Campbell 38485 User manual

05/2021
Copyright © 2021
Campbell Scientific, Inc.

Table of contents
1. Introduction 1
2. Specifications 1
3. Precautions 2
4. Siting 3
5. Installation 3
6. Surge protector kit (optional) 5
6.1 Surge protector enclosure installation 6
6.2 Outdoor surge protector installation 7
6.3 Troubleshooting the surge protector 10
Table of contents - i

1. Introduction
The 38485 antenna is a wideband, dual-port, directional-panel antenna with slant 45 polarization
that covers US LTE700/Cellular/PCS/AWS/MDS and global GSM900/GSM1800/UMTS/LTE2600
bands. The antenna is designed for fixed installations and is ideal for both indoor and outdoor
applications. It includes a UV-stable enclosure that provides years of use without degradation to
either mechanical properties or aesthetics.
This antenna boosts both the received and sent signals to and from the attached cellular modem
in a single direction. Because of its directivity, it can reject adjacent unwanted side signals,
allowing for better signal reception while rejecting interference from adjacent signal sources. This
high-gain, directional antenna has a narrow beam width that requires precise aiming at the
cellular tower or Wi-Fi access point.
2. Specifications
The peak gain, standing wave ratio (SWR), and beam width specifications are frequency specific
and provided in Table 2-1 (p. 2).
Operating temperature range: –40 to 70 °C (–40 to 158 °F)
Storage temperature range: –40 to 85 °C (–40 to 185 °F)
Operating frequency range: 698 to 960 MHz; 1710 to 2700 MHz
Impedance: 50 ohm
Isolation >25 dB
Front/back ratio: 21 dB
Maximum input power 50 W (per port at 25 °C)
38485 4G/3G 9 dBi MIMO Cellular Antenna 1

Polarization Slant ± 45°
Wind rating (operating) 150 km/h (93 mph)
Bands: US LTE700/Cellular/PCS/AWS/MDS
Global FSM900/SM1800/UMTS/LTE 2600
WiMAX 2300/2500
Radome and base material: UL94 V0 rated (UV-resistant)
Radome and base color: White
Ingression protection: IP55
Connector type: Dual Type N female
Bracket mast diameter: 1.5 to 3 in
Dimensions: 295 x 295 x 82 mm (11.61 x 11.61 x 3.23 in)
Weight 1.46 kg (3.22 lb)
Table 2-1: Peak gain, standing wave ratio (SWR), and beam width specifications
Frequency Peak gain
(typical)
Peak gain
(maximum)
Average
SWR
Horizontal 3 dB
beam width
Vertical 3 dB
beam width
700 MHz 8.7 dBi 9.1 dBi < 2.0:1 65 to 74 ° 66 to 70 °
850 MHz 9.0 dBi 9.7 dBi < 1.9:1 59 to 65 ° 61 to 65 °
900 MHz 9.8 dBi 10.4 dBi <1.7:1 57 to 60 ° 56 to 60 °
1800 MHz 7.5 dBi 8.5 dBi < 1.6:1 56 to 85 ° 57 to 84 °
1900 MHz 8.5 dBi 9.1 dBi <1.5:1 52 to 64 ° 46 to 62 °
2100 MHz 8.4 dBi 9.1 dBi <1.5:1 52 to 82 ° 46 to 72 °
2300 MHz 9.5 dBi 10.1 dBi <1.6:1 58 to 63 ° 57 to 66 °
2600 MHz 9.7 dBi 10.0 dBi < 1.8:1 48 ° to 54 ° 48 ° to 55 °
3. Precautions
Please read all instructions carefully before attempting to install and use this product.
The 38485 and all associated equipment should be installed in accordance with applicable local
and national electrical code guidelines to ensure safe operation.
38485 4G/3G 9 dBi MIMO Cellular Antenna 2

4. Siting
For best results, mount the 38485 facing towards the center of the coverage area with a clear
line-of-sight path between the antenna and active floor. Avoid mounting next to a column or
vertical support that could create a shadow zone and reduce coverage. A clearance of 0.91m
(3ft) around the antenna is recommended.
5. Installation
The 38485 includes a mount assembly that secures the antenna to a mast or pole using hose
clamps and mast mount adapter. The antenna can also be directly mounted on a wall (see
FIGURE 5-3 (p. 4) for drilling dimensions and orientation). Mount the antenna with the cable
connectors facing downward. Route cables between the base plate ribs and through the radome
notch.
FIGURE 5-1. Wall/mast mounting bracket
Mast mounting:
1. Fasten the hose clamps to the mounting bracket.
2. Slide the antenna onto the bracket and tighten the two bracket screws.
38485 4G/3G 9 dBi MIMO Cellular Antenna 3

3. Use the hose clamps to secure the antenna to the mast or pole.
FIGURE 5-2. 38485 mounted on a tower
Wall mounting:
FIGURE 5-3. Wall mounting bracket: drilling dimensions and orientation
38485 4G/3G 9 dBi MIMO Cellular Antenna 4

6. Surge protector kit (optional)
Campbell Scientific recommends installing two 31317 Surge Protection Kits—one for each
antenna port. The 31317 Surge Protection Kits are not included with the antenna and must be
purchased separately.
The 31317 Surge Protector Kit includes the following:
lPolyphaser protector
lRG174/U Antenna Cable, Type N Male to SMA Male (type N male connector fastens to the
to the Polyphaser protector connector; the SMA male connector fastens to the antenna)
lGround lug and wire assembly (position the lug between the connector and the enclosure
wall or secure the lug using the nut and lock washer supplied)
lSurge protector flange mounting bracket and hardware for securing the polyphaser
protector to an enclosure backplate
Campbell Scientific surge protector kits protect RF equipment by equalizing the potential
difference between the center pin of the coax cable and its shield. The kits include a capacitive-
coupled gas tube protector with multi-strike capability. If properly grounded, the capacitor will
38485 4G/3G 9 dBi MIMO Cellular Antenna 5

block low frequency surge currents induced onto the center-pin from the antenna side until the
gas tube reaches a high enough voltage to shunt the surge to ground.
The protector gas tube lies between the center conductor and the coax cable shield. During a
surge event, the gas tube raises the center conductor potential to the same potential as the
shield. Once the center conductor and shield are equalized, current cannot flow between the
circuitry connected to the center conductor and the shield/equipment chassis ground, thus
protecting the equipment.
6.1 Surge protector enclosure installation
1. Use grommet and screw to secure the bracket to the enclosure backplate.
2. Place the O-ring on a connector of the Polyphaser protector.
3. Insert that connector through the large hole in the bracket.
38485 4G/3G 9 dBi MIMO Cellular Antenna 6

4. Place the washer, ground lug ring, and nut on the connector.
5. Connect the ground lug wire to the enclosure ground lug.
6. Connect cables to the Polyphaser protector, cell modem, and antenna.
6.2 Outdoor surge protector installation
Required equipment:
lRoll of self-vulcanizing tape (cold shrink tape), 25 mm x 3 m (1 inch x 10 feet)
lScissors or tool for cutting the tape
38485 4G/3G 9 dBi MIMO Cellular Antenna 7

lCleaning supplies to clean the surge protector and connections
l31317 Surge Protector Kit
Procedure for connection:
1. Inspect connection components. If connectors are contaminated with dust, oil, or
corrosion, thoroughly clean the connections without introducing liquid onto cable ends.
Consider replacing connectors that have significant corrosion or cables that may have
become water or oil soaked.
2. Clean the body of the Polyphaser protector.
3. Connect the Polyphaser protector to the antenna and use a SWR meter to ensure the
measured surge protector value is in the 1.1:1 SWR range, which meets the protector SWR
specification.
4. Place the washer, ground lug ring, and nut on a Polyphaser protector connector.
5. Connect cables to the Polyphaser protector.
38485 4G/3G 9 dBi MIMO Cellular Antenna 8