TB 9-6625-152-24
14. Frequency Modulation
a. Performance Check
(1) Set TI as listed in (a) through (g) below:
(a) Press Rx TEST key then [RF Gen].
(b) Press FREQ and set to 0.5 MHz.
(c) Press LEVEL and set to 0 dBm.
(d) Press Rx TEST, [Mod Gen], [Gen1/Gen2] until MOD1 FREQ is
highlighted, then press ON OFF key to off.
(e) Press Rx TEST, [Mod Gen], [Gen1/Gen2] until MOD2 FREQ is
highlighted, then press ON OFF key until display extinguishes.
(f) Press Rx TEST, [Mod Gen], [Gen1/Gen2] until MOD2 FREQ is
highlighted, FREQ, and set to 1 kHz.
(g) Press Rx TEST, [Mod Gen], [Gen1/Gen2] until MOD2 FREQ is
highlighted, LEVEL and set to 10 kHz.
(2) Configure measuring receiver for FM deviation measurement with Peak+
detector, 50 Hz high pass filter and 15 kHz low pass filter. If measuring receiver indication
is not within limits specified in first row of table 10, perform b below.
(3) Repeat technique of (1) (a), (b), (g) and (2) above for remaining TI frequencies
and modulation levels in table 10. If measuring receiver indications are not within limits
specified in table 10, perform b below.
Table 10. Frequency Modulation @ 1 kHz.
Test instrument
Measuring receiver
Indication limit (kHz)1
Modulation level
(MHz)
(kHz)
Min
Max
0.5
10
9.290 (9.300)
10.710 (10.700)
10
10
9.290 (9.300)
10.710 (10.700)
10
20
18.590 (18.600)
21.410 (21.400)
10
50
46.490 (46.500)
53.510 (53.500)
10
70
65.090 (65.100)
74.910 (74.900)
100
10
9.290 (9.300)
10.710 (10.700)
500
10
9.290 (9.300)
10.710 (10.700)
750
10
9.290 (9.300)
10.710 (10.700)
1000
10
9.290 (9.300)
10.710 (10.700)
Values in parentheses are for model 2947A.
1
NOTE
For model 2947A continue with (4) below.
For model 2947
proceed to (10) below.
(4) Set TI as listed in (a) through (d) below:
(a) Press Rx TEST key then [RF Gen].
(b) Press FREQ and set to 0.5 MHz.
