Tait T850 II Series User manual

M850-00 1
Copyright TEL 31/09/98
T850 Series II
Base Station Equipment
400-520MHz
Service Manual
Issue 200
October 1998
M850-00-200

2 M850-00
31/09/98 Copyright TEL
T800
T800
Head Office
New Zealand
Tait Electronics Ltd
558 Wairakei Road
P.O. Box 1645
Christchurch
New Zealand
Phone: [phone]
Fax: [phone]
Radio Systems Division
535 Wairakei Road
P.O. Box 1645
Christchurch
New Zealand
Phone: [phone]
Fax: [phone]
Australia
Tait Electronics (Aust) Pty Ltd
186 Granite Street
Geebung
Queensland 4034
P. O . B o x 6 7 9
Virginia
Queensland 4014
Australia
Phone: [phone]
Toll Free: 1800 077-112
Fax: [phone]
Beijing
Tait Mobile Radio (HK) Ltd
Beijing Representative Office
Room 812, Tower A
Beijing Bright China
Chang An Building
No. 7 Jianguomennei Dai Jei
Dongcheng District
Beijing
China 100005
Canada
Tait Mobile Radio Inc.
Unit 5, 158 Anderson Avenue
Markham
Ontario L6E1A9
Canada
Phone: [phone]
Toll Free: 1 800 890-8248
Fax: [phone]
France
Tait France Sarl
2 Avenue de la Cristallerie
92 316 Sèvres, Cedex
France
Phone: [phone]
Fax: [phone]
Germany
Tait Mobilfunk GmbH
Willstätterstraße 50
D-90449 Nürnberg 60
Germany
Phone: [phone]
Fax: [phone]
Hong Kong
Tait Mobile Radio (HK) Ltd
Unit 2216
North Tower
Concordia Plaza
No. 1, Science Museum Road
Tsim Sha Tsui East
Kowloon
Hong Kong
Phone: [phone]
Fax: [phone]
New Zealand
Tait Communications Ltd
Unit 4, 75 Blenheim Road
P. O . B o x 11 8 5
Christchurch
Phone: [phone]
Fax: [phone]
Singapore
Tait Electronics (Far East) Pte Ltd
4 Leng Kee Road
SIS Building #05-11A
Singapore 159088
Phone: [phone]
Fax: [phone]
Ta i w a n
Tait Mobile Radio (Taiwan) Ltd
1104, No. 142 Chung Hsiao E. Rd
Sec. 4
Taipei
Taiwan
Phone: [phone]
Fax: [phone]
Thailand
Tait Mobile Radio Ltd
14/1 Suwan Tower
Ground Floor
Soi Saladaeng 1
North Sathorn Road
Bangrak
Bangkok 10500
Thailand
Phone: [phone]
Fax: [phone]
United Kingdom
Tait Europe Ltd
Ermine Business Park
Ermine Road
Huntingdon
Cambridgeshire PE18 6YA
United Kingdom
Phone: [phone]
Fax: [phone]
USA
Tait Electronics (USA) Inc.
9434 Old Katy Road
Suite 110
Houston
Texas 77055
USA
Phone: [phone]
Toll Free: 1 800 222-1255
Fax: [phone]

M850-00 3
Copyright TEL 31/09/98
About This Manual
Scope This manual contains general, technical and servicing informa-
tion on T850 Series II 25W, 50W and 100W base stations which
comprise the following equipment:
Format We have published this manual in a ring binder so that "revision
packages" containing additional information pertaining to new
issues of PCBs can be added as required.
Revision Packages Revision packages will normally be published to coincide with
the release of information on a new PCB, and may also contain
additions or corrections pertaining to other parts of the manual.
You may order as many packages as you require from your local
Tait Dealer or Customer Service Organisation. Revision pack-
ages are supplied ready-punched for inclusion in your manual.
Revision Control Each page in this manual has a date of issue. This is to comply
with various Quality Standards, but will also serve to identify
which pages have been updated and when. Each page and its
publication date is listed in the "List of Effective Pages", and a
new list containing any new/revised pages and their publica-
tion dates will be sent with each revision package.
Any portion of text that has been changed is marked by a verti-
cal line (as shown at left) in the outer margin of the page. Where
the removal of an entire paragraph means there is no text left to
mark, an arrow (as shown at left) will appear in the outer mar-
gin. The number beside the arrow will indicate how many para-
graphs have been deleted.
The manual issue and revision status are indicated by the last
three digits of the manual product code. These digits start at 200
and will increment through 201, 202, 203, etc., as revision pack-
ages are published, e.g:
Thus, issue 203 indicates the third revision to issue 2 and means
that three packages should have been added to the manual. The
25W base station T855 receiver
T856 25W transmitter
50W base station T855 receiver
T857 exciter
T858 50W power amplifier
100W base station T855 receiver
T857 exciter
T859 100W power amplifier
2
2 0 3
issue status revision status

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issue digit will only change if there is a major product revision,
or if the number of revision packages to be included means that
the manual becomes difficult to use, at which point a new issue
manual will be published in a new ring binder.
PCB Information PCB information is provided for all current issue PCBs, as well
as all previous issue PCBs manufactured in production quanti-
ties, and is grouped according to PCB. Thus, you will find the
parts list, grid reference index (if necessary), PCB layouts and
circuit diagram(s) for each individual PCB grouped together.
Errors If you find an error in this manual, or have a suggestion on how
it might be improved, please do not hesitate to contact Customer
Support, Radio Systems Division, Tait Electronics Ltd, Christch-
urch, New Zealand (full contact details are on page 2).
Updating Equipment And Manuals
In the interests of improving performance, reliability or servicing, Tait Electronics Ltd
reserve the right to update their equipment and/or manuals without prior notice.
Copyright
All information contained in this manual is the property of Tait Electronics Ltd. All
rights are reserved. This manual may not, in whole or part, be copied, photocopied,
reproduced, translated stored or reduced to any electronic medium or machine readable
form without prior written permission from Tait Electronics Ltd.
Ordering Tait Service Manuals
You can order additional copies of this service manual from your nearest Tait Dealer or
Customer Service Organisation. When ordering, make sure you quote the correct Tait
product code ("M" number).
Publication Information
T850 Series II Service Manual
Issue 200 published October 1998 Product Code M850-00-200

M850-00 5
Copyright TEL 31/09/98
Table Of Contents
This manual is divided into nine parts as listed below, with each part being further sub-
divided into sections. There is a detailed table of contents at the start of each part and/
or section.
Part Title
A Introduction To Servicing
B T855 Receiver
C T856 Transmitter & T857 Exciter
D T858 & T859 Power Amplifiers
E T850 VCO PCB Information
F Installation
G System Configurations
H T800 Ancillary Equipment
I Using T850 Series II Equipment In A Series I Rack Frame

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List Of Effective Pages
The total number of pages in this Manual is 440, as listed below.
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Part F
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M850-00 AI
Copyright TEL 31/09/98
Part A Introduction To Servicing
This part of the manual is divided into the sections listed below. These sections provide
some general and advisory information on servicing procedures, and a brief history of
PGM800Win programming software.
Section Title Page
1
1.1
1.2
1.3
1.4
General
Additional Technical Information
Caution: CMOS Devices
Caution: Aerial Load
Caution: Beryllium Oxide & Power Transistors
1.1
1.1
1.1
1.2
1.2
2
2.1
2.2
2.3
2.3.1
2.3.2
2.4
Mechanical
Torx Recess Head Screws
Pozidriv & Philips Recess Head Screws
Disassembly/Reassembly
Receivers/Exciters/Transmitters
Power Amplifiers
Cover Screw Torques
2.1
2.1
2.2
2.3
2.3
2.3
2.3
3
3.1
3.1.1
3.1.2
3.2
3.3
Component Replacement
Leaded Components
Desoldering Iron Method
Component Cutting Method
Surface Mount Devices
Cased Mica Capacitors
3.1
3.1
3.1
3.1
3.2
3.2
4
4.1
4.2
Software History
PGM800Win V1.0
PGM800Win V2.00
4.1
4.1
4.1
Figure Title Page
1.1
1.2
2.1
2.2
Typical Product Code & Serial Number Labels
Typical Anti-static Bench Set-up
Torx Screw Identification
Pozidriv & Philips Screw & Screwdriver Identification
1.1
1.2
2.1
2.2

AII M850-00
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M850-00 General A1.1
Copyright TEL 31/09/98
1 General
1.1 Additional Technical Information
If you have any questions about this manual or the equipment it describes, please con-
tact your nearest Tait Dealer or Customer Service Organisation. If necessary, you can get
additional technical help from Customer Support, Radio Systems Division, Tait Elec-
tronics Ltd, Christchurch, New Zealand (full contact details are on page 2).
When requesting information, please quote either the manual product code (e.g.
M850-00-200), or the equipment product code and serial number which are printed on a
label on the back of the product (as shown in Figure 1.1).
Figure 1.1 Typical Product Code & Serial Number Labels
If you require information about a particular PCB, please quote the full PCB internal
part number (IPN) which is screen printed onto the top side of the board (refer to the
appropriate PCB Information section in this manual for more details).
1.2 Caution: CMOS Devices
This equipment contains CMOS Devices which are susceptible to damage from static
charges. Care when handling these devices is essential. For correct handling proce-
dures refer to the manufacturers' data books, e.g. Philips data books covering CMOS
devices, or Motorola CMOS data books, Section 5 'Handling', etc.
An anti-static bench kit (refer to Figure 1.2) is available from Tait Electronics Ltd under
the following product codes:
• KS0001 - 1 conductive rubber bench mat
- 1 earth lead to connect the mat to ground
• KS0004 - 1 wrist strap.
this area used for regional
Type Approval information
product code
serial number
T835-10-0000 Rev 1
900000
Tait Electronics Limited
Made in New Zealand
T838-10-0000
Rev 1
900000
Tait Electronics Limited
Made in New Zealand

A1.2 General M850-00
31/09/98 Copyright TEL
Figure 1.2 Typical Anti-static Bench Set-up
1.3 Caution: Aerial Load
The equipment has been designed to operate safely under a wide range of aerial loading
conditions. However, we strongly recommend that the transmitter should always be
operated with a suitable load to prevent damage to the transmitter output power stage.
1.4 Caution: Beryllium Oxide & Power Transistors
The RF power transistors in current use all contain some beryllium oxide. This sub-
stance, while perfectly harmless in its normal solid form, can become a severe health
hazard when it has been reduced to dust. For this reason the RF power transistors
should not be broken open, mutilated, filed, machined, or physically damaged in any
way that can produce dust particles.
to building earth
(not mains earth)
conductive
wrist strap conductive rubber
bench mat

M850-00 Mechanical A2.1
Copyright TEL 31/09/98
2 Mechanical
2.1 Torx Recess Head Screws
Torx recess head screws are becoming the standard screw head type in all T800 Series II
equipment, with Pozidriv and Philips recess head screws being used in fewer applica-
tions.
The Torx recess head has the advantage of improved screwdriver tip location, reducing
the chances of screw head damage caused by the driver tip rotating within the recess. In
addition, using a ball-tip Torx screwdriver allows you to drive a Torx head screw with
the driver on a slight angle, which can be useful in situations where access is restricted.
It is important that you use the correct Torx screwdriver tip:
M3 screws - T10
M4 screws - T20.
Figure 2.1 below shows a typical Torx recess head screw (actual hardware may differ
slightly from this illustration due to variations in manufacturing techniques).
Figure 2.1 Torx Screw Identification
"star" shaped recess with
six internal notches

A2.2 Mechanical M850-00
31/09/98 Copyright TEL
2.2 Pozidriv & Philips Recess Head Screws
Pozidriv and Philips recess head screws will continue to be used in T800 Series II equip-
ment in a few special applications. It is important that you use the correct type and size
screwdriver for each screw type to avoid damaging the screw head.
It is particularly important that you do not use Philips screwdrivers on Pozidriv screw
heads as the tapered driving flutes of the Philips screwdriver do not engage correctly
with the parallel-sided slots in the Pozidriv screw head. This can result in considerable
damage to the screw head if the screwdriver tip turns inside the recess.
Note:
If you find you need excessive downwards pressure to keep the screwdriver
tip in the Pozidriv screw head, you are probably using the wrong type and/
or size screwdriver.
Figure 2.2 below shows the main differences between typical Pozidriv and Philips screw
heads and screwdriver tips (actual hardware may differ slightly from these illustrations
due to variations in manufacturing techniques).
Figure 2.2 Pozidriv & Philips Screw & Screwdriver Identification
driving flutes with
parallel sides
driving flutes with
tapered sides
Pozidriv Philips
internal notches
"star" markings
between slots
no special markings
slots with parallel sides
slots with tapered sides
ridges between
driving flutes

M850-00 Mechanical A2.3
Copyright TEL 31/09/98
2.3 Disassembly/Reassembly
2.3.1 Receivers/Exciters/Transmitters
To carry out alignment or change option links, you need to remove only the top cover,
i.e. the one adjacent to the front panel handle and on the opposite side to the main
D-range connector (D-range 1/PL100).
You need to remove the bottom cover to:
• access transmitter RF power transistors and many SMD components
• change solder blob links
• fit test leads to circuit block access points.
2.3.2 Power Amplifiers
You should carry out the tuning and power output level setting procedures with the
cover on.
2.4 Cover Screw Torques
Receivers/Exciters/Transmitters .. 1.36Nm/12lb-in.
Power Amplifiers .. 0.9Nm/8lb-in.

A2.4 Mechanical M850-00
31/09/98 Copyright TEL