User's Manual

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DIAGNOSTICS GUIDE
The BDA provides long term, care-free operation and requires no periodic
maintenance. There are no user-serviceable components inside the BDA.
This section covers possible problems that may be related to the installation or
operating environment.
Gain Reduction
Possible causes: Defective RF cables and RF connections to antennas, damaged
antenna or Leaky cable.
Excessive Intermodulation or Spurious
Possible causes: Amplifier oscillation caused by insufficient isolation. The isolation
between two antennae is given by the equation:
Isolation = 92.5 + 20 Log (F x D) – Gt – Gr
Where:
F = frequency (GHz)
D = separation (Km)
Gt = transmit antenna gain (in the direction of the receive antenna).
Gr = receive antenna gain (in the direction of the transmit antenna).
For the LTE 750 MHz frequencies, the antenna isolation at 100 m separation is
approximately 93.3 dB for Omni-directional antennas or leaky cable (0 dB gain). To
increase isolation, the antennas should have higher directivity and must be pointed
away from each other.
Occasional Drop-out of some Channels
Possible causes: One channel with very strong power dominates the RF output of the
amplifier.