Sherwood R-772 Service Manual page 9

AM SECTION
Measurements condition AM - MW : Radio frequency = 1000/999kHz, Audio frequency = 400Hz
Reference level = 74dBu/m), (50) ohms
Test Point : MW
Test Point : MW
NO.
1
TUNING COVER RANGE (A)
TUNING COVER RANGE
STEP (A)
STEP (RDS)
2
USABLE SENSITIVITY
S/N = 20dB
3
S/N RATIO (100)dBu/m, 30% MOD
4
T. H. D 74dBu/m, 30% MOD
5
OVER LOAD DISTORTION 100dBu/m, 80% MOD
6 FREQUENCY RESPONSE
(at 74dBu/m, 400Hz)-NO FILTER
SELECTIVITY AT SN : 20dB, ±10kHz(A)
7
SELECTIVITY AT SN : 20dB,
8 AGC FIGURE OF MERIT
9
IMAGE REJECTION
10
WHISTLE MODULATION (74dBu/m, 900Hz)
11
TUNED LEVEL 1000kHz(A), 999kHz(RDS)
12 AUTO STOP LEVEL 1000kHz(A), 999kHz(RDS)
13
OUTPUT LEVEL 74dBu/m, (30)% MOD
Modulation = 30%
TP1 = (600)kHz TP2 = (1000)kHz
TP1 = (594)kHz TP2 = (999)kHz
DESCRIPTION
(RDS)
±9kHz(RDS)
(at 100dBu/m)
8
TP3 = (1400)kHz
TP3 = (1404)kHz
UNIT
LOW ~ HIGH MW kHz
LOW ~ HIGH MW kHz
AUTO/Man. kHz
AUTO/Man. kHz
TP 1 dBu/m
TP 2 uV/m
TP 3 uV/m
TP 2 dB
TP 2 %
TP 2 %
AT-6dB Hz
TP 2 dB
TP 2 dB
TP 3 dB
2IF %
dBu/m
dBu/m
mV rms
(A)
(RDS)
LIMIT L/R NOMINAL L/R
520~1710
522~1611
10/10
9
63 65
63 63
63 63
35 30
2 3
3 5
80~2K 100~1.8K
23 20
50 40
28 25
10 15
55±10 55±15
55±10 55±15
200±100 200±150