Atec Tektronix-DMA120-DMA121 - Manual (Page 5)

page 5
DMA 120
Series
Characteristics NOTE: All specifications apply across the
operating temperature range (–5 to +40°C)
unless otherwise stated. All values refer to
measurement after 25-minute warmup. All
power measurements referenced to 75
Ω
impedance.
RECEIVER
Frequency Range (channel center
frequency) –
DMA120: 54 to 860 MHz.
DMA121: 50 to 866 MHz.
Resolution Bandwidths (typical) –
DMA120: 135 kHz, 6 MHz.
DMA121: 135 kHz, 8 MHz.
Input Impedance – 75
Ω , nominal.
Maximum Input –
RF Power: 120 dBµV (60 dBmV).
AC Volts: 90 V peak.
Distortion-free Dynamic Range – >40 dB.
Sensitivity – <20 dBµV (–40 dBmV).
DISPLAY MODES
Spectrum –
Displayed Level (average power of 64QAM
signal at 6.875 Msymb/s):
Minimum: 40 dBµV (–20 dBmV).
Maximum: 100 dBµV (40 dBmV).
Attenuation Steps: 5 dB, typical.
Attenuation Range: 35 dB, typical.
Vertical Scale: 10 dB/div, 10 to
90 dBµV, –50 to 30 dBmV, –100
to –20 dBm.
Span Settings: 2 to 824 MHz (fixed to
135 kHz RBW).
Flatness: ±1 dB.
Constellation –
Sizes: 64QAM, 256QAM.
Evaluation: Full constellation, quadrant,
single point (box).
Adaptive Equalizer –
Number of Taps:
DMA120: 8 feed-forward; 8 feed-back.
DMA121: 8 feed-forward; 24 feed-back.
Scale: +10 to –40 dBc.
Mask: DVB.
MEASUREMENT MODES
Signal Level –
Channel Bandwidth:
DMA120: 6 MHz.
DMA121: 8 MHz.
Level (channel average power):
Minimum: 40 dBµV/–20 dBmV.
Maximum: 100 dBµV/40 dBmV.
Accuracy:
64QAM: ±1.5 dB, referenced to 25°C.
256QAM: ±1.8 dB, referenced to 25°C.
Reference Units
(selectable): dBµV, dBmV, dBm, dBpW.
Pass/Fail Indication: User-adjustable
threshold.
In-service Measurement.
Channel Power-to-Noise –
Channel Bandwidth:
DMA120: 6 MHz.
DMA121: 8 MHz.
Maximum Ratio: 40 dB.
Accuracy: ±2.1 dB.
Pass/Fail Indication: User-adjustable
threshold.
In-service Measurement: Noise measure-
ment frequency out of channel.
Adjacent Channel Level –
Difference Amplitude Range:
DMA120: +10 to –25 dB.
DMA121: +15 to –25 dB.
Accuracy: ±2.1 dB referenced to 25°C.
Display Vertical Scale: 40 to 100 dBµV,
–20 to 40 dBmV, –65 to –5 dBm, 25 to
85 dBpW.
Pass/Fail Indication: User-adjustable
threshold.
In-service Measurement.
Modulation Error Ratio (MER) –
Range:
64QAM: 22 to 35 dB.
256QAM, DMA120: 28 to 35 dB.
256QAM, DMA121: 30 to 35 dB.
Accuracy: ±1.5 dB at 65 dBµV/5 dBmV,
referenced to 25°C.
Pass/Fail Indication: User-adjustable
threshold.
In-service Measurement.
Error Vector Magnitude (EVM) –
Range:
64QAM: 1.2 to 4.1%.
256QAM: 1.1 to 1.9%.
Accuracy: ±0.4% over 1.2 to 2.0% range;
±0.8% over 2.1 to 4.1% range at
65 dBµV/5 dBmV.
In-service Measurement.
Average Bit Error Rate (BER), Before R-S
Decoding –
Range:
64QAM: 10 –4 to 10 –9 .
256QAM, DMA120: 10 –4 to 10 –8 .
256QAM, DMA121: 10 –4 to 10 –6 .
User-selectable Time Period: 1 to 60
minutes.
Number of Periods Comparable: 24.
In-service Measurement.
Estimated Average Bit Error Rate (BER),
After R-S decoding –
User-selectable Time Period: 1 to 60
minutes.
Number Periods Comparable: 24.
In-service Measurement.
System Availability Statistics –
User-selectable Time Period: 1 to 60
minutes.
Errored Seconds.
Severely Errored Seconds:
Pass/Fail indication: User-settable
threshold.
Unavailable Time.
Severely Disturbed Period.
In-service Measurement.
Estimated Noise Margin –
Range:
DMA120: 64QAM – 1 to 12 dB,
256QAM – 2 to 7 dB.
DMA121: 64QAM – 1 to 10 dB,
256QAM – 3 to 5 dB.
Accuracy: ±1.5 dB at 65 dBµV/5 dBmV.
Symbol Rate –
Range:
DMA120: 5.057 to 5.360 Msymb/s.
DMA121: 5.000 to 6.956 Msymb/s.