100
1. Cross Modulation for One Amplifier at Operating Level:
2. To Sum Identical Cross Modulation Ratios:
See charts & examples starting on pages 84.
3. To Sum Different Cross Modulation Ratios:
See examples starting on pages 84.
4. Cross Modulation vs Channel Loading:
XM = Cross Modulation Ratio, expressed
as a negative (-) number.
Rule: 1 dB change of the output of an amplifier
will change the cross modulation by 2 dB.
Rule: For every double the number of amplifiers
with identical cross modulation there
is a 6 dB degradation in the total
cross modulation.
FCC Requirement XM = 51 dB
System Calculations
N = Number of equal
contributors
NF = Noise Figure
-59.2 = Thermal Noise in
4 MHz Bandwidth
(dBmV)
Carrier/Cross Modulation (XM)
Summary of Contents for AMM-806
Page 86: ...79 TVCB PC Installation ...
Page 93: ...86 SMI Installation Torque Patterns 1 Start Here 2 3 4 5 6 1 Start Here 2 3 4 4 PORT 8 PORT ...
Page 125: ...118 Fiber Optics Fiber Loss vs Path Length Single Mode 1550 nm ...
Page 156: ...149 Cable TV Channel Format NTSC NTSC Composite Video Waveform ...
Page 157: ...150 US Frequency Spectrum ...
Page 158: ...151 FCC Aeronautical Band Frequencies Used for Communication and Navigation ...
Page 175: ...168 Common CATV Symbols ...
Page 176: ...169 Common CATV Symbols ...
Page 177: ...170 Digital L Band Distribution Symbols ...
Page 178: ...171 Digital L Band Distribution Symbols ...
Page 183: ...176 Typical Cable Attenuation Chart in dB 100 Feet 68 F 20 C ...
Page 187: ...180 Echo Rating Graph ...
Page 188: ...181 Signal to Interference Limits Non Coherent Carriers ...
Page 190: ...183 Heterodyne Modulator Analog ...
Page 191: ...184 Heterodyne Processor Analog ...
Page 213: ...206 Multiplexers ...
Page 285: ...Rev 8 0 ...