Nautel CL40 Owner's manual
CL40
Antenna
Technical Instruction Manual
Issue 3.0 .................... 18 October 2011
Nautel Limited
10089 Peggy's Cove Road,
Hackett's Cove, NS, Canada B3Z 3J4
T. 877 6 nautel (628835) or +1.902.823.2233
F.+1.902.823.3183
U.S. customers please contact:
Nautel Inc.
201 Target Industrial Circle, Bangor ME 04401
T. 877 6 nautel (628835) or +1.207.947.8200
F.+1.207.947.3693
www.nautel.com
©Copyright 2011 NAUTEL. All rights reserved.
CL40 Antenna Technical Instruction Manual Oct.18.11
Warranty
by Nautel Limited/Nautel Inc. (herein after referred to as Nautel)
Nautel Limited/Nautel Incorporated, hereinafter referred to as Nautel, guarantees all mechanical and electrical parts of
the equipment for a period of thirteen months from date of shipment.
1. A "Part Failure" shall be deemed to have occurred when the part has become defective, or does not have the
characteristics required for the specified equipment performance:
(a) When the equipment is operated within the design parameters, and
(b) When the equipment is installed and adjusted according to Nautel's prescribed procedures as stated in
the instruction manual.
2. Nautel shall provide replacements for all "Parts" at no cost to the Customer when they become defective during
the warranty period, and upon the return of the defective part.
3. In the event that a "Part" fails during the warranty period and causes damage to a sub-assembly that cannot be
readily repaired in the field, the entire sub-assembly so damaged may be returned to Nautel for repair. The
repairs will be made without charge to the Customer.
4. Where warranty replacements or repair are provided under items 2 or 3, Nautel will pay that part of the shipping
costs incurred in returning the part/assembly to the Customer.
5. Warranty replacement parts and repair, which are provided under items 2 or 3, shall be guaranteed for a period
of ninety days from date of shipment or until the end of the original warranty period, whichever occurs later.
6. Nautel will not assume responsibility for any charges incurred by other than Nautel employees.
7. Nautel shall have the privilege of investigating whether failures have been caused by factors beyond its control.
8. Nautel shall in no event be liable for any consequential damages arising from the use of this equipment.
9. When requesting a warranty repair/replacement, please provide complete and accurate information. Observe
the instructions regarding 'Equipment Being Returned to Nautel' on page two of this warranty and provide the
information requested.
10. When ordering spare/replacement parts, please provide complete and accurate information. Refer to the parts
list of the Repair manual for ordering information. Provide as much of the information requested for 'Equipment
Being Returned to Nautel' on page two of this warranty as is practical. The information identified by an asterisk
is the minimum required.
Nautel Limited Nautel Inc.
10089 Peggy's Cove Road 201 Target Industrial Circle
Hackett's Cove NS Canada B3Z 3J4 Bangor ME USA 04401
T. 877 6 nautel (628835) or 1.902.823.2233 T. 877 6 nautel (628835) or 1.207.947.8200
F. 1.902.823.3183 F. 1.207.947.3693
24 hr. Answering Service 1.902.823.3900
Customer Service Notice
A ‘Technical Assistance’ and ‘Plug-in Module Exchange’ service is available to Nautel users.
CL40 Antenna Technical Instruction Manual Oct.18.11
Factory Support
TECHNICAL ASSISTANCE
Nautel's field service department provides telephone technical assistance on a 24 hour, seven days a week basis.
Requests by other media (facsimile or e-mail) will be responded to the next working day if received after Nautel's normal
working hours. Contact the appropriate field service centre from the following:
U.S.A. customers use: Nautel Incorporated T. +1.207.947.8200 (24 hours) or 877 6 nautel (628835)
201 Target Industrial Circle F. +1.207.947.3693
Bangor, Maine 04401
All other customers use: Nautel Limited T. +1.902.823.3900 (24 hours) or 877 6 nautel (628835)
10089 Peggy’s Cove Road, F. +1.902.823.3183
Hackett’s Cove, NS, Canada E-Mail support@nautel.com
B3Z 3J4 Web www.nautel.com
MODULE EXCHANGE SERVICE
In order to provide Nautel customers with a fast and efficient service in the event of a problem, Nautel operates a
factory rebuilt, module exchange service which takes full advantage of the high degree of module redundancy in
Nautel equipment. This module exchange service is operated from Nautel’s factory in Bangor, Maine and Hackett’s
Cove, Nova Scotia. These two locations allow us to provide a quick turn around service to keep our customers on
the air. During the transmitter’s warranty period, up to thirteen months from shipment, repair and exchange of
modules is at no charge to the customer. When the warranty has expired, a charge of 80% of the list price for all
exchanged modules is made. If the faulty module is returned to Nautel within 30 days, a credit is issued reducing
this charge by one half to 40% of the list price. U.S.A. customers are required to contact our Bangor, Maine facility.
Canadian and overseas customers should contact our Nova Scotia, Canada facility.
EQUIPMENT BEING RETURNED TO NAUTEL
For all equipment being returned to Nautel and all requests for repairs or replacements:
•Obtain an RMA number from Nautel (you must have an RMA number to return equipment)
•Mark the item as 'field return'
•Mark the item with the RMA number assigned by Nautel
•Address the item to the appropriate Nautel facility
Complete and accurate information regarding the equipment being returned will ensure prompt attention and will
expedite the dispatch of replacements. Refer to the nameplate on the transmitter and/or the appropriate
module/assembly to obtain name, type, part and serial number information. Refer to the parts list of this manual or the
appropriate service instruction manual for additional ordering information.
The following information should accompany each request:
* Model of Equipment
* Serial number of Equipment
* Name of Part/Assembly
Serial number of Part/Assembly
* Complete reference designation of Part/Assembly
* Nautel's part number of Part/Assembly
* OEM's part number of Part/Assembly
Number of hours in Use
Nature of defect
* Return shipping address
* Denotes minimum information required to order spare/replacement parts
CL40 Antenna Technical Instruction Manual Oct.18.11
Safety Symbols
General definitions of safety symbols used on equipment or in manuals.
DANGER – HIGH VOLTAGE
Indicates dangerous voltages (in excess of 72 V), capable of causing a fatal
electrical shock, are present on or near parts bearing this label.
GROUND (EARTH)
Used with wiring terminals to indicate the terminal must be connected to
earth ground before operating equipment. If power is supplied without
grounding the equipment, there is a risk of receiving a severe or fatal
electrical shock. Also used on electrical schematics to indicate a part that is
connected to earth ground.
GROUND (PROTECTIVE or SAFETY)
Used with protective (safety) conductor terminals to indicate the terminal
must be connected to ground before operating the equipment. If power is
supplied without grounding the equipment, there is a risk of receiving a
severe or fatal electrical shock.
ELECTROSTATIC SENSITIVE
Indicates a part or assembly is or contains devices that are electrostatic
sensitive. To prevent damage to these devices, ensure the handling
procedures outlined in this manual are observed.
WARNING A WARNING denotes a hazard. It identifies an operating procedure,
condition, etc. which, if not strictly observed or adhered to, could result in
injury or death to personnel. Throughout the technical manual, a
WARNING shall immediately precede the text to which it applies.
CAUTION A CAUTION denotes a hazard. It identifies an operating procedure,
condition, etc., which, if not strictly observed or adhered to, could result in
damage to, or destruction of the equipment. Throughout the technical
manual, a CAUTION shall immediately precede the text to which it
applies.
NOTE A NOTE denotes important information pertaining to an operating
procedure, condition, statement, etc., which is essential to highlight. A
NOTE may precede or follow the text to which it applies.
CL40 Antenna Technical Instruction Manual Oct.18.11
Safety
Toxic Hazard Warning
There are devices used in this equipment containing beryllium oxide ceramic,
which is non-hazardous during normal device operation and under normal device
failure conditions. These devices are specifically identified in the equipment parts
list(s) by including ‘BeO’ in the part’s description.
DO NOT cut, crush or grind devices because the resulting dust may be
HAZARDOUS IF INHALED. Unserviceable devices should be disposed of as
harmful waste.
CL40 Antenna Technical Instruction Manual Oct.18.11
Contents Page
1 GENERAL INFORMATION
1.1 INTRODUCTION 1-1
1.2 FACTORY SUPPORT 1-1
1.3 PURPOSE AND SCOPE OF MANUAL 1-1
1.4 PURPOSE OF EQUIPMENT 1-1
1.5 MECHANICAL DESCRIPTION 1-1
1.6 TOOLS 1-1
1.7 TECHNICAL SPECIFICATIONS 1-2
2 PREPARATION FOR USE AND INSTALLATION
2.1 INTRODUCTION 2-1
2.2 SITE SELECTION 2-1
2.3 BASE INSTALLATION 2-1
2.3.1 Standard Concrete Base 2-1
2.3.2 Non-Standard Base 2-1
2.4 ANTENNA ASSEMBLY AND ERECTION 2-1
2.5 ADJUSTING THE SPARK GAP 2-6
2.6 ANTENNA MAINTENANCE 2-6
3 PARTS LIST
3.1 INTRODUCTION 3-1
3.1.1 Item Number 3-1
3.1.2 Nautel Number 3-1
3.1.3 Description 3-1
3.1.4 Quantity 3-1
4 TUNING
4.1 INTRODUCTION 4-1
4.2 ANTENNA GROUND 4-1
CL40 Antenna Technical Instruction Manual Oct.18.11
Contents Page
List of Tables
1-1 Tools Required 1-2
2-1 Loading Coil Configuration versus Frequency (standard antennas) 2-4
2-2 Antenna Reactance vs Frequency 2-6
2-3 Loading Coil Configuration versus Frequency (Top Loading Kit only) 2-26
3-1 Mechanical Parts List, CL40 Antenna (Nautel # 199-9000-04) 3-2
3-2 Hardware Kit, CL40 Antenna (Nautel # 199-9064-03) 3-3
3-3 Ancillary Kit, CL40 Antenna (Nautel # 199-9072) 3-3
3-4 Top Loading Kit, CL40 Antenna (Nautel # 199-9085) 3-4
3-5 Guy Wire Kit, CL40 Antenna (Nautel # 199-9087) 3-4
List of Figures
2-1 CL40 Antenna (Lowered Position) 2-7
2-2 CL40 Antenna (Fully Assembled, Raised Position) 2-8
2-3a Standard Concrete Base 2-9
2-3b Non-Standard Base 2-10
2-4 Winch Mounting 2-11
2-5 Bottom Clamp Mount 2-12
2-6 Lower Mast Splice Joining 2-13
2-7 Lift Bracket/Lightning Bypass Bracket/Weather Protector 2-14
2-8 Upper Mast Splice 2-15
2-9 Upper Mast into Insulator 2-16
2-10 Radials/Ring/Plate 2-17
2-11 Vertical Radiator/Connector Cable 2-18
2-12 Wooden ‘A’ Frame 2-19
2-13 Mounting Loading Coil Enclosure A1 2-20
2-14a Loading Coil Configuration, Series Connected 2-21
2-14b Loading Coil Configuration, Parallel Connected 2-22
2-15a Ground Mat Installation, 6 Radials 2-23
2-15b Ground Mat Installation, 60 Radials 2-24
2-16 ATU Mounting 2-25
2-17a Top Loading Kit – Site and Foundation Preparation 2-27
2-17b Guy Wire Kit – Site and Foundation Preparation 2-29
2-18 Top Loading Kit – Installation Details 2-31
2-19 Guy Wire Kit – Installation Details 2-33
2-20 Installing Solar Light Mounting Assembly 2-35
CL40 Antenna Technical Instruction Manual Oct.18.11
Release Control Record
Issue Date Reason
3.0 18 October 2011 CL40 Part # 199-9000-04: structural strength
improvements
CL40 Antenna Technical Instruction Manual Page 1-1
Section 1 General Information Issue 3.0
CL40 ANTENNA
TECHNICAL INSTRUCTIONS
Section 1 GENERAL INFORMATION
1.1 INTRODUCTION
This antenna is intended primarily for use
with low and medium powered transmitter/
antenna tuning unit systems in the LF and
MF bands. It is particularly intended for use
with aeronautical and marine radio
beacons (NDBs).
1.2 FACTORY SUPPORT
Nautel provides after sales factory
support. Technical assistance is available
on a 24 hour, seven days a week basis. A
factory service facility for repair of
modules/assemblies is also available.
Refer to the Factory Support portion of the
Warranty pages at the front of this manual
for additional information.
1.3 PURPOSE AND SCOPE OF
MANUAL
This Technical Instruction manual
provides the information required to
install, operate and maintain the
equipment.
1.4 PURPOSE OF EQUIPMENT
When combined with an appropriate
transmitter system, the CL40 antenna
provides reliable facilities for an NDB
reference station.
1.5 MECHANICAL DESCRIPTION
The antenna consists of a free-standing
tubular mast, topped by a hexagon-shaped
capacitive loading structure (or top hat)
which provides the necessary load for RF
current flow. The top hat and the upper half
of the mast are isolated from the lower
mast by a high voltage insulator. Both mast
and top hat are constructed from
lightweight aluminum alloy for easier
transportation and erection and reduced
maintenance requirements. The lower
antenna mast is secured with two clamps
to an aluminum alloy pipe (anchor post)
section which is normally embedded in
concrete. A winch is secured to the anchor
post and connects to the lower antenna
mast with its 3/16” stainless steel wire rope.
Mounted below the mast insulator is the
loading coil enclosure with its upper end
connected to the top hat via the upper mast
section and its lower end connected to a
solid copper wire downlead. A cowl
protects the insulator from direct
precipitation. The downlead is supported
approximately twelve inches distant from
the tower by insulating spacers and carries
the RF current to the antenna loading coils
from the antenna tuning unit (ATU) which is
located on the anchor post at a convenient
height near ground level.
A ground plane of copper radials provides
the RF current return path and completes
the system.
1.6 TOOLS
Table 1-1 lists the tools that are required
to install and maintain the CL40 Antenna.
Page 1-2 CL40 Antenna Technical Instruction Manual
Issue 3.0 Section 1 General information
Table 1-1: Tools Required
TOOL TYPE
Socket Set Metric 8 mm to 19 mm, SAE 5/16 in. to 3/4 in.
Combination Wrench Set Metric 8 mm to 19 mm, SAE 5/16 in. to 3/4 in.
Adjustable Wrench Opens to 1-1/4 in.
Screwdrivers Slot Head (medium), Philips
Level 4 ft.
Propane Torch Suitable for soldering
Solder and flux Suitable for application
Hammer Standard
Pliers 10 in. vise grip
Electricians side cutting
Wood for A-Frame Support (Fig.2-12) 8 ft. length of 2 x 4 (qty 2)
4 ft. length of 2 x 4 (qty 1)
Tension Meter (required when top
loading kit or guy wire kit is purchased) Capable of at least 1600 lb measurement
1.7 TECHNICAL SPECIFICATIONS
ELECTRICAL
Frequency Range ..............................................................190 to 1250 kHz and 1600 to 1800 kHz
Input RF Power Rating ..........................................................................up to 250 W, 1000 W peak
Top Section Capacity (standard antennas) ...........................................................225 pF (approx.)
Top Section Capacity (with top loading antenna kit option)..................................370 pF (approx.)
Loading Coil Quality Factor.........................................................................................................600
Radiation Pattern ....................................................................................................Omni-directional
MECHANICAL
Installed Height .......................................................................................................................40 feet
Ground Plane...........................................Configurations are available to suit specific installations
Mast and Radiator Material ...............................................................High strength aluminum alloy
Environmental Limits ................................................................................................-50°C to +55°C
Maximum Wind Velocity ........................................................................100 miles per hour (no ice)
(110 miles per hour with Guy Wire Kit)
Maximum Ice Loading................................................................................ 3/4-inch radial thickness
NOTE
Failure to follow recommendations and instructions in this manual may void the
manufacturer’s warranty. Please review Nautel’s warranty for more information.
CL40 Antenna Technical Instruction Manual Page 2-1
Section 2 Preparation for Use and Installation Issue 3.0
CL40 ANTENNA
TECHNICAL INSTRUCTIONS
Section 2 PREPARATION FOR USE AND INSTALLATION
2.1 INTRODUCTION
This section contains installation information
for the antenna. Nautel recommends that all
requirements be incorporated to ensure
optimum reliability and performance.
2.2 SITE SELECTION
The antenna’s intended application dictates
its general location. Consider the following
factors when selecting a site:
•The area near the antenna should be
free from other fixed structures (e.g,
overhead power lines, other antennas).
•The material already in place should be
of sufficient depth and competence to
support the antenna base (see 2.3 for
base installation options).
•Consider the potential difficulties that
may be encountered when burying the
ground mat.
2.3 BASE INSTALLATION
Once the specific site has been selected,
excavate for, as necessary, and install the
base as detailed in Figure 2-3a (standard
concrete base, see also 2.3.1) or 2-3b
(non-standard base, see also 2.3.2).
NOTE
Various factors can affect the installation of
the selected antenna base. Refer to the
General Notes in Figure 2-3a if using a
standard concrete base.
Top Loading Kit: If you purchased the Top
Loading Kit (Nautel # 199-9085), see Figures
2-17 and 2-18 to prepare your location and
install the foundation and guy wires. Use
Table 2-3, not Table 2-1, to configure the
loading coils.
Guy Wire Kit: If you purchased the Guy
Wire Kit (Nautel # 199-9087), see Figures
2-17 and 2-19 to prepare your location and
install the foundation and guy wires.
Consult a local Civil Engineer prior to
installing the antenna base to ensure proper
installation and – in the case of the non-
standard base – mounting hardware
selection and anchoring foundation design.
For all types of base mounting design
assuming a net overturning moment at the
top of the base of 18,500 ft-lbs.
2.3.1 Standard Concrete Base
For the standard concrete base (see
Figure 2-3a), the anchor post (item 26) is
cast in the concrete base. A 17/32”
diameter drain hole, 52” from the bottom
of the post can be used to determine the
depth to embed the anchor post in the
concrete. Embed the post in the concrete
such that this drain hole is approximately
4” above the concrete. Keep the drain
hole clear. Ensure that the anchor post is
maintained perfectly plumb until the
concrete has set. Orient the 17/32“
diameter holes at the top of anchor post
at right angles to the intended axis of the
laid down antenna.
2.3.2 Non-Standard Base
For the non-standard base (see Figure
2-3b), the anchor post is part of a welded
base that includes a base plate and
support gussets. A 9/16 in. diameter drain
hole is located above the base plate.
2.4 ANTENNA ASSEMBLY AND
ERECTION
Use Figures 2-1 and 2-2, which depict the
complete assembly of the antenna, in
conjunction with the following instructions.
Page 2-2 CL40 Antenna Technical Instruction Manual
Issue 3.0 Section 2 Preparation for Use and Installation
(a) Unpack the antenna components. Use the
parts lists in Section 3 to verify all
components have been received.
(b) Install the winch assembly (item 19) on
top of the anchor post using the hardware
provided. See Figure 2-4.
(c) Mount the bottom clamp assembly (item
20) less the outer saddle to the anchor
post approximately eight inches up from
the top of the concrete. See Figure 2-5.
(d) Remove the 1/2” x 9-1/2” stainless bolt
from the bottom clamp assy (item 20) and
install the lower mast section (item 30)
with the notch pointing up. Install the 1/2”
locknut until a few threads protrude past
the end of the nut. Install the two lower
mast splices (item 17) to the lower mast
section using two 5/8 x 6 galvanized bolts
with 10 (5 per) galvanized flat washers, 2
galvanized split washers and 2
galvanized nuts (items 57, 65, 63 & 64).
See Figure 2-6. Leave the bolts loose.
Insert the lower mast section, upper half
(item 31) into the splice and bolt in place
with two 5/8x6 galvanized bolts with 10
(5 per) galvanized flat washers,
2 galvanized split washers and 2
galvanized nuts (items 57, 65, 63 & 64).
Tighten the joint.
(e) Install the mast insulator assembly (item
11) by inserting the end with the spark ball
completely into the upper end of the lower
mast section (item 31). Rotate the
insulator assembly until the lightning spark
ball faces the ground. Attach the Lifting
Bracket (item 15) and the Lightning
Bypass Bracket (item 28) using two 5/8" x
6" galvanized bolts complete with 8
galvanized flat washers (2 per side), 2
galvanized split washers and 2 galvanized
nuts (items 57, 65, 63 & 64) to the lower
mast section. See Figure 2-7.
NOTE
Mount the lifting bracket on the same side as
the notch on the bottom of the lower mast
section so that it points up.
(f) Attach the winch cable to the lifting
bracket and, using the winch, raise the
lower mast section so that the end is
about 3 ft (1 m) from the ground.
(g) Attach the upper down lead insulator
assembly (item 18) to the lower mast
section approximately 5 ft below the
bottom hole in the lifting bracket.
Position the insulator so that it points at
the ground and on the same side of the
lower mast as the winch handle. Repeat
with the lower downlead insulator assy,
however position it about 7 ft from the
bottom of the lower mast section.
(h) Connect the two sections of the upper
mast (items 32 & 33) together using two
upper mast splices (item 12) and four
5/8"x 4-1/2" galvanized bolts with 8
galvanized flat washers, 4 galvanized
split washers and 4 galvanized
nuts.(items 60, 65, 63 & 64). Install
bonding lead (item 37) across upper
splice using two gear clamps (item 47).
See Figure 2-8.
(i) Insert the upper mast assembly (item
32) into the top of the mast insulator.
Insert the Install the 5/8 x 5” galvanized
bolt (item 66) into the bottom hole, just
above the weather protector assembly,
complete with flat washers (qty 5; 2 on
bolt head side, 3 on nut side), a split
washer and a nut (items 65, 63 and 64).
Place the two lugs from the lightning
bypass wires (from top and side of the
weather protector assembly) and one
galvanized flat washer (item 51) on a 3/8
x 5” galvanized bolt (item 55) and insert
into the middle hole just above the
weather protector assembly. Tighten in
place with 3 flat washers, a split washer
and nut (items 51, 50, 49). Insert the 5/8
x 4-1/2 galvanized eyebolt (item 48) into
the upper hole complete with a flat
washer and split washer (items 65 and
63). Thread on and tighten the 5/8
galvanized eye nut (item 52). Attach a
bonding lead (item 10) from the upper
CL40 Antenna Technical Instruction Manual Page 2-3
Section 2 Preparation for Use and Installation Issue 3.0
mast assembly (item 32) and the mast
insulator assembly (item 11) using two
gear clamps (item 61). Apply a bead of
silicone sealant where the upper mast
section inserts into the mast insulator.
See Figure 2-9.
NOTE
If you purchased the Top Loading Kit (Nautel
Part # 199-9085), refer to Figures 2-17 and 2-
18 to prepare your location and install the
foundation and guy wires. Use Table 2-3, not
Table 2-1, to configure the loading coils.
If you purchased the Guy Wire Kit (Nautel Part
# 199-9087), refer to Figures 2-17 and 2-19 to
prepare your location and install the foundation
and guy wires. Use Table 2-1 to configure the
loading coils.
If you purchased the Solar Light Mounting
Assembly (Nautel Part # 199-9086), refer to
Figure 2-19 for installation instructions. Install
this assembly before erecting the antenna.
(j) Lay out the six radials (item 7) in a
pattern approximating their final
configuration. Using the 2" stainless bolts
and stainless 'U' bolts (items 40, 41, 43 &
44) attach the radials to the mounting
ring (item 6) and mounting plate (item 5).
Replace any 1/4 SS nuts supplied with
the ‘U’ bolts with 1/4 SS locknuts (item
44). See Figure 2-10. Taking care not to
kink or twist the radial connector cable
assembly (item 3), insert each of the six
aluminium tips into the end of each
radial. Attach one vertical radiator (item
9) to the outer end of each radial using
the galvanized eyebolt supplied by
passing it through the pipe and
aluminium tip. Attach the loose end of
each radiator to the adjacent radial
connector assembly wire using the split
bolts (item 46). See Figure 2-11. Remove
the two 3/8 galvanized bolts from the end
of the upper mast section. If necessary,
raise the mast a further few feet. Slide
the radial assembly over the top of the
mast and align the two holes in the
mounting plate with the holes in the end
of the mast. Re-install the 3/8 galvanized
bolts and tighten firmly. Raise the mast a
further foot and place a wooden ‘A’ frame
(not supplied, see Figure 2-12) under the
upper mast. Lower the mast on to the
wooden frame until the mast is straight all
along its length. Attach three of the
vertical radiators to the 5/8 eye nut just
above the mast insulator and the
remaining three radiators to the eyebolt
on the opposite side. See Figure 2-9.
Use the stainless steel shackles
provided. Remove any slack by adjusting
the wire rope clip on each radiator.
Attach the loose end of each radiator to
the upper mast using one gear clamp
(item 47). Attach bonding lead (item 4)
between each radial and the upper mast
using six 9/16 to 1-1/4 gear clamps (item
45) and one 2-5/16 to 3-1/4 gear clamp
(item 47). See Figure 2-10.
(k) Mount two mounting bracket assy (item
29) on A1 using 4 - 3/8 x 1 stainless steel
bolt (item 59) with 4 galvanized flat
washers (item 51) and 4 galvanized lock
washers (item 50). Before securing the
mounting bracket assy install 8 - 3/8 x 6”
galvanized carriage bolts (item 58)
through the square holes of the mounting
bracket assy. Mount the loading coil
enclosure (A1, see Figure 2-13) 18”
below the weather protector using two
mounting bracket assy (item 29), two
mounting bracket back plates (item 35),
the 8 previously installed 3/8 x 6”
galvanized carriage bolts (item 58) with
flat washer, split washer and nut (items
51, 50, 49). Position it so the output
connector points up. The bottom of the
enclosure has a drain plug.
(l) Enter the carrier frequency in Table 2-1
(use Table 2-3 if you have the Top
Loading Kit) to determine the
configuration of loading coils L1A and
L1B. Connect the loading coils for series
or parallel configuration then connect
wires (provided in the ancillary kit) to the
appropriate input and output taps of the
loading coils. See Figures 2-14a & 2-14b
for connection examples.
Page 2-4 CL40 Antenna Technical Instruction Manual
Issue 3.0 Section 2 Preparation for Use and Installation
Table 2-1: Loading Coil Configuration versus Frequency (Standard Antennas)
(use Table 2-3 if you purchased the Top Loading Kit)
Freq
(kHz) Configuration L1A
(in) L1A
(out) L1B
(in) L1B
(out)
190-200 series 1 20 1 19
201-215 series 1 19 3 18
216-230 series 2 18 3 17
231-245 series 2 16 3 16
246-260 series 1 15 4 15
261-275 series 1 14 5 15
276-290 series 1 13 6 15
291-305 series 2 12 6 15
306-320 series 1 11 7 15
321-335 series 1 11 7 14
336-355 series 2 10 7 14
356-370 series 2 9 7 14
371-390 series 2 8 7 14
391-410 parallel 1 20 1 19
411-425 parallel 2 19 1 18
426-440 parallel 2 18 2 18
441-455 parallel 1 17 2 17
456-470 parallel 2 17 3 17
471-485 parallel 1 16 3 16
486-500 parallel 1 16 4 16
501-515 parallel 2 15 4 16
516-530 parallel 2 15 4 15
531-545 parallel 2 14 4 15
546-560 parallel 2 14 4 14
561-575 parallel 2 13 4 14
576-595 parallel 2 13 5 14
596-610 parallel 2 12 5 14
611-630 parallel 1 12 6 14
631-645 parallel 1 11 6 14
646-725 parallel 1 9 7 14
726-800 parallel 2 8 8 14
801-875 parallel 2 8 9 14
876-975 parallel 1 7 10 14
976-1075 parallel 2 6 10 14
1076-1150 parallel 1 6 11 14
1151-1250 parallel 1 5 11 14
1600-1700 parallel 2 4 12 14
1701-1800 parallel 1 3 12 14
See Figures 2-14a &
2-14b for shaded
connection examples
CL40 Antenna Technical Instruction Manual Page 2-5
Section 2 Preparation for Use and Installation Issue 3.0
(m) Attach the wire assy (item 8) between
the enclosure’s output connector and
the upper mast section. Use 2 gear
clamps (item 47). Shape the wire assy
so it is at least 6” from the enclosure.
Attach the down lead assembly (item
16) to the enclosure’s lower
connection. Use the hex key (Nautel #
HY66) in the ancillary kit to terminate
items 8 and 16 to A1. Attach the down
lead to each down lead insulator assy
(item 18) using the clips on the down
lead insulator. Shape the down lead
so it is clear of the mast. Remove any
slack and kinks in the down lead and
pull as straight as possible. Leave the
lower end loose for now. Place the top
clamp assembly (item 21), less the
outer saddle, over the top of the
anchor post. See Figure 2-4.
(n) Install the two ATU mounting bracket
assemblies (item 22) to the back of
the ATU using the hardware existing
on the bracket assemblies. This may
require relocating and reversing the
four mounting angles to the back of
the ATU. Attach the ATU to the
anchor post below the top clamp
assembly such that the winch handle
will clear freely. See Figure 2-16.
(o) Winch the antenna into its final position.
NOTE
Do not raise the antenna if local winds are
greater than 10 mph (16 kmph).
Using a steady, even action on the
winch to avoid excessive flexing of the
mast, raise the antenna to its vertical
position. Position the top clamp
assembly so it does not interfere with
the swing of the winch handle. Install
the outer saddle and snug up the nuts
just enough to hold the assembly in
place. Install the outer saddle on the
bottom clamp assembly and firmly
tighten. Adjust the verticality of the
mast as required. Firmly tighten the
top clamp assembly. Attach the down
lead to the output insulator on the top
left side of the ATU. Bend the down
lead as shown to provide a drip loop.
See Figure 2-2.
(p) If a ground plane (item 27) has been
purchased install it as shown in Figure
2-15a (30 radials) or 2-15b (60
radials). Make all joints by wrapping a
minimum of four turns of one wire
around the other and soldering.
(q) For a concrete base, drive the ground
rod (item 24) into the ground within
two feet of the base. For a non-
standard base, provide a low-
resistance termination point (not the
ground plane) near the base. Connect
the ground wire assembly (item 14) to
the bottom of the lower mast section
using the 3/8 x 1 galvanized hex head
bolt (item 56) complete with 3/8
hardware (items 51, 50 & 49).
Connect ground wire (item 36) and the
three polyethylene covered wires from
the ground plane to the ground bolt on
the bottom left of the ATU. Use the
ground rod clamp (item 25), or other
suitable means, to connect the ground
wires from the lower mast (item 14)
and the ATU (item 36) to the ground
rod (item 24) or low-resistance
termination. See Figures 2-1 and 2-5.
NOTE
The ground mat (see Figure 2-15a or
2-15b) forms an integral and necessary
part of the antenna system, providing the
return path for RF current flow. Avoid any
alteration to your particular configuration
as it will likely reduce antenna efficiency.
(r) Antenna erection can be done by
vehicle or block and tackle, using the
anchor post as a gin pole (see insert
in Figure 2-1). It is necessary to attach
some form of guide device to the top
of the anchor post to keep the hoist
cable in position. Whatever method is
used, attachment to the mast must
always be via the lifting bracket.
Page 2-6 CL40 Antenna Technical Instruction Manual
Issue 3.0 Section 2 Preparation for Use and Installation
2.5 ADJUSTING THE SPARK GAP
Adjust the antenna’s spark gap (see
Figure 2-7) as follows:
(a) Perform the necessary turn-on and
adjustment procedures for the
transmitter and ATU – as described
in their respective Technical
Instruction manuals – to achieve the
desired operating power level.
(b) Record the antenna current on the
ATU control/monitor PWB’s meter.
(c) Turn the transmitter off.
(d) Determine the antenna reactance
(XC) using Table 2-2.
Table 2-2: Antenna Reactance vs Freq.
(based on 220 pF antenna capacity)
Freq.
(kHz) XC(Ω) Freq.
(kHz) XC(Ω)
200 3618 375 1930
225 3216 400 1809
250 2894 425 1703
275 2631 450 1608
300 2412 475 1523
325 2226 500 1447
350 2067 535 1352
(e) Calculate the peak output voltage
(VPK) using either:
•DGPS: VPK = 1.414 IA XL
•NDB: VPK = 1.414 IA XL (1+Mod %/100)
I
A is the current recorded from step (b)
X
Lis the reactance from step (d).
WARNING
Turn the transmitter off when making
adjustments on the antenna. Lethal
voltages are present when any level of
RF is applied to the antenna.
(f) Enter the graph below with the peak
antenna voltage calculated in step (e)
and determine the spark gap length.
If you purchased the Top Loading Kit,
multiply the peak voltage (VPK) result
by 0.6.
(g) Lower the antenna. Set the spark gap
for the length determined in step (f).
(h) Raise the antenna, turn on the
transmitter at the desired power level
and ensure no spark gap arcing.
2.6 ANTENNA MAINTENANCE
Nautel recommends you perform a
thorough visual inspection of the antenna
at least once every six months.
•Check bolts and electrical connections.
•Check the base for cracks and heaving.
•Check the anchor post for excessive
movement within the base.
•Check the mast’s verticality and the
mast and radiator for any distortion or
unusual vibration. If necessary, take the
appropriate remedial measures.
•If the antenna is located near salt water
or in an area of high air pollution,
undesirable deposits may build up on
the insulator which, in turn, may impair
its performance. If the insulator
becomes visibly fouled, turn off the RF
input signal to the antenna and wash
these items with clean, fresh water.
•Give the winch a generous coating of
grease. Alternatively, if frequent raising
and lowering of the antenna is not
expected, dismount the winch and store
it inside.
100
60
40
20
10
6
4
2
.01 .02 .04 .1 .2 .4 1
Peak Antenna Volta
g
e
Gap Length
CL40 Antenna Technical Instruction Manual Page 2-7
Section 2 Preparation for Use and Installation Issue 3.0
Figure 2-1: CL40 Antenna (Lowered Position)
CL40 Antenna Technical Instruction Manual Page 2-8
Section 2 Preparation for Use and Installation Issue 3.0
Figure 2-2: CL40 Antenna (Fully Assembled, Raised Position)
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