Model8555A 
0 
0 
TUNING  STABILIZER  Switch:  Used 
to 
lock the 
lst 
LO 
to 
a  harmonic  of  a 
voltage~tuned 
crystal 
oscillator for scan  widths 
of 
100 
kHz  per division 
or 
less. 
Dial  Pointer:  Indicates center frequency 
to 
which 
analyzer 
is 
tuned by  FREQUENCY Control (2) in 
PER  DIVISION  and  ZERO  scan  modes. 
Also 
indicates 
LO 
center frequency  in  PER  DIVISION 
and  ZERO  scan  modes.  Indicates  marker  fre· 
quency  in  FULL  scan  mode.  Ganged 
to 
FRE-
QUENCY  Control; 
Fll'\IE 
TUNE  does 
not 
move 
dial pointer. 
BANDWIDTH  Control:  Selects  3 
dB 
IF 
bandwidths  to  determine  analyzer  resolution  in 
ZERO  and  PER  DIVISION  positions 
of 
SCAN 
WIDTH 
Mode  Switch  (10).  300  kHz  bandwidth 
automatically selected in  FULL scan  mode. 
EXT MIXER 
BIAS: Adjusts bias on external wave-
guide  mixer  diode;  adjusted  for  optimum  mixer 
sensitivity. 
SCAN 
WIDTH 
PER  DIVISION:  Indicates 
fre-
quency  scan  calibration;  scan  widths  from 
2 kHz/div 
to 
200  MHz/div  are  selectable. Scan 
is 
svmmetrical  about  center  frequency  selected  by 
FREQUENCY  (2)  and  FINE  TUNE  (3). Enabled 
by 
SCAN 
WIDTH 
mode switch (10). 
SCAN 
WIDTH 
Mode  Switch:  Selects ZERO, PER 
DIVISION  (9) 
or 
FULL  scan  modes. 
In 
ZERO 
scan  mode, analyzer acts 
as 
a fixed  tuned receiver 
at 
the  frequency  selected  by  FREQUENCY  (2) 
and  FINE 
TUNE  (3).  In  FULL  scan  mode,  the 
analyzer  scans  the  full  range  of  the  selected 
fre-
quency band. 
AMPL 
CAL:  Used  to  match 
RF 
Section with IF 
Section.  Sets overall 
gain 
of analyzer for absolute 
amplitude calibration. 
Frequency 
BANDS:  Set  of  fourteen,  indicates 
frequency  ranges 
of 
analyzer.  Green 
dot 
on  Fre-
quency  Scale  also  indicates  frequency  BAND 
selected. 
Frequency 
Scale:  Set 
of 
fourteen  scales, selected 
by frequency BAND lever. 
YIG-tuned 
Oscillator  (LO)  Fundamental  Fre-
quency  Scale:  Pointer  indicates  LO  center  fre-
quency. 
INPUT  ATTENUATION:  Attenuates 
input 
signal 
from 
0 
to 
50 
dB 
in  10 
dB 
steps. Maximum input 
signal  for  1 
dB 
signal  compression,  indicated on 
outer 
dial scale. 
~~:~~~~] 
DO 
NOT 
EXCEED THE FOLLOWING 
MAXIMUM 
INPUT 
LEVELS: 
Maximum 
POWER
1 
VOL 
TS
2 
Input 
Levels 
dBm 
Watts 
DC 
Rms 
Input 
0.01-18 
GHz 
+33 
2 
±20 
10 
Connector 
Incident 
on 
+10 
10mW 
±20 
0.707 
Input 
Mixer 
Operation 
Peak 
14.14 
1.0 
1 
The 
INPUT 
ATTENUATION 
control 
must 
be 
in 
the 
30 
dB 
or 
greater 
position 
when 
applying 
+33 
dBm 
or 
input 
mixer 
will 
be 
damaged. 
The 
power 
levels 
!sited 
apply 
for 
peak 
or 
average 
power. 
2
Do 
not 
exceed± 
20 
volts 
de. 
Apply 
only 
de 
voltages 
with 
rise 
times 
less 
than 
106 
volts 
per 
second. 
Do 
not 
change 
IN-
PUT 
ATTENUATION 
levels 
when 
de 
voltages 
are 
applied 
to 
RF 
INPUT 
Connector. 
DISPLAY  UNCAL:  Display  uncalibrated warning 
lights  when  relationship  between  scan  time,  scan 
width, bandwidth, and video  filtering 
is 
such 
that 
accuracy of vertical calibration 
is 
impaired. 
EXT  MIXER 
Input: 
External  mixer  input  for 
analyzer operation  over 
10.4 
to 
43 GHz frequency 
range. 
BNC 
female  connector; acc.epts  cable  from 
external  mixer. 
Supplies 
LO 
signal  to  external 
mixer and returns 
IF 
Signal  from mixer. Terminate 
in 
50  ohm load  when 
not 
in  use.  See  Figure  3-6, 
External Mixer 
Operation. 
'I'o 
prevent  damage  to external  mixer do 
not 
apply  more  than  1 
mW 
to  11517A 
mixer. 
F1RST  LO  OUTPUT:  2 
to 
4  GHz 
output 
from 
YIG-tuned  oscillator.  Female 
BNC 
connector, 
terminate in  50-ohm load when 
not 
in use. 
SECOND 
LO 
OUTPUT:  1.5 
GHz 
output 
from 
second 
LO.  Female 
BNC 
connector, terminate in 
50*ohm load when 
not 
in use. 
RF 
INPUT: 
Input 
for  .01  to  18  GHz  signals. 
Female 
type 
N  connector  (Option  001 
APC-7 
connector). 
See  0  above. 
*Indicates 
550 
MHz 
FIRST 
IF, 
Figure 
3-1. 
Front Panel Controls,  Connectors and Indicators 
(cont'd) 
3-5