Blonder tongue AMM-806, Reference Manual

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System Calculations
The Amplifier Cascade Factor Chart (on previous page) is used
to predict performance considering the contribution of various
numbers of amplifiers. It assumes that all amplifiers are
operated at the same level (input level for noise, output level
for distortion). This is generally the case in a Unity Gain Based
System.
Example: What is the trunk CTB after 13 trunk amplifiers?
Given: 1. Single trunk amplifier CTB specification is 87 dB
@ 32 dBmV flat (from Manufacturers specs.)
2. Trunk output is 25 dBmV, channel 2 Trunk
output is 32 dBmV, channel 60 (7 dB linear tilt)
Step 1 Re-rate performance of single amp
based on actual operating level.
Geometric tilt center = 28.5 dBmV
Add .5 dB correction factor =
29 dBmV average level
32 - 29 = 3 dB x 2 (for CTB) = 6 dB
87 dB + 6 dB = 93 dB CTB @
29 dBmV average level
Step 2 Find cascade factor for CTB for 13
amps, on the chart = 22.28 dB
Step 3 Subtract cascade factor from single amp operating
performance
93 dB - 22.28 = 70.72 dB
CTB = 70.72 dB after 13 amps
Amplifier Cascade Factor - Example