Service Adjustment - Sharp 29RX5 Service Manual

SERVICE ADJUSTMENT
PIF/AFT/AGC ADJUSTMENT
f*~iffiJ~
PIF / AFT/ AGCI¥.J
iJj!!ij~
1\)1\)
<0<0
:Il:Il
XX
COC1J
10kO
- 1.5dB ± 0.8dB
100kO
~I&U
-c
001
E-9~iIil:
002
750
s
1000p
"'~~l!l~
1000p
o-I~
2.
ttJ~t'iH~~VCOI3 J%i:~~~
:T203 (Tl03)
1..
Mjcttl~~~w: tl:l7C~0
2. X'tIC20l (IClOl
)~"I$lI
(4) (IF ACC
)Jil[tJll1l:i:JiE~EEo
6.0+0.lV TP202(TPI02)
3.
jlH5i:iil;;;\;~EEitl9!tl;!li:IC201
(ICIOI)"I $lI (20) (PLL FIL)
~1f.i:JiE~EEiilo
TP203(TPI03):~0.007V~~~IOkHz
*&H~~Jili'iJ~:lrlVH~.ra31!L~~~iil;;;\;~EErr
0
4.~~i!tJll~IC20l(IClOl)"I$lI(4)~1l:i:JiE~EEo
5.
fi§A.7C~. ~1&E-12!Ji!jBI!1i3%
0
(AFT9t~*f;lJ:I1t~at ,1i4~1&!Ji!jf~lt!j~:i'E~224.
25MHz)
6.
~~1t;;;\;~EEit~IC20l
(IClOl
)~"I$lI(20)o
~'PT203
(Tl03).
~~EEiilJ2s~~3 .I.iiiPJTl9!~:!ittl:l~~iilo
$ilfm:15iI :+0.015V(20kHz)
1.
~i~~IFT(~i~)~~~:TU20l(TUlOl)
1. T7'Gfil/%\'iiAi¥.Jl'll:i&:f*;;i5"F.
1l!~l\UBH
l'll:i&E-9~l1itli!!%z:t!t;;!;i. ~'PPLLf&!!:L
2.l'll:f.3m~llifl\'ii l!l~I!l!lT~lWfl5'i:~l'll:~~
(M~f.3m).
3. ~r,HI!)iHU~~ l!l !\!ljl-j980d81l
v.
4.l'll:IlfiJJ2l'1I!!.lt('I!l';g~!lJi:fli¥.J1ll;~JHJtj~Ht;
.!A!.
001)T~lWfl"'~\'iil!l~. (Rfi'€!iiHtT~
l\'!ifl"'~~l!l~).
5.
RM~ El ~~~!!i!tlJRF
AGCi¥.J !\!.ffi:il!ITO:3?:
6V~
i¥.J .!;IJlt%::r:l'll:Mzfl'LIL
6.
N~~l'li'fl"'~!!.ltI!l!lJ9T~!lJi:%~3[002J9T~
i¥.JJjIlI,laJ!*.
~~:~~~~~~. ~~~L~Mfl~~W
1iJ:fi •
- 1.5dB
:l:
O.8dB
10kn
100kn
Oscilloscope
Fig. 1.
E9CH
1000p
o---I~
Fig. 2.
1. Disconnect the antenna from the tuner antenna terminal.
2. Apply DC voltage at pin (4) (IF ACC) of IC201 (IC101).
6.0 +0.1 V TP202 (TP102)
3. Using a digital voltmeter, measure the DC voltage at pin (20) (PLL FIL) of IC201 (IC101).
TP203 (TP103):About 0.007 V corresponds to 10kHz.
• Prepare a digital voltmeter capable of reading down to the third decimal place.
4. Remove the DC voltage from pin (4) of IC201 (IV101).
5. Reconnect the antenna and receive the E-12CH signal. (With the AFT off, set the receiving frequency to
224.25 MHz.)
6. Connect the DC digital voltmeter to pin (20) if IC201 (IC101). Adjust T203 ( T103) to get the voltage
measured in the above step
@.
Allowable error: +0.015 V (20 kHz)
2.
vco
ADJUSTMENT: T203 (T103)
1. Get the tuner ready to receive the E-9CH signal,but
with no signal input. Adjust PLL data.
2. Connect the sweep generator's output cable to the
tuner antenna. (RF sweep)
3. Adjust the sweep generator's output level to
80dBIlV.
4. Connect 1he responce lead (use a low-impedance
probe with wave detector; see Fig.t.) to the tuner's
IF output terminal.
(This terminal must have the probe alone con-
nected.)
5. Set the RF AGC voltage to 0-6V with no contact
with waveform.
6. Adjust the tuner IF coil to obtain the waveform as
shown in Fig.2.
Note: Be sure to keep the tuner cover in position during
this adjustment.
1. TUNER 1FT (preset) ADJUSTMENT: TU201 (TU1 01)
IF-oUT
...
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