Rf input <1, 70 mhz input, Local oscillator 70 mhz – Tektronix 1705A User Manual
Page 198: 1705a spectrum monitor
12V
+11.8V
C109
5000PF
SHIELD CAN
REAR
PANEL
--- 25 dBm
70 MHz INPUT
5 dB PAD
J400
MIXER
--- 26 dBm
--- 32 dBm
--- 6 dB
(--- 1 dB)
3 dB PAD
--- 35 dBm
C299
4700PF
R398
150.0
VR398
6.2V
2
7
1
3
8
4 5 6
U296
NE5205
C298
.1UF
3 dB PAD
--- 18 dBm
(--- 8 dB)
--- 26 dBm
J890
<2>
A1
136--- BPF
J9
C389
10PF
C290
20PF
R393
13.0
R392
221.0
L391
163NH
L393
150NH
C292
20PF
R391
13.0
L389
150NH
20 dB GAIN
C295
4700PF
R292
221.0
R293
13.0
C395
4700PF
R291
13.0
2
4
6
8
7
5
3
1
U190
SBL--- 1
L195
163NH
L193
150NH
C196
39PF
C194
39PF
C192
22PF
1
3
2
5
4
T187
SHIELD
C198
.02UF
R299
22.1
L197
150NH
R298
121.0
R297
22.1
C199
22PF
75 OHM
70 MHz
INPUT
--- 20 dBm
LOCAL OSCILLATOR
70 MHz
NC
NC
NC1
1
4
4
3
1
3
2
5
U283A
CA3102
NC
8
7
11
9
6
10
12
U283B
CA3102
C181
560PF
R184
510
R183
7.50K
R281
30
R182
1.82K
C180
560PF
R181
3.92K
C281
100PF
C282
470PF
4T
L280
45NH
1T
L284
R279
100K
CR280
C286
.68PF
C285
.68PF
A5 70 MHZ TUNER
RAMP
C279
.001UF
C102
5000PF
E102
E103
CONT
C185
470PF
C284
470PF
C100
5000PF
SHIELD CAN
E100
E101
C283
470PF
<5>
H2
/LBAND
R205
8.25K
R216
8.25K
Q21
CR31
R215
20.0K
+11.8V
+11.8V
R214
4.75K
Q20
<3>
H3
C80
.1UF
R237
2.00K
VCO--- 70
+11.8V
<3>
H1
<6>
H5
VCO
+18V
C91
33UF
Q32
VCO
ON
+11.8V
R238
4.32K
+11.8V
<2>
A3
R240
5K
RF AGC
R239
5K
IF AGC
Q101
R305
1.62K
R307
2.00K
R306
17.8K
480--- IF
+11.8V
--- 18dBm
136 MHz
OUT
IF AGC
RF AGC
J11
I_AGC
R_AGC
REAR
PANEL
L BAND
INPUT
L BAND
IN
R236
4.75K
R234
24.3K
R235
3.01K
R233
2.00K
C89
.1UF
Q30
Q31
+11.8V
+11.8V
--- 11.8V
--- 11.8V
--- 11.8V
R217
2.74K
1705A SPECTRUM MONITOR
--- 30dBm
A6 2nd CONVERTER TUNER
RF INPUT <1>
RF INPUT <1>
RF INPUT <1>
RF INPUT <1>
PART OF A3 MAIN BOARD