FM Receivers
91
FM 20 dB Quieting Sensitivity Measurement
Description
This procedure is used to measure an FM Receiver’s quieting
sensitivity (20 dB reduction in noise). A reference is established with
no signal at the Receiver’s antenna, then an un-modulated carrier is
applied and the RF amplitude is increased until a 20 dB reduction in
noise is measured at the audio output.
DUPLEXTXRX PREV TESTS
CONFIGHELPMSSG HOLD PRINT
SCREEN CONTROL
LOCAL
ADRS
REC AL L
SAV E
MEAS
RESET
PRESET
INSTRUMENT STATE
DATA FUNCTIONS
INCR
: 10
REF SET
IN CR
SET
METER
INCR X10
AVG
LO LIMIT HI LIMIT
CURSOR CONTROL
PUSH TO SELECT
CAN CEL
SHIFT
k1
k1’
k2
k2’
k3
k3’
k4
ASSIGN
k5
RELEASE
USER DATA
789
456
123
0
+
_
ENTER
GHz
dBm
dB
MHz
V
%
kHz
mV
s
Hz
µV
ms
%
dBµV
Ω
ppm
W
NO
ON/OFF
YES
MEMORY
CARD
AUDIO IN
LOHI
!
MAX
42 v Pk
!
MAX
12 v Pk
AUDIO OUTSQUELCHVOLUMEMIC/ACC
MA X POWER 200 mW
!
ANT INDUPLEX OUTRF IN/OUT
!
MA X POWER 60 W
CONTINUOUS
POWER
OFF ON
1
2
Data Entry
RX TEST
50Ω COXIAL
CABLE
TEST LOAD
RECEIVER UNDER TEST
ANTENNA (RF INPUT)
SPEAKER
(AUDIO
INPUT)
3
+
GND
Knob
Keys