Andrew MAAIS Installation manual

Channelized Amplifier Installation Instruction

1. INTRODUCTION

This document provides installation instructions for the Midway Airport Air Interface System
(MAAIS). This system shall be used as an air interface for the new Midway Airport Terminal
Development Program, Passive Radio Support System.

2. EQUIPMENT

2.1 Channelize Amplifier Racks

The engineers/technicians must read the RF Radiation Hazard section before they proceed any
installation work. Install both channelize amplifier racks in the MDF room of area 10–153. Each
equipment rack has been pre-assembled the internal cabling among all the modules and there are
four interconnect RF cables between these two racks and Figure 1, 2, 3 and 4 have indicated. The
interconnections are listed in the following:

a. The first cable is from the bottom of rack #1’s combiner (VHF Downlink Port) to

rack #2’s VHF D/L Combiner (Downlink Port).

b. The second cable is from the bottom of rack #1’s combiner (VHF Uplink Port) to

rack #2’s VHF U/L Splitter (Uplink Port).

c. The third cable is from the rack #1’s UHF Duplexer/CBC (Downlink Port) to rack

#2’s UHF D/L Combiner (Downlink Port).

d. The fourth cable is from rack #1’s UHF Duplexer/CBC (Uplink Port) to rack #2’s

UHF U/L Splitter (Uplink Port).

The bottom floor panel of raise floor beneath the rack will need to be removed for routing the six
(6) antenna feeder cables. The cable connecting ports are shown in Figure 1, 2, 3 and 4. The
cable connections between the antenna and equipment racks are listed in the following:

a. The UHF 1 antenna’s downlink cable will connect between the UHF 1 D/L outdoor

antenna and rack #1’s UHF D/L Splitter.

b. The UHF 1 antenna’s uplink cable will connect between the UHF 1 U/L outdoor

antenna and rack #1’s UHF U/L Combiner.

c. The UHF 2 antenna’s downlink cable will connect between the UHF 2 D/L outdoor

antenna and rack #2’s UHF D/L Splitter.

d. The UHF 2 antenna’s uplink cable will connect between the UHF 2 U/L outdoor

antenna and rack #2’s UHF U/L Combiner.

e. The VHF antenna’s downlink cable will connect between the VHF D/L outdoor

antenna and rack #2’s VHF D/L splitter.

f. The VHF antenna’s uplink cable will connect between the VHF U/L outdoor antenna

and rack #2’s VHF U/L Combiner.

The existing passive combiners currently in place shall be relocated into the channelize amplifier
equipment rack so all cable feeding these units shall also be relocated to the new equipment rack.

Note, there will not be access to the equipment rack from above so all cable will need to enter
the rack from below.

2.2 Transmission and Jumper Cable Installation

Install six (6) cable runs; one for each antenna to the MAAIS channelized amplifier equipment
racks. At the output of each antenna install a 3 ft. ½” jumper. From each jumper, install 7/8
“ Heliax cable from the antenna to the MDF room in area 10-153. The 7/8 “ Heliax shall not
exceed a bend radius of 10 inches. If the bend radius need to exceeded 10 inches, install a 3 ft.
of ½” jumper. The first transmission line interconnection, after entering the building shall be at
the Ground Bar Assembly housing the surge arrestors. At the junction install a 3 ft. of ½”
jumper between each run of 7/8” Heliax and surge arrestor. At the output of each surge arrestors
install a 3 ft. ½” jumpers. From the jumper route the transmission line from the over to the
channelized amplifier equipment racks. Reference Figure 3 and 4 for cable installation.

2.3 RF Radiation Hazard

RF radiation, (especially at UHF frequencies) arising from transmitter outputs connected to
AFL’s equipment, must be considered a safety hazard.

This condition might only occur in the event of cable disconnection, or because a ‘spare’
output has been left unterminated. Either of these conditions would impair the system’s
efficiency. No investigation should be carried out until all RF power sources have been
removed. This would always be a wise precaution, despite the se vere mismatch between the
impedance of an N type connector at 50?, and that of free space at 377?, which would
severely mitigate against the efficient radiation of RF power. Radio frequency burns could
also be a hazard, if any RF power carrying components were to be carelessly touched!

Antenna positions should be chosen to comply with requirements (both local & statutory)
regarding exposure of personnel to RF radiation. When connected to an antenna, the unit is
capable of producing RF field strengths, whic h may exceed guideline safe values especially
if used with antennas having appreciable gain. In this regard the use of directional antennas
with backscreens and a strict site rule that personnel must remain behind the screen while the
RF power is on, is strongly recommended. The minimum distance between the antennas and
nearby personnel requirement is 2meters.

“This equipment complies with part 90 of the fcc rules. Any changes or modifications not

expressly approved by the manufacturer could void the user’s authority to operate the

equipment.”

Where the equipment is used near power lines, or in association with temporary masts not
having lightning protection, the use of a safety earth connected to the case-earthing bolt is
strongly advised.