How To Adjust - Yamaha CT-7000 Service Manual

TERMINAL TO BE
ADJUSTMENT
STEP
ITEM
INSTRUMENT REOUI RED
13
Muting Level Antenna terminal (300.n)
I FM signal generator
98MHz/30dBI'
Modulation 400Hz/30%
mono
Fixed output jacks (L, Rl
Oscilloscope, Electronic
voltmeter
14 Muting Level
Antenna terminal (300ll)
II FM signal generat o r
98MHz/30dBI', 10dBp
Modulation 400Hz/30%
mono
Fixed output jacks ( L, R)
Oscilloscope, Electronic
voltmeter
15
Signal Meter Antenna terminal (300ll)
Set FM signal generator
98MHz/60dBI'
Modulation 400Hz/30%
mono
1 6
Auto B lend Antenna terminal (300ll)
Check FM signal generator
98MHz
Modulation 1 kHz/1 00%
stereo
Fixed output jacks (L, Rl
Oscilloscope, Electronic
voltmeter
17 IHF Antenna terminal (300ll)
FM signal generator
Sensitivity
Check 98MHz
Modulation 400Hz/100%
mono
18 Dial Pointer Antenna terminal (300ll)
Set FM signal generator
90, 98, 106MHz
NOTES
1. If the required values in Step
after the muting level is set to.
changing R214 &
shown in the figure to the right. Then carry o ut
all steps after Step
2. When carrying out the IHF sensitivity check in
Step 17, if the results do not satisfy the require·
ments adjust each
and each trimmer
mum sensitivity. For this adjustment, however,
first repeat the adjustments and checks beginning
1.
with Step
3. When the power switch is off, if
meter does not indicates
ically to this point via the adjustment hole on
the back of the meter. Then carry out the check
1
in Step again.
&
CONNECTED ADJUSTMENT
IF circuit board
Muting Adj.
Same as Step 13.
Control circuit
board
Meter Adj.
Dial pointer
14 cannot be met
1 0dBJ,t , correct by
270 in the IF circuit board as
15.
&
RF pack core (LA LR1-5),
( T CA & TCR1-5) for maxi­
the center
"0", adjust it mechan­
RATING OR

HOW TO ADJUST

STANDARD
Turn slowly from L to Once set, dif·
R and set at point terence from
where output begins. signal fed b y
FM S G must
be 30dBI'
6dB!'
Set for 30dBI' 6d Bl' at 30d Bl'
±
Muting VR.
Set for 11dBp SdBI' at 10dBI'
±
Muting VR.
Set so that the needle
60
±
deflects to "60" on the
meter.
After FM SG output
Operation
reduced, check change
Level
in separation and final
1:60dBp±
separation. 10dBp
11:40dBp
10dBp
Separation
1:14dB
3dB
11:8dB±3dB
Check antenna input
8dBJ,t (2.5J,tV )
when distortion ratio is
(6dBJ.!
-30dB (3.2%).
(2.0J,tVII
Set the dial pointer so
± lmm
that it is at the correct
dial location for each
frequency.
CT-70 00
REMARKS
Muting VR=30dBI'
±
If these values can·
not be obtained,
check the Note 1.
5
±
±
If these values can·
not be see Note
met,
2.
98M Hzst:andard
19