across frequency range
D. Peak-to-peak power meter variation should be
less than ±1 dBm over range and RF OUTPUT meter
needle shOUld remain at +7 dBm position.
j. Repeat steps c. through i. for frequency ranges A
through C and range E. The AMPLIFIER TRIMMER
adjustment for leveling on bands A through B typi-
cally is the initial setting of AMPL TRIMMERplu8 one
readjustment. Band E is typically the initial setting
plus up to three readjustments.
5·19. RF OUTPUT ACCURACY TEST.
a. Connect signal generator in test setup illus-
trated in Figure 5-5 omitting 8491A 10-DBAttenuator.
5-8
5-21. EXTERNAL SINE-WAVE MODULATION
AND MODULATION METER TEST.
a. Connect signal generator in test setup illustrated
in Figure 5-7.
b. Set FREQUENCY RANGE switch to range A.
c. Adjust frequency control for MEGACYCLES
dial reading of 15 MHz.
d. Adjust oscilloscope gain for envelope amplitude
of 5 cm peak-to·peak.
e. Set MODULATION switch to EXT AM position.