Advertisement
tentlometers cannot be set for the
proper
voltage
readlngs
, flrst
check
the appllcable
potentlometer. If the potentlometers
are
operatlng properlyr r€place fC-l.
To
replace the fC, cllp off all of
the
leads as close to the
body
of the
module
as
posstble.
Then
unsolder
and remove
one
lead
at a tine, belng careful not to put
the
prlnted wtrtng pattern
away
from the
board.
GAIN
ADJUSTX{ENT
PNOCEDUNE
If potentiometers
R5,
R7,
R9
or fC-I
are ever replaced, lt will
be necessary to
readjust
R5,
R7 and R9. Adjust the poten-
tiometers aceording to the following pro-
cedure
:
EquipTnent Requlred
l.
An audio
oscillator with a
lOO-IIz
output.
2,
An
AC-VWM.
Procedure
I.
Connect
the audio oscillator
and the
VT\IM
to JtOOl
and
JIOOZ
on the
Test
Amplifier.
2.
Turn
R1O01
on the Test Amplifier fully
LBr
-4097
clockwlse to the
CALIBRATE
positioor
and
place the
GAIN
control in the
XI
pos
1t
lon
.
3.
Apply a
lOO-Hz,
.04-vo1t
RMS
signal to
the
ampllf
ler.
4.
Now
connect the
VTVM
to output
j
acks
J10O3
and
JLOO4
on the Test Amplifier,
and adJust
R9
for a meter reading of
.
04
vo
lt
m{S.
5.
P1ace GAIN
control Sl0Ol to the
X10
positlon
and adJust
VI for a
meter
readlng of O.4 volt
FUUS.
6.
Place
GAIN
control
SIOO1
in the
XsO
posltlon
and
adjust
R5
for a
meter
reading of 2.O volts
RMS.
CATIBRATIO]I
PROCEDURE
If desired, the output of the
RF Probe
can be
callbrated in millivolts.
Calibrate
the probe as follows:
Equipment Required
1
.
Signal Generator
(U-560
or
equ
j-va
len t
)
with a
Type N male
to
BNC
female adapt-
or
and
a
Type
BNC
Tee cotlnectof
,
and
a
50-ohm
load.
2.
Test Amplifier
and
RF
Probe.
UAINIENANCE
GE
TEST
SET
'mr,,sw'l
9
ffi
SIGNAT
GENERATOR
:cL
:@
offi
TYPE
''N"
MALE
TO TYPE
BNC
FEMALE ADAPTOR
TYPE
BNC
TEE.CONNECTOR
RF
PROBE
50-oHM
LOAD
TEST AMPTIFIER
Figure 3 - Calibration Test
Set-Up
Advertisement
