Tektronix RFM150, Инструкция по эксплуатации

Страница: 127 / 278

Specifications
RFM 150 Instruction Manual 4–3
Table 4–2: Measurement accuracy (Cont.)
Name Description
Carrier Difference REQ:
±
1 dB Aural carrier-to-noise
≥
15 dB
(300 kHz bandwidth).
REF: Specification applies to visual-to-aural
carrier difference on any channel, where
the amplitude of the aural carrier is greater
than –20 dBmV.
Carrier-to-Noise REQ:
±
2 dB up to 47 dB (49 dB typical) for carrier
amplitude
≥
0 dBmV.
4, 5, 6
REF: C/N ratio is the ratio of the rms voltage of
the carrier, measured at the peak of the
modulation envelope, divided by the
average noise voltage in a 4.0 MHz
bandwidth.
Hum REQ:
±
1 % for visual carrier amplitude
≥
0 dBmV, visual
carrier-to-noise
≥
25 dB.
4
REF: Range: 1% to 5%.
REF: Hum is the peak-to-peak variation in visual
signal level caused by undesired low
frequency disturbances. It is expressed as
the percentage of the level of the peak-to-
peak interference compared to the peak
level of the RF signal.
4
Performance verified by measuring according to NCTA recommended practice.
5
For channel video bandwidths greater than 4 MHz, carrier-to-noise range is
decreased by 10 log (video bandwidth / 4 MHz).
6
For system B/G, with the lower adjacent channel carrying NICAM, C/N
measurement accuracy guaranteed for out-of-service measurements only.
Specifications
RFM 150 Instruction Manual 4–3
Table 4–2: Measurement accuracy (Cont.)
Name Description
Carrier Difference REQ:
±
1 dB Aural carrier-to-noise
≥
15 dB
(300 kHz bandwidth).
REF: Specification applies to visual-to-aural
carrier difference on any channel, where
the amplitude of the aural carrier is greater
than –20 dBmV.
Carrier-to-Noise REQ:
±
2 dB up to 47 dB (49 dB typical) for carrier
amplitude
≥
0 dBmV.
4, 5, 6
REF: C/N ratio is the ratio of the rms voltage of
the carrier, measured at the peak of the
modulation envelope, divided by the
average noise voltage in a 4.0 MHz
bandwidth.
Hum REQ:
±
1 % for visual carrier amplitude
≥
0 dBmV, visual
carrier-to-noise
≥
25 dB.
4
REF: Range: 1% to 5%.
REF: Hum is the peak-to-peak variation in visual
signal level caused by undesired low
frequency disturbances. It is expressed as
the percentage of the level of the peak-to-
peak interference compared to the peak
level of the RF signal.
4
Performance verified by measuring according to NCTA recommended practice.
5
For channel video bandwidths greater than 4 MHz, carrier-to-noise range is
decreased by 10 log (video bandwidth / 4 MHz).
6
For system B/G, with the lower adjacent channel carrying NICAM, C/N
measurement accuracy guaranteed for out-of-service measurements only.