LMDA3726 Series 1.2 GHz Compact MDU Amplifiers
Installation Manual
NOTE TO CATV SYSTEM INSTALLER
This reminder is provided to call the CATV system installer’s attention to Article 820-40 of the NEC that provides guidelines for proper grounding and, in particular,
specifies that the cable ground shall be connected to the grounding system of the building, as close to the point of cable entry as practical.
INSTALLATION & SETUP GUIDELINES
1.
Gain and cable slope controls are reachable under the housing lid. Refer to layout scheme on the cover under the housing lid for controls adjustment.
2.
This product is shipped with default 0 dB positions for all variable attenuator and equalizer sub-boards.
3.
Band selection is made by factory production. Please check ordering information below and contact factory for upstream/downstream band selections other than
the factory default.
4.
Before applying power to the amplifier make sure that the forward input level to the amplifier is not too high or damage to the amplifier might occur.
5.
Please check that the forward variable equalizers and mid-stage variable pad are set to 0 dB as factory default values.
6.
Now apply power to the amplifier and measure the amplifier forward output level at the 20 dB output test point. If it is very low then adjust the value of the input
variable attenuator until the desired output level is reached at the highest operating frequency. Remember that the level measured at the test point is 20 dB lower
than the real signal level.
7.
Rotate the equalizer potentiometer in order to activate the equalization function to adjust the output level to be flat across the full bandwidth. The input signal level
will now be flat too. Under this condition there will be best CNR across the full bandwidth.
8.
Now rotate the equalizer potentiometer, in order to activate the onboard equalization function, into the forward mid-stage equalizer socket to get as close as
possible to the desired output signal slope. The desired output slope is determined by your system design. Consult your system planner or your system maps for
this information.
9.
If you are having trouble obtaining the expected output levels then check the input test point to verify that the levels are as expected at the input of the amplifier. The
forward set-up is complete.
10
For the reverse path, inject into the forward output test point test carriers with the system design input signal level plus 20 dB (because the test point has 20 dB
loss) at each end of the upstream band.
11.
Verify that the upstream reference test point (note: this is commonly called the “X point” and it is measured at your node, or optical receiver, or at the first
downstream amplifier - consult with your system designer) has the proper upstream output signal levels. If it does not, rotate the variable attenuator and equalizer to
the desired levels.
12.
Record the in/out operating levels in this station.
INSTALLATION PRECAUTIONS TABLE
Precautions
Requirement
Facilitate service and maintenance
Allow a minimum of 35 in. (90 cm) clearance in front of the equipment rack(s)
Avoid direct heating or air conditioning
If unavoidable, use deflector plates
AC power source outlets
Locate equipment near sufficient outlets to provide power for test equipment and power tools
Rack support
Make certain rack supports are sufficiently rigid to support rack(s)
Building leakage
Beware of dripping water onto equipment from leaky roofs, waveguide roof entries, and cold water pipe condensations
ORDERING INFORMATION
Power Socket Type
Frequency Range
LMDA3726
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x
-
xx
A = 100-240 VAC (N. America)
45 = 5-42 MHz / 54-1220 MHz
B = 100-240 VAC (Europe)
81 = 5-85 MHz / 102-1220 MHz
C = 40-90 VAC (HFC-powered)
22 = 5-204 MHz / 258-1220 MHz
2-2035 Fisher Dr, Peterborough, ON K9J 6X6 Canada
+1.705.742.1350
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1.800.465.7046
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lindsaybb.com
All information is subject to change without notice.
Rev. 10/22 (LBB0471)
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Page 3 of 3
© 2022 Lindsay Broadband - a division of Technetix group. All rights reserved. Printed in Canada. Non-Lindsay Broadband product
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