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No part of this manual may be copied, transcribed, translated or reproduced in any manner or form whatsoever, for 
commercial purposes, without obtaining prior written permission from Barrett Communications Pty. Ltd. However, 
limited copying is permitted for private use providing authorship is acknowledged. 
 
The 2018 Mobile magnetic loop HF antenna design is protected by Australian patent 2001100423.  Unlicensed 
replication of the design is expressly forbidden. 

 

BCM201800/6 

 
 

© Barrett Communications 

 

 

Head Office: 

 

Barrett Communications Pty Ltd 

47 Discovery Drive, Bibra Lake, WA 6163 Australia 

Tel: +61 8 9434 1700  Fax: +61 8 9418 6757 

Email: 

[email protected]

 

 

www.barrettcommunications.com.au

 

 

Summary of Contents for 2018

Page 1: ...for private use providing authorship is acknowledged The 2018 Mobile magnetic loop HF antenna design is protected by Australian patent 2001100423 Unlicensed replication of the design is expressly forbidden BCM201800 6 Barrett Communications Head Office Barrett Communications Pty Ltd 47 Discovery Drive Bibra Lake WA 6163 Australia Tel 61 8 9434 1700 Fax 61 8 9418 6757 Email information barrettcommu...

Page 2: ...p the Roof Rack 12 Preparing the Vehicle 15 Fitting on Vehicles Without Gutters 17 Setting Up the Roof Rack 17 Preparing the Vehicle 18 Maintenance 21 Removal of Rack 21 Retrofitting the 2018 Barrett Mobile Magnetic Loop Antenna 21 Cabling 22 Operation 23 To Deploy the Antenna 23 To Stow the Antenna 24 Barrett Transceiver to 2018 Barrett Mobile Magnetic Loop Antenna Setup 25 Supported Barrett Tran...

Page 3: ...3 of 31 J5 Jumper Settings 29 J6 Jumper Settings DC Supply on RF Cable 29 J7 Jumper Settings 29 Parts List 30 Technical Specifications 31 ...

Page 4: ...nstall Installation is therefore quicker and cheaper and the system can be moved simply between vehicles Free roof rack with every package The antenna can be used as a conventional roof rack for storing luggage Eliminates Skip Zones A HF system that can be used in ranges from 0 1 000 km and more Increased immunity to ignition and power line noise Broadband low noise scan amplifier 4 of 31 ...

Page 5: ...l gain over whip antenna systems varies between 10 dB and 14 dB The benefit to the user is that it radiates significantly more power and magnifies received signal strength giving overall performance much higher than can be achieved from any vehicle whip antenna system The 2018 Mobile magnetic loop HF antenna tuner unit is a highly efficient continuously variable capacitor unit which is driven by a...

Page 6: ...nications representative The Guide also covers the basic principles of installation However we recommend that the installation of your 2018 be carried out by a qualified Barrett Communications representative Glossary of Terms ATU Antenna Tuning Unit HF High Frequency kHz Kilohertz measure of frequency km Kilometre MHz Megahertz measure of frequency PEP Peak envelope power PTT Press To Talk Selcall...

Page 7: ...rs require adequate supply current It is essential that the supplied cables are utilised to reduce the likelihood of system malfunction Please use the specified cables Radio Frequency Field Exposure The 2018 Barrett Mobile Magnetic Loop Antenna produces high localized radio frequency fields As long as personnel are beneath the level of the roof rack exposure to fields will be well below safe opera...

Page 8: ...tant Do not use the antenna arm to tie any object down Keep goods at least 0 3 m away from antenna arm and feed cables Frequency Hopping Use 8 of 31 Due to the narrow operating bandwidth of the loop antennae they are not ideally suited for frequency hopping use However at higher frequencies approximately 7 MHz and when there is adequate signal to noise ratio adequate results may be obtained Operat...

Page 9: ... interference from adjacent power lines providing greater communication clarity The 2018 Barrett Mobile Magnetic Loop Antenna can be fitted to almost any surface The roof rack comes in a range of mounting bracket options Solutions are available that will allow clamping to the roofs of 4WD s sedans buses trucks and prime movers It is designed to minimise head wind noise with an angled deflector mou...

Page 10: ... the associated receive transmit switching are incorporated within the ATU A simplified block diagram of the circuit is shown below 10 of 31 Stepper motor Microprocessor control Scan amplifier Antenna Radiation resistance ohmic losses Variable capacitor RF feedbox Voltage sample SWR detector Transceiver To microprocessor Antenna tuner Transmit receive switching The antenna is effectively a paralle...

Page 11: ...x8 M10 Flat Washer x16 M10 Star Washer x16 M10x25 Hex Bolt x16 M10x30 Hex Bolt for leg spacer U Bolt x8 Nylon x16 Full Gutter Support x16 Full Gutter Support Nylon x16 Locating Rod welded Clamp x8 M6 Flat Washer x16 M6 Nyloc Nut x16 M6 PVC Cap x16 M10 Strut Nut x16 Leg Spacer Viewing Hole Leg Mount x8 M10 Flat Washer x16 M10 Star Washer x16 M10x25 Hex Bolt x16 M10x30 Hex Bolt for leg spacer U Bolt...

Page 12: ...ut Nut Mounting Channel M10 Washer Serrated Grooves Turned down lips M10 Bolt M10 Star Washer Part of Leg Mount Strut Nut Mounting Channel M10 Washer Serrated Grooves Turned down lips Important Ensure each strut nut is rotated 90 and the serrated grooves in the strut nut located into the channel s turned down lips There is a viewing hole located on the leg mount to check that the strut nut has rot...

Page 13: ...tions A D if necessary A B C D The measurements A D vary according to the vehicle type Use the supplied chart in the above diagram to determine these Use a straight edge to line up the centre legs before tightening Double check the tension on all bolts Note Nylon channel pieces should be fitted to the tops of each clamp as shown in the exploded diagram on page 11 13 of 31 ...

Page 14: ...t Ensure the feed cable is not damaged by being trapped between the ski bar mount and the roof rack shown below The correct position for the cable running underneath the ski bar mount is shown below 8 9 14 of 31 ...

Page 15: ...el Full Gutter Support Roof Turret Nylon Channel The rack may be lifted onto the vehicle by two people one either side However it is preferable for a third person to help at the rear of the rack Lift by the bottom of the leg mounts Note The sloped edge of the antenna faces towards the front of the vehicle i e the RF Feedbox is at the front and the Tuner Box is to the rear Position the rack into th...

Page 16: ...heck the clamps are sitting flat against the underside of the surface and tighten until the door seals clear See the illustration below Note On some vehicles the hinge bolts of the doors may require loosening and the door and latch lowering Contact your Barrett Communications representative if you have any problems Barrett Communications Pty Ltd accepts no liability for damage to door seals as cor...

Page 17: ...ps M10 Bolt M10 Star Washer Part of Leg Mount Strut Nut Mounting Channel M10 Washer Serrated Grooves Turned down lips M10 Bolt M10 Star Washer Part of Leg Mount Strut Nut Mounting Channel M10 Washer Serrated Grooves Turned down lips Important Ensure each strut nut is rotated 90 and the serrated grooves in the strut nut have located into the channel s turned down lips There is a viewing hole locate...

Page 18: ...of The standard size roof rack uses all six points Locate the hooks on the inner side of the rubber strips on the roof There are three hooks per side The roof rack clamp has a slot at the bottom which the hook passes through Make sure the hook is the correct way round Temporarily hold the clamp in an upright position with the masking tape as shown in the following diagram so the rack can be placed...

Page 19: ...amp Rubber Strip Leg Support Rail The rack may be lifted onto the vehicle with two people one either side but it is ideal to have a third person at the rear for extra stability Lift the rack carefully over the roof from the rear and position the legs into the leg support rails Refer to the following diagram Clamp Rubber Strip Located into the Leg Support Rail Vehicle Clamp Rubber Strip Located int...

Page 20: ...m Rubber Strip removed from drawing for clarity Rubber Strip removed from drawing for clarity Rubber Strip removed from drawing for clarity Ensure the U bolt is hooked above the welded locating rod on the inside of the leg mount then tighten firmly without deforming the clamp bracket Place PVC caps over the threaded ends of the U bolt Refer to the following diagram Note The Nyloc clamp nuts can ea...

Page 21: ...0 or similar penetrating oil on the thread of exposed fasteners giving it time to be absorbed before attempting to loosen them Remove the Nyloc nuts slowly to stop the threads from binding Retrofitting the 2018 Barrett Mobile Magnetic Loop Antenna If you are fitting the 2018 Barrett Mobile Magnetic Loop Antenna system to your existing rack ensure that there is no paint or corrosion between the cab...

Page 22: ... to an area close to the point of entry into the vehicle and then cable tied to the rack Both cables should then be passed through the split convoluted conduit for protection before being fed through the entry point into the vehicle Once the cables have been mated with the connectors on the 2018 HF antenna seal them with self amalgamating tape to prevent water ingress The coax cable from the RF fe...

Page 23: ...owered It also must not be operated in the down position To Deploy the Antenna Undo the clip that secures the antenna to the roof rack located on the rear right hand edge looking at the vehicle head on Side Clip Rear of vehicle Side Clip Rear of vehicle Side Clip Rear of vehicle Unhinge the antenna from the roof rack to the fully upright position by releasing the clip at the bottom of the high vol...

Page 24: ...From the roof rack Reset the clip to its locked position when the boom is vertical to prevent it falling over during operation To Stow the Antenna Simply reverse the directions for elevating the antenna The image below shows the antenna folded down and secured using the side clip 24 of 31 ...

Page 25: ...hear the motor in the ATU cycle back and forth briefly Following this tune cycle the receiver noise level may be increased and if the signal level meter is active on the transceiver an increased signal level may be observed When switching on the ATU will set itself for operation at its highest frequency if not already in that position and the scan amplifier will be activated After observing that t...

Page 26: ...nce The input power must be between 2 W and 10 W for the ATU to be able to tune Check that all heavy ring tag connections on the roof rack and ATU are securely fastened If the unit still does not tune unplug the 6 pin control cable undo the four lid screws and remove the lid ensuring no water or other contaminants fall inside Check all connectors are plugged into their sockets on the PCB Assembly ...

Page 27: ...d the antenna arm at the rear Slide the toroidal sensor over the cable and refit it securely in place Attach the optic fibre to the meter Choose a frequency within the 2018 s operational band initiate a tune sequence and observe the reading on the meter Take measurements over the band noting the deflection remains greater half scale of the meter display Once tuned key the radio and talk into the m...

Page 28: ...12V supply B GND Signal Ground C TUNE Pulled low when tuning returns high when tuning completed D SCAN Indicates scan amplifier on Active high E N C F N C Internal Jumper Configurations View of 2018 Mobile magnetic loop HF antenna PCB Component Side Overlay 1 J5 J4 J2 J3 J7 A B C J6 J1 28 of 31 ...

Page 29: ...J5 Jumper Settings 24V 12V J6 Jumper Settings DC Supply on RF Cable DC supplied No DC supplied J7 Jumper Settings A B C 29 of 31 BARRETT ...

Page 30: ...ed box Cable SA 55060 Antenna Arm Ground Cable SA 55061 Antenna Arm HV Cable SA 55062 ATU Ground Cable SA 55059 Delrin Insulator PW 57136 2018 Mobile magnetic loop HF antenna 2018 00 01 and BC201801 2018 Mobile magnetic loop HF antenna to transceiver control cable to suit 2050 transceiver 2018 01 01 ...

Page 31: ...Tuning method Continuously variable tuning Drive method Precision stepper motor Tune point Best VSWR reading Antenna bandwidth 40 kHz 3 9 MHz 280 kHz 12 5 MHz Scan amplifier noise 11 dB above thermal Rx 3rd order intercept 25 dBm 1 dB compression 10 dBm Temperature Operating 30ºC 60ºC Storage 30ºC 80ºC Humidity 95 non condensing Dimensions 1900 mm x 1250 mm x 170 mm stowed 1900 mm x 1250 mm x 780 ...

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