HP 85662A Troubleshooting And Repair Manual page 293

IF-DISPLAY SECTION
LOG |F-VI DEO
AMPLIFIER-FILTER MOTHERBOARD „ „ _
[A4A3 " I FA4A10" I r"A4A2
LOG AMPLIFIER-DETECTOR
A4XA3P2 A4XA2P2
21.4 MHz
+5dBm ±2dB*
2 > — -
L. .J
IF CONTROL
fA4A9
"~l
LG20
> 1 !
LOG/LIN
> 13
L.
A4XA9P1 A4XA2P2
■J L.
8««
7 <
9 <
©LOG AMPLIFIER STAGES
STAGE 6
+ 12VF
STAGE 7 STAGE 8 STAGE 9
Q21,Q22
©PIN DIODE ATTENUATOR
Q19.Q20
l$> ®
<7
A
LG20
-wv—> t
©CONTROL
LG20
SWITCH
LG20
Q7
CR26.27
Q10
•12VF
LOG/LIN
.J l_.
?0 *
LOG/LIN
SWITCH
V * h f JQ9 I
V * ^ -12V
-12VF
Q8
V
Q5
CR28.29 ,.
f>
©DETECTOR
Q2
©TEMPERATURE DEPENDENT
^TOR
•
-12 VTV REGULATOR .
6
■12V +2V
PIN DIODE
Q11 ATTENUATOR
REGULATOR
ATTEN
REGULATORS
-7V +4V
-15VF
Q4
£>
0.9 +.05VDC
ZERO g
Q3
»l * f f
Q12.Q13
V V
©COUNTER OUTPUT BUFFER/
LIMITER
Q6 o
-H M-
IF-VIDEO
MOTHERBOARD VI DEO PROCESSOR
~ | [A4A10" " 1 [A4A1 "" " ~ l
^ 1
J1
A4XA2P1 A4XA1P1
I I
: i i
L.
J2
l
->
VIDEO
.J L.
W15 21.4MHz IF OUT
- ^ — < -22dBm ±3dB
TO REAR PANEL
COUNTER OUTPUT
W1S 21.4MHz
- Q < -28 TO -35dBm
TO FREQUENCY
COUNTER
. J
A4A2 LOG AMPLIFIER-DETECTOR, BLOCK DIAGRAM