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odel654A
Section V
Model 654A
1ge
se
ttings.
readings are
low,
proceed to step d. (f all the
5-54. XIO RANGE ADJUSTMENTS.
readings are within tolerances, proceed to
step
f.
a. Connect the equipment as
shown
in Figure 5-15.
d.
Check
readings
a
t I, 5
and
lOon the dial. If
readings
are
close to proper value, proceed to step
b.
Set the 654A FREQUENCY RANGE
switch
to
y
e.
If they are not, perform the following:
XIO
and
FREQUENCY dial to
I,
other
controls as
)(
g
in Paragraph 5-50b. The
coun
ter
(set
to read
J) Place dial to clockwise position
.
period average)
should
indicate 100
±
3msec (10
±
0.3 Hz) and A2TP2
voltage should
be - 370
2) Remove the frequency dial knob and loosen the
±
40 mV; if ei ther frequency or A2TP2
vol
tage is
four
d iaI retaining
screws.
not within tol erallce
,
change the
value
of S2R2*
and S2RIO* simultaneously
(see
Table 5-4) until
3) Slip the dial to read I
with
a
counter
indication
the tolerances are mel.
t.
of I kHz (Frequency Range
J
K).
c. Check frequency
tracking using the set tings
and
rfonn only
4) Tighten the retaining screws and replace the
tolerances given in Table 5-2 for the Xl 0 range.
knob.
Moni tor A2TP2 vol tage which should remain at
-370
±
40 mV over the entire range. If necessary,
ns
during
e.
Set the FREQUENCY dial to 10. Adjust S2C2 and
to make dial track, repeat step b but
set
the
no move-
S2C8
alternately
until the
counter indicates
a
frequency
towards the upper
or
lower tolerance.
Figure 6-1.
frequency
of
10 kHz and A2TP2
voltage
is - 370
ther.) Also
±
10 mY. Then recheck
at
1
on
the dial. Work
5-55
.
XIM RANGE ADJUSTMENTS.
Jly must be
back
and
forth betw
ee
n I and lOon the dial until
botharenearorwithin the allowed limits. Recheck
a. Connect
the equipmen t
as
shown in Figure 5-15
.
step
c.
)6 prevents
completely
I) If S2C2 does not have sufficient range,
change
b. Set the 654A FREQUENCY RANGE
switch
to
tor a t least
the value
of
S2C3
*
(refer to Table 5-5). If S2C8
XIM and the FREQUENCY dial to 10,
other
does not have
sufficien
t range,
change
S2C9*
controls as in Paragraph 5-50b.
kwise posi-
2)
If
A2TP2
should
not
remain
- 370 mV
- - - - - - N O T E - - - - - -
first mark
±
20 mV over the en tire dial range, change
Adjust
A2CI
,
S2C6
and
S2C12. if
f the fixed
value of S2C 16
* or
S2C 13
*
to bring frequency
necessary, to
start oscillation.
luency dial
and
A2TP2 voltage within limits.
'ews.
After
c_ Adjust S2C6
and
S2CJ 2 (see Table 5-4) for a
f.
Check all
frequencies on
the X I K range according
counter indication between 10.1 and 10.2MHz(1
to Table 5-2. The voltage
at
I
and
lOon the dial
to 2% high) and A2TP2 voltage between - 0.38
V
should read the
same
±
10 mY. If voltage is not
e
5-15 and
and - OAO V.
within
limits, proceed to step e(2).
Iph 5-50b.
- - - - NOTE----
d. Set the FREQUENCY dial to 5;
counter
should
,8 and
J
O.
indicate 5,000 +1-65kHz. If not, perform the
~
are low,
Steps d,
e and f
interact with
each other.
following.
high
or
all
I) Note whether the
counter
indication is higher
or
lower than 5,000kHz.
5-53. XIOO, XIK
and
XIOK RANGE TRACKING.
2) Set the FREQUENCY dial to 10; if the
a. Connect the equipment
as
shown in Figure 5-15.
frequency of
step
I) was high,
adjust
A2CI to
Set the 654A controls as in Paragraph 5-50b.
increase the counter indication slightly: if the
frequency of step I) was low, adjust A2CI to
slightly
lower the
coun
ter ind ica tion.
b. Check frequency tracking
of
the FREQUENCY
dial uSing the settings and tolerances
given
in Table
5-2
for the XIOO, XIK and XIOK ranges. Also
- - - - - -
NOTE - - - - - -
moni tor A2TP2 voltage which
should
remain
While making this adjustment to A2CI,
Within - 0.3 to - 0.4 V over the
entiry
range. If
the
OSCillator
may
stop
oscillating:
necessary, pad S2C17* for XIOO RANGE
and
however, the adjustment to be made in
S2C I * and S2C 18
*
for X 10K RANGE for correct
step
3)
will start oscilla tions again
.
frequency and A2TP2
voltage
when the dial is set
to
10.
3) Readjust S2C6 and S2C 12 as in
step
5-5
5c.
5-15
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