Handbook No. 60-166101HBKMIssue No. A Date 15/02/2006Page 1 of 33
Baltimore Radio Repeater System
Maintenance Handbook
1. INTRODUCTION
Scope and Purpose of this Document
This handbook is for use solely with the equipment identified by the AFL Part Number shown on the
front cover. It is not to be used with any other equipment unless specifically authorised by Aerial
Facilities Limited. This is a controlled release document and, as such, becomes a part of Aerial
Facilities’ Total Quality Management System. Alterations and modification may therefore only be
performed by Aerial Facilities Ltd.
AFL recommends that the installer of this equipment familiarise his/herself with the safety and
installation procedures contained within this document before installation commences.
The purpose of this handbook is to provide the user/maintainer with sufficient information to service
and repair the equipment to the level agreed. Maintenance and adjustments to any deeper level must
be performed by AFL, normally at the company’s repair facility in Chesham, England.
This handbook has been prepared in accordance with BS 4884, and AFL’s Quality procedures, which
maintain the company’s registration to BS EN ISO 9001:2000 and to the R&TTE Directive of the
European Parliament. Copies of the relevant certificates and the company Quality Manual can be
supplied on application to the Quality Manager.
This document fulfils the relevant requirements of Article 6 of the R&TTE Directive.
Limitation of Liability Notice
This manual is written for the use of technically competent operators/service persons. No liability is
accepted by AFL for use or misuse of this manual, the information contained therein, or the
consequences of any actions resulting from the use of the said information, including, but not limited
to, descriptive, procedural, typographical, arithmetical, or listing errors.
Furthermore, AFL does not warrant the absolute accuracy of the information contained within this
manual, or its completeness, fitness for purpose, or scope.
AFL has a policy of continuous product development and enhancement, and as such, reserves the
right to amend, alter, update and generally change the contents, appearance and pertinence of this
document without notice.
All AFL products carry a twelve month warranty from date of shipment. The warranty is expressly on a
return to base repair or exchange basis and the warranty cover does not extend to on-site repair or
complete unit exchange.
Maintenance Handbook (1)
Baltimore Radio Repeater System
Maintenance Handbook (1)
Baltimore Radio Repeater System
Handbook No. 60-166101HBKM Page 3 of 33
6.3EC Declaration of Conformity .................................................................................................32
6.4Amendment List Record Sheet ............................................................................................... 33
Maintenance Handbook (1)
Baltimore Radio Repeater System
Handbook No. 60-166101HBKM Page 4 of 33
2. SAFETY CONSIDERATIONS
2.1 Earthing of Equipment
Equipment supplied from the mains must be connected to grounded outlets and earthed
in conformity with appropriate local, national and international electricity supply and
safety regulations.
2.2 Electric Shock Hazard
The risk of electrical shocks due to faulty mains driven power supplies whilst
potentially ever present in any electrical equipment, would be minimised by adherence
to good installation practice and thorough testing at the following stages:
a) Original assembly.
b) Commissioning.
c) Regular intervals, thereafter.
All test equipment must be in good working order prior to its use. High current power supplies can be
dangerous because of the possibility of substantial arcing. Always switch off during disconnection and
reconnection.
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
removed. This would always be a wise precaution, despite the severe 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, which 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.
all
RF power sources have been
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.
Maintenance Handbook (1)
Baltimore Radio Repeater System
Handbook No. 60-166101HBKM Page 5 of 33
2.4 Chemical Hazard
Beryllium Oxide, also known as Beryllium Monoxide, or Thermalox™, is sometimes
used in devices within equipment produced by Aerial Facilities Ltd. Beryllium oxide
dust can be toxic if inhaled, leading to chronic respiratory problems. It is harmless if
ingested or by contact.
Products that contain beryllium are load terminations (dummy loads) and some power amplifiers.
These products can be identified by a yellow and black “skull and crossbones” danger symbol (shown
above). They are marked as hazardous in line with international regulations, but pose no threat under
normal circumstances. Only if a component containing beryllium oxide has suffered catastrophic
failure, or exploded, will there be any danger of the formation of dust. Any dust that has been created
will be contained within the equipment module as long as the module remains sealed. For this reason,
any module carrying the yellow and black danger sign should not be opened. If the equipment is
suspected of failure, or is at the end of its life-cycle, it must be returned to Aerial Facilities Ltd for
disposal.
To return such equipment, please contact the Quality Department, who will give you a Returned
Materials Authorisation (RMA) number. Please quote this number on the packing documents, and on
all correspondence relating to the shipment.
PolyTetraFluoroEthylene, (P.T.F.E.) and P.T.F.E. Composite Materials
Many modules/components in AFL equipment contain P.T.F.E. as part of the RF insulation barrier.
This material should never be heated to the point where smoke or fumes are evolved. Any person
feeling drowsy after coming into contact with P.T.F.E. especially dust or fumes should seek medical
attention.
2.5 Laser safety
General good working practices adapted from
EN60825-2: 2004/ EC 60825-2:2004
Do not stare with unprotected eyes or with any unapproved optical device at the fibre
ends or connector faces or point them at other people, Use only approved filtered or
attenuating viewing aids.
Any single or multiple fibre end or ends found not to be terminated (for example, matched, spliced)
shall be individually or collectively covered when not being worked on. They shall not be readily
visible and sharp ends shall not be exposed.
When using test cords, the optical power source shall be the last connected and the first
disconnected.
Use only approved methods for cleaning and preparing optical fibres and optical connectors, do not
allow any dirt/foreign material ingress on the optical connector bulkheads and always keep optical
connectors covered to avoid physical damage.
The optical fibre jumper cable maximum bend radius is 3 cm (1 ¼" ), any smaller radii may result in
optical cable breakage or excessive transmission losses.
Caution: Do not get the Fibre Optic units wet, they are
weather proof.
NOT
2.6 Emergency Contact Numbers
The AFL Quality Department can be contacted on:
Telephone +44 (0)1494 777000
Fax. +44 (0)1494 777002
e-mail
Maintenance Handbook (1)
Baltimore Radio Repeater System
Handbook No. 60-166101HBKM Page 6 of 33
mail to:qa@aerial.co.uk
3. EQUIPMENT OVERVIEW/SPECIFICATIONS
The Baltimore repeater system consists of several items of hardware:-
Master Site Preston UHF Air Interface Channelised Amplifier (60-166101, rack mounting)
Master Site OCC UHF Air Interface Channelised Amplifier (60-166201, rack mounting)
Preston Six-Way Fibre Optic Master Site (60-166301, rack mounting)
OCC Six-Way Fibre Optic Master Site (60-166401, rack mounting)
Remote Site High Power UHF Bi-Directional Amplifier (60-166501, wall mounting)
MOCE Site Air Interface Repeater (60-166801, wall mounting)
6 x 114Ah Battery Backups (80-333201, wall mounting)
There are two master sites, one at PRESTON and one at OCC, each has a 19” rack cabinet
containing the four off-air receiving shelves, which also contain the power supplies and the DC/DC
converters (12V) for the FO shelf.
The master site equipment receives off-air transmissions which it channelises, (15 channels) and
sends this downlink signal data to six fibre optic RX modules. Remotely sited cell enhancers receive
this FO data, demodulate and amplify it and feed it to local LCX antennas.
At the remote sites, the same leaky feeder antennas receive mobile signals, band selectively amplify
them and send this uplink data back by FO to the master site where it is demodulated, channelised
and broadcast on the same air interface antenna that received the downlink signal.
Existing in the current system are bi-directional amplifiers in the 800MHz bands. These signals are
catered for using specialist cross-band couplers so that the 800MHz signals bypass the 490MHz
system path with negligible loss.
20dB couplers fitted at various points in the system ‘tap-off’ a signal suitable for monitoring the RF
power in any path.
Each active device is alarm monitored and these alarms are available either as separate volt-free
relay contact pairs, in groups (e.g. all downlink power amplifiers), or as an alarm summary of the
whole system with locally visible indications (LEDs).
Six 114Ah battery backup systems ensure no loss of coverage should mains power fail. At the time of
writing this document no information was available on which items of the system were to be fitted to
the battery backups.
Maintenance Handbook (1)
Baltimore Radio Repeater System
The Master Site equipment is supplied in two, 43U standard size (19”) rack cabinets with eight
shelves containing all the electronics to fulfil the required coverage. There is an off-air channelised
amplifier which feeds seven fibre transmitters for remote RF distribution with a complementary uplink
path from the remote sites being received in the same shelf by seven FO receiver/modems. The
master site also has the ability to vary the RF attenuation to each path remotely, via a binary
switching arrangement with the actuating wiring being available on a ‘krone-block’ connector mounted
in the lower rack space.
The two master sites are very similar and so only the PRESTON site will be specified – the two parts
lists are identical.
Alarms are provided for all the active modules, individually and in summary form as volt-free normallyclosed relay contacts.
3.3 Master Site Technical Specifications
PARAMETERSPECIFICATION
Frequency range:
Bandwidth:1.0MHz
Number of FO RX outputs7
Number of FO RX inputs7
Number of RF channels:15
Downlink air interface gain:55dB
Uplink air interface gain:75dB
Manual Gain Adjustment:0-15dB (in 1dB steps)
Remote gain adjustment:0-15dB (in 1dB steps)
Rejection at opposing band:> 60dB
Downlink1dB Compression Point:> +42.5dBm
Downlink 3rd Order Intercept Point:> +56dBm
Uplink 1dB Compression Point:> +30.5dBm
Uplink 3rd Order Intercept Point:> +43dBm
Noise Figure:<6.0dB at any gain setting
Impedance:50 ohms
RF Connectors:N type, female
Power Supply:110V AC (nominal)
Power consumption:<8A ( @ 12V)
Temperature range:
operational:
storage:
494.3-495.3MHz (Downlink)
497.3-498.3MHz (Uplink)
-10qC to +60qC
-40qC to +70qC
Maintenance Handbook (1)
Baltimore Radio Repeater System
Handbook No. 60-166101HBKM Page 8 of 33
3.4 Master Site Mechanical Specifications
PARAMETERSPECIFICATION
Height: 43U Standard 19” Rack
Rack
Width: 19" (482.6mm)
Depth: 600mm (800 optional)
Shelf
sizes:
range:
RF Connectors:N type female
FO connectorsFC/APC
Environmental Protection:IP44
Shelf
finish:
Height: See parts lists
Width:19" (482.6mm)
Depth:
operational:-10°C to +60°C Temperature
storage:-40°C to +70°C
Weight:>100kg
Humidity:10 – 90% non-condensing
Case:Alocrom 1200
Heatsinks:Matt black
Handles:Silver anodised
Fascia:Painted to RAL 7035
<400mm(excluding heatsinks,
connectors, handles and feet)
Unit supplied with suitable supply
Supply Cable:
input leads, connector and specified
length of cable
Maintenance Handbook (1)
Baltimore Radio Repeater System
Handbook No. 60-166101HBKM Page 9 of 33
3.5 Air Interface System Diagram, Drg. No. 60-166181
Maintenance Handbook (1)
Baltimore Radio Repeater System
Handbook No. 60-166101HBKM Page 10 of 33
Loading...
+ 23 hidden pages
You need points to download manuals.
1 point = 1 manual.
You can buy points or you can get point for every manual you upload.