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Congratulations! - Primus Electronics Corporation

4 TH QUARTER 2012

Congratulations!

THE WOMEN OF VERTICAL LIMIT

ARE ON THE JOB AND WEARING PRIMUS!

All pictures were taken at the Vertical Limit World Headquarters in Wanamingo, MN


Congratulations!

THE WOMEN OF VERTICAL LIMIT

ARE ON THE JOB AND WEARING PRIMUS!

About Vertical Limit Construction, LLC:

Vertical Limit is a national leader in technical and construction

services to the Wireless, Energy, Infrastructure,

and Government industries. With unmatched

capabilities, national footprint, Midwest work ethic,

high integrity, and a get it done attitude, Vertical Limit

brings a true single source partner to the table. The

company's systems-based and practical approach is

the cornerstone of their business. Their unique blend

of cutting edge technology and people that work like

your grandpa used to - are the strengths that they

have become known for today.

Vertical Limit's experience shows in every project they

manage. They know that quality is more than just the

finished product, it is in the details and discipline of

doing it right the first time. Their employees are not

only experts in their field, but they take a personal

sense of pride in a job well done.

For more information on all of the services they offer,

contact Vertical Limit today at (877) 924-1222 or visit

www.verticallimit.com.

All pictures were taken at the Vertical Limit World Headquarters in Wanamingo, MN

2 PrimeConnection | 4 TH QUARTER 2012

Anritsu SiteMaster TM Certified Line Sweep Training 2-Day Course, $1,350 pp

October 30-31 in Joliet, IL | November 27-28 in Joliet, IL | December 18-19 | Joliet, IL

CITCA Fall Protection Training

Oct 22: Authorized Climber | Kankakee, IL | $429 pp

Oct 23-25: Tower Rescue & Competent Climber | Kankakee, IL | $1,399 pp

Oct 26: Train-the-Trainer (for Tower Rescue or Authorized Climber) | Kankakee, IL | $799 pp

Nov 26: Authorized Climber | Kankakee, IL | $429 pp

Nov 27-29: Tower Rescue & Competent Climber | Kankakee, IL | $1,399 pp

Nov 30: Train-the-Trainer (for Tower Rescue or Authorized Climber) | Kankakee, IL | $799 pp

For more information on any of these trainings or to register online, visit www.primuselectronics.com

or contact Shannon with Primus at (800) 435-1636 or shannon@primuselectronics.com.


PRIMUS ELECTRONICS

4180 E Sand Ridge Road | Morris, IL 60450

(800) 435-1636 tel | (800) 767-7605 fax

PRESIDENT

Michael Johnson

OUTSIDE SALES

Chris Pleibel

Regional Sales Manager - Northeast Region

(610) 745-4491

cpleibel@primuselectronics.com

Rob Menees

Regional Sales Manager - Midwest Region

(217) 840-1887

site-specific@comcast.net

Gerry Fritzke

Regional Sales Manager - Northwest Region

(360) 921-5945

gerryfritzke@comcast.net

Diane Mueller - Tower Sales Representative

(815) 351-0355

dmueller72@aol.com

Gordon Nelson - Territory Manager NE

(301) 785-7740

gnelson@primuselectronics.com

Doug Melander - Territory Manager Midwest

(765) 721-5580

dougmelander@gmail.com

Adam Cummins

Business Development Manager - Northeast

(215) 858-7103

acummins@primuselectronics.com

Gabe Dixon - Business Development

Manager National Programs

(847) 732-5885

gabe@primuselectronics.com

SALES AND MARKETING

Doug Salvatori - Product Development Manager

Ryan Dixon - Inside Sales Manager

Shannon O’Connor - Marketing Manager

EDITORIAL CONTRIBUTORS

Bird Technologies, CommScope, Bogdan

“Bogey” Klobassa with Times Microwave,

Anritsu Company, Protection Technology

Group, NewMar, and Gordon Nelson, Steven

Larson, and Shannon O’Connor with Primus

INSIDE THIS ISSUE

By Gordon Nelson,

Primus

in Wireless

6

Welcome

A Lightning Protection

System for Wireless

Telecom Sites

By Bogdan “Bogey”

Klobassa Times Microwave

Congrats

Adorable baby Candon James Farber,

grandson of employee DeeDee

Wignes, was born August 17

weighing 7 lbs, 11 ounces and 20''.

Congratulations DeeDee!

Surge & Safety

Protection for Railway

Communications

8 14

By Protection Technology Group

EDITOR

Shannon O’Connor, Marketing Manager

ON THE COVER

The Women of Vertical Limit Construction

in Wanamingo, MN

WANT A FREE PRIMUS T-SHIRT and a

CHANCE TO APPEAR ON OUR COVER

Show your industry pride with a free Primus

LIVE LEGENDARY t-shirt saluting the professional

accomplishments in the telecommunications

industry. Call us with your company

name, address, and sizes requested. If you

have additional questions or comments, call

(800) 435-1636.

Jonathon Biskie

Inside Sales Representative

jonathan@primuselectronics.com

Todd Coyl

Warehouse Team Member

Joe Gonzales

Dave Rura

Warehouse

Team Members

Robert Fessler

Warehouse Team Member

The Difference in Wireless Distribution

PrimeConnection is published as a corporate communications magazine for customers and friends of Primus Electronics. The

magazine is published four times a year in January, April, July, and October by Shannon O’Connor, Marketing Manager, Primus

Electronics, at 4180 E Sand Ridge Road in Morris, IL. To change your mailing address or request additional copies, please call

(800) 435-1636 or email shannon@primuselectronics.com.

3


Configuring Bird Technologies’ Model 43 for MOTOTRBO TM

By Bird Technologies

he model 43 wattmeter has been a

staple for power measurement in

two-way communication systems,

providing accurate measurements

for analog signals for the past 50 years.

Modern communication techniques

have changed the way signals are modulated

so that they can carry more information

while using less power. These

complex modulation techniques utilize

various methods for increasing the data

rate or decreasing the required bandwidth.

MOTOTRBO was designed to reduce

costs by combining calls onto the

same bandwidth, thus doubling the possible

call volume.

While the model 43 can be used to

measure signals like MOTOTRBO,

it's important to understand the signals

coming out of the radios in order to configure

the wattmeter for the proper measurements.

MOTOTRBO utilizes a signal

format called Time-Division Multiple-Access

(TDMA) in order to add a second call

on the same amount of band space.

TDMA signals use multiple time slots of

data, taking turns using the bandwidth allocated

to the channel.

Since the switching occurs very fast,

there is no apparent drop in quality but

more calls can be made using one set of

equipment (repeater, antenna, etc).

In addition to adding a second call

to the line, power consumption of a single

call is reduced, as the second window is

turned off and doesn’t consume power.

Due to the switching between the

two calls, the envelope of the signal is not

constant and thus average power measurement

is not going to reflect the real output

of the radio. However, peak power can be

used as an accurate way to verify the output

of the radio regardless of how many

time slots are in use.

Using the 4300-400

Peak Power Retrofit Kit,

the model 43 can be configured

to make peak

power measurements

using the same elements

that are used for average

power.

When in this mode, measurements

of MOTOTRBO will be accurate and

will reflect the actual output of the radio.

The model 43 can still perform average

power measurements for the systems that

use analog modulation schemes, simply

by flipping a switch on the side of the

unit. Additionally, an internal battery allows

the unit to maintain its portability.

With the future of radio focused on

reducing the bandwidth required to communicate,

TDMA signals are going to become

more prevalent. MOTOTRBO is

a great example of how smarter signals

can be used to reduce infrastructure and

overhead.

With the proper upgrades, the

legacy model 43 can be used to verify

MOTOTRBO systems without losing any

functionality. Contact your local or preferred

radio dealer for

MO-

TOTRBO

inquiries.

Contact

Primus

for all of

your Bird

Technologies

product

needs

including

their popular

Model 43

Wattmeter.

4

PrimeConnection | 4 TH QUARTER 2012


Maximizing network productivity and

minimizing costs in locations that

produce extreme environmental conditions

requires antennas that are

tough as the environment. Introducing

the ExtremeLine family of antennas

from CommScope. Extreme

performance for the most extreme

environments, including:

High-wind areas

- Hurricanes | Typhoons | Extreme

Wind Gusts

Areas Prone to Corrosion

- Marine / Volcanic / Chemical

Process Plants / Fossil Fuel Power

Stations

Mountainous/Extreme Heights

Carefully modified in accordance with

EIA195 to provide excellent physical,

mechanical and electrical performance

under great stress, ExtremeLine

antennas:

- Exhibit a maximum deflection of 0.1

degrees in operational wind speeds

of up to 70 mph

- Feature up to 200 mph wind speed

ratings* with 1" of radial ice

- Demonstrate long-term reliability

within a temperature range of 58°–

158° F

*Survival wind speed is the maximum wind speed at

which there is no permanent deformation of the antenna

or any of its components.

THINK ALL MICROWAVE ANTENNAS ARE

DESIGNED THE SAME

By CommScope, Inc.

THINK AGAIN!

As Hurricane Isaac lumbered across the Gulf Coast, local communities prepared for the

storm’s arrival. Residents stocked up on flashlights and generators, bottled water and

canned foods, while local business owners boarded up windows in an attempt to defend

against the surging floods and battering winds they knew were imminent.

Wireless operators were also scurrying to stay ahead of the hurricane season, increasing

capacity, and equipping or readying their networks before any seasonal tornadoes

caused more major damage.

Although the immediate potential threat of damage is not as high, operators must also

contend with the prevention of damage to equipment that may never see the eye of a hurricane,

yet faces other extreme environmental conditions. While the various capacity-adding

components that comprise wireless networks must be durable and high-quality — products

configured into networks that exist in these harsh conditions deserve a special degree of attention.

Durable ExtremeLine Microwave Antennas

To combat rigorous weather conditions, CommScope® offers ExtremeLine, a family of

microwave antennas designed to deliver excellent performance and exceptional durability

in a majority of global climates. They feature a rugged, compact construction and highquality

materials, making them an excellent choice for increased productivity at minimal

expense amid the corrosive environment of an industrial complex, high atop a 12,000-foot

mountain or even deep within the eye of a roaring hurricane.

The ExtremeLine family consists of three series: W, WE and SE. Each distinctive series

provides a unique set of properties.

- W-Series Antennas: Carry wind speed ratings of 250 km/h (155 mph)

- WE-Series Antennas: Feature a wind speed rating of 250 km/h (155 mph) and also feature

a corrosion-protection package

- SE-Series Antennas: Feature a wind speed rating of 320 km/h (200 mph) in addition to the

corrosion-resistance package

Extreme conditions demand exceptional solutions

Whether your equipment faces hurricane-level winds or sub-zero temperatures, safeguard

your network investment with ExtremeLine microwave antennas. For more information or

to place an order, please call (800) 435-1636.

5


6

PrimeConnection | 4 TH QUARTER 2012


By Gordon Nelson, Primus

in Wireless

his year has seen several wireless carriers launching new build projects across the country. Companies such as AT&T, Sprint, Verizon, and

T-Mobile are all upgrading their networks in the rush to 4G, and the majority of these upgrades are being done using fiber optic cable.

Fiber is beginning to replace traditional coax as a means to transmit data up the tower to remote radio heads and antennas. As a result,

it is becoming increasingly important to understand the various types of fiber, fiber connectors, and jacketing, of which there are many. We

will go over the most common fiber options that are applicable to today’s wireless builds.

Single-mode vs Multi-mode

In general terms, fiber optic cable transmits

light over a strand (fiber) of transparent glass,

and can be either Single-mode or Multi-mode.

Single-mode fiber transmits a single ray

of light and is generally used for long distance

communication runs. Some common characteristics

are:

- A core diameter between 8 and 10.5 microns

- Higher data capacity than multi-mode

- A yellow colored outer jacket

- Used in outside plant application

- Used for long distance applications, generally

greater than one mile

Multi-mode fiber transmits multiple rays

of light and is generally used over shorter distances.

There are more varieties of multimode

fiber than single-mode fiber. The most

common characteristics of multi-mode fiber

are:

- A core diameter of 50 microns or 65 microns

- An orange or aqua colored outer jacket

- Used in short run applications, generally

under 1 mile

Most of today’s carrier network upgrades

involving fiber is being done with multimode

fiber.

Fiber Optic Connectors

At the termination point of each fiber, a connector

is used to interface the fiber with the

equipment it is transmitting data to. There are

many different fiber connectors, but the most

common connector types in wireless application

today are LC or SC connectors. These two

connectors have a similar appearance, with a

square head that is pushed onto the exposed

fiber and mechanically held to the connection

point using a retaining tab (much like a phone

or Ethernet connector).

LC and SC connectors can also be either

simplex or duplex connectors. A simplex connector

is a single connector, for a single fiber,

by itself. A duplex connector holds a pair of

fibers, each in their own housing, but mated

side by side.

Jacketing

Much like coax, fiber can be jacketed in several

ways based on its intended use. The three

most common jacketing types are:

OFNR (Optical Fiber, Non-conductive

Riser): Referred to as “Riser rated,” this jacket

is engineered to prevent the spread of fire

from floor to floor in a building. OFNR jacketed

fiber is most common in indoor applications

such as data centers, shelters, and indoor DAS

systems.

OFNP: (Optical Fiber, Non-conductive

Plenum): Referred to as “Plenum,” this jacket

is engineered to be fire-resistant and lowsmoke.

OFNP jacketed fiber is most common

in indoor applications such as data centers and

shelters where nearby air-circulation systems

are in use.

INDOOR/OUTDOOR: Indoor/Outdoor

rated jacketing contains a combination of armoring,

water resistance, and fire-resistance

that enables it to hold up to the elements in

various environments. Indoor/Outdoor jacketed

fiber is the most common type used on

outdoor cell sites.

As the use of fiber on the cell site becomes

more prevalent, it will be important to stay

informed of all the various characteristics and

components in play. The team at Primus is

always available to answer your questions and

fulfill your fiber needs!

7


PRODUCT SPOTLIGHT: TIMES MICROWAVE’S SMART PANEL ENTRY SYSTEM

A Lightning Protection System

for Wireless Telecom Sites

Site grounding is the foundation for effective

lightning protection at communications sites

By Bogdan “Bogey” Klobassa | Times Microwave

Several factors affect successful implementation

of lightning protection for wire-

to limit the differential voltage across an

tion device’s primary function is its ability

less networks, such as understanding equipment I/O port while conducting as

lightning-stroke characteristics, antenna much event current as possible to earth

site layout conditions, structural protection,

equipment protection and constructection

device will be affected not only by

ground. Performance of every surge protion

of a low-impedance ground system the manufacturer’s specification, but also

designed for fast lightning transient response.

method. Surge protection device perform-

to a great extent by the installation

Proper grounding and bonding design

play a critical role in the operation of test and an on-site test where the ground

ance differs significantly between a bench

every surge protection device installed on resistance and inductance of all grounding

a communications site. Proper design applies

without exception to all radio-fre-

the undefined protected load impedance at

and bonding connections, not to mention

quency (RF), data, telemetry, AC and DC the lightning frequency, are determining

input/output ports. Every lightning-protec-

factors.

High-resolution, Full-climatology Annual Flash Rate

The lightning event

More than 2,000 thunderstorms occur

throughout the world at any given time.

(See Figure 1.) They produce about 100

lightning flashes per second. Any lightning

strike can destroy a radio system that isn’t

properly grounded and protected. With

ever-increasing dependence on computers

and communications networks, protection

from system disruptions becomes essential.

Understanding the principles behind a

lightning event helps users properly design

system protection.

As heated air migrates upward into a

freezing region, it creates constant collisions

among ice particles in the thundercloud

driven by rising and falling air

columns, causing static charge buildup.

Eventually, the static charge becomes

sufficiently large to cause the air to break

down. An initial small charge called a step

leader breaks out, seeking an ideal cloudto-cloud

or cloud-to-earth path. Once this

path is established, the main series of

strokes follow.

Figure 1. This map shows the global distribution of lightning from April 1995 to February 2003 using the combined

observations of the NASA OTD (4/95–3/00) and LIS (1/98–2/03) instruments.

8 PrimeConnection | 4 TH QUARTER 2012

Statistical nature of lightning

The most basic forms of lightning are

cloud-to-cloud, intracloud and cloud-toground.

There are positive and negative

forms of this event. The step leader polarity

indicates whether the strike will have

Continued on page 10


Anritsu Company Introduces

New Generation of Site Master

Handheld Cable and Antenna Analyzer

Inventory Blowout Special on Anritsu’s S331D Cable

and Antenna Analyzers! See page 13 for details!

Primus is excited to offer customers Anritsu’s

new Site Master S331L Cable and Antenna

Analyzer, a new generation of rugged handheld

field instrumentation that builds off the

field-proven design and success of the Site Master

to provide high-performance cable and antenna

analysis quickly and accurately. Reliable, durable,

easy-to-use, and offering eight hours of continuous

battery life, the S331L is a cost-efficient tool for

tower contractors, installation and maintenance contractors,

and wireless service providers to ensure optimum

deployment, installation, and maintenance of

wireless networks.

The S331L, which covers 2 MHz to 4 GHz,

brings a high level of performance to return loss,

cable loss, and Distance-to-Fault (DTF) measurements.

It has the highest RF immunity of any Site

Master. A sweep speed per data point of 1.5 msec

(typical) saves technicians time and enables easier

identification of intermittent problems in real time.

Helping ensure measurement accuracy is the standard

built-in InstaCal, which provides fast oneconnection

calibration anytime, anywhere. The

S331L also features a standard built-in power meter,

for easy, convenient testing of RF power in field environments.

With eight hours of continuous battery life, the

S331L allows field technicians to conduct a full

day’s testing on a single charge. Intelligent powersaving

features – such as sleep mode and auto-display

brightness that automatically reduces the

screen’s backlight when the analyzer is not in use –

can extend battery life well beyond the continuous

eight hour rating.

The S331L features the field-proven Site Master

design. It is dust- and splash-resistant, has a

backlit 7-inch TFT touch screen display, and weighs

under 2 kg (4.4 lbs), including battery. The rugged

design and compact size make the S331L well suited

for any field application, including level ground,

climbing large towers, or climbing through a roof

hatch.

For more information or availability, call

Primus at (800) 435-1636. For a listing of Anritsu

Line Sweep certification classes, call Primus or visit

www.primuselectronics.com.

9


Continued from page 8

positive or negative characteristics. To

understand the statistical nature of the

event, system designers must evaluate

the following characteristics.

The current wave shape. This

specific wave shape shows the rate of

current rise to 90 percent of peak

value (front time), and diminishing

current duration to 50 percent of peak

value (time to half value). (See Figure

2.) The current wave shape consists of

the di/dt high-frequency component, as

well as the DC content. To provide

specific frequencies associated with this

wave shape, Fourier analysis should be

performed. Taking into account the 1–10

microsecond (μs) rise times, the event

could be characterized as DC – 1 MHz.

Peak current analysis. International

research data compiled during the past 40

years captures values and distribution parameters

of lightning currents. Looking at

50 percent distribution, the typical event

will carry peak currents in the 10–50 kiloampere

(kA) range. While planning for

site protection, these values are helpful in

analyzing protection needs for grounding

design, as well as determining ratings for

protectors applied on all I/O ports.

A lightning event can have as many

as 30 additional lower-current return

strokes based on the impedance of the

conductive channel and the charged

cloud’s ability to migrate electrons to the

discharge area. A typical lightning event

might have two or three low-energy return

strokes. Total energy conducted through

the struck object will be elevated as the

number of return strokes increases.

Continuing current. Any one of the

multiple return strokes can have the pulse

decay extended from 35 to 550 milliseconds.

During this extended time, continuing

lightning currents can cause damage to

equipment that might have survived the

Figure 2. Definitions of short-stroke parameters. Typically, T 2 is less than

2 milliseconds.

initial series of short, high-current pulses.

The long-duration DC surge following a

fast rise-time event will be reduced only

by the DC resistance of the cables. From

30 to 1,000 amps can be delivered to the

coaxial cable entry panel for 35–550 milliseconds.

Proper entry panel grounding is

essential.

Current rise time. The rate of rise

time to peak lightning current ranges from

a fraction of a microsecond to about 10 μs.

Understanding this characteristic is important

once one observes the inductive voltage

drop associated with the rate of

current rise. By taking into account the

lightning peak current, its rise time and the

tower inductance with coaxial cables, it is

easy to determine how much differential

voltage will be present.

Let’s assume 18 kA peak lightning

current with 2 μs rise time conducted to

ground by a 150-foot tower with approximate

inductance of 40 microhenries (μH).

The Vp = –Ldi/dt formula becomes handy.

The calculated total inductive voltage drop

across the tower will amount to about 360

kilovolts (kV). This voltage can be responsible

for flashover among towers, cables

and grounding jumpers, and can destroy

coaxial cable insulation.

Tower and coaxial cables will act as

a voltage-divider network. The associated

lightning currents will divide themselves

among the tower, cables and other conductive

surfaces of the installation. Figure

3 (on page 11) illustrates this inductive

voltage-drop phenomenon.

Site grounding principles

Coaxial cables and the tower, together

with all other service entries

into the communications shelter,

present low-impedance preferred

lightning paths to ground through

individual circuits. In all cases,

proper grounding, bonding and protection

techniques offer alternative paths for damaging

currents. The earth referenced as

ground is the electrical return for lightning

strike energy. It is nature’s balance for a

continuing sequence of natural phenomena.

Why is a lightning ground system

different from an AC power ground A

lightning ground system at a communications

site should disperse large amounts of

electrons from a strike over a wide area

with minimum ground potential rise

(GPR). GPR means any difference in voltage

within the strike’s local sphere of influence

(step potential).

Properly designed and implemented

lightning ground systems should be capable

of doing this quickly (fast transient response).

By spreading electrons over a

wide area, the step potential for any

smaller given area would be reduced. The

speed, or transient response of the ground

system, would depend on the geometry

and combined inductance and capacitance

of the below-grade conductive components

and the resistivity and conductivity

of the soil shunting those components. The

lower the inductance of the system components

and soil resistivity, the lower the impedance

will be at higher frequencies. A

lower-impedance ground system will disperse

electrons faster. A lightning ground

system can be an excellent AC power

10 PrimeConnection | 4 TH QUARTER 2012


ground, but an acceptable AC power nately, critical equipment might be in

ground might not be a good lightning place between the lightning strike energy

ground.

and a lower-potential current-return path.

Lightning strike energy that reaches One or two ground rods for a residence,

a ground loop around a commercial

the tower base and that travels through the

coaxial cables to the entry panel ground building, or a loop and three ground rods

can quickly saturate a ground system and around the base of a communications

elevate the electrical potential throughout tower might meet electrical code, but will

the site referenced to the outside world. not disperse the lightning strike energy

AC power, telephone, data, control and quickly enough to keep the GPR low.

alarm lines all represent paths to a lower Effort and money spent upfront on

electrical potential for lightning strike energy

coming from the tower. Unfortu-

and equipment damage. Additional atten-

proper grounding will reduce downtime

tion should be dedicated

to design,

Why Coaxial Cable Ground Kits Are Essential

implementation, maintenance

and integrity

of the site grounding

system.

All lightning-protection

devices, regardless

of the

technology used in

their designs, rely primarily

on a low-impedance

return path to

ground while conducting

surge current and

controlling the differential

voltage to protect

equipment. The

concept applies without

exception to all

Radial and Ground Rod System

RF, DC, AC power,

telecommunications,

data, and telemetry

services entering any

communications site.

Figure 3. Lightning current divides among the tower, cables and other conductive

surfaces, causing an inductive voltage-drop phenomenon.

If it is a minimum installation to meet

code, it may not be good enough. Ground

resistance testers are available to provide a

measurement value. For example, a residential

ground is acceptable at 20 ohms,

and 5 ohms is good enough to be considered

an adequate tower ground measurement.

But here’s where things become

uncertain. After the ground system is designed

using the four-stake Wenner

method resistivity measurement results,

performance after construction can be verified

by using the three-stake fall of potential

measurement (FOP).

There are two types of FOP ground

testers. The first is the traditional fall of

potential tester that uses three stakes

driven into the earth at measured intervals

and connected to the tester. A calibrated

AC current (100 – 300 Hz) is passed

among the stakes in various ways to facilitate

the measurement required. Ground resistance

is the meter reading when rod

three is at 0.618 the distance of rods one to

two, and the graph flattens. The returned

data is interpolated into value called ohm–

m or ohm-cm. Newer FOP meters can give

the results directly in ohms.

The second type is the clamp-on

ground tester that couples AC energy into

each ground rod or system of rods and radials

and calculates a reading directly in

ohms based on the timing and wave-shape

of the reflected energy. Although the fall

of potential measurement with driven rods

is considered more accurate, the clamp-on

device is easier to use and shows results

that come close to those of the FOP tester.

Figure 4. Multiple buried conductors (radials and rods), with attention to geometry

and materials, net a good reading on a ground resistance (impedance) tester and also

have an enhanced transient response.

Ground resistance

testing

How do you know if

the lightning ground is

good The first thing is

to find and inspect it.

Suspicious measurement

Most measuring devices use an AC source

current in the low-frequency range to calculate

the earth impedance of the grounding

component or system. The returned

measurement is the impedance in ohms at

Continued on page 12

11


specific frequencies between 100–300 Hz.

This is a useful measurement for an AC

power company or an electrician, but a

communications technician at a tower site

should regard these measurements with

suspicion.

Although lightning is a DC current

event, the fast change from no current to

peak current will cause a dv/dt voltage

drop across any conductor. Direct- and

magnetic field-coupled damage can be severe.

The strike event delivers energy into

a ground system that, unless properly designed

with a fast transient response, will

quickly saturate, causing a rapid rise in

GPR even though it might measure 5

ohms with a ground tester.

Consider the lightning grounding

system as an RF circuit. Ground rods have

a series inductance bridged by the earth’s

resistance. Connecting ground rods along

buried conductors (radials) presents a series

inductance bridged by earth resistance

with additional ground rods along the radial’s

length. The additional ground rods

can be considered in parallel, all bridged

by earth resistance. Multiple radials with

ground rods are all electrically in parallel

to further reduce inductance. Multiple

buried conductors as illustrated in Figure 4

(radials and rods), with attention to geometry

and materials, will net a good reading

on a ground resistance (impedance) tester

and will have an enhanced transient response

as well.

The best way to prevent lightningcaused

coaxial shield currents from reaching

equipment is to limit them from

entering the building. This may be accomplished

by installing, outside or inside the

building, a continuous panel bonded to the

ground system or a panel with one or more

large-surface conducting straps. The large

surface-area strap is necessary to provide a

low-inductance path to ground for the

entry panel’s DC surge

current, as well as provide

for the high-frequency

component of

the lightning strike energy.

Each coaxial line

as it enters the building

is attached to the

panel with a combination

protector and

feed-through device or

an additional ground

kit before connecting

to a protector.

A recommended

entry system (see Figure

5) would provide a continuous surface

area, single-point ground plate from the

coaxial cable entry to the ground system.

This continuous surface area ground plate

will:

- Keep inductance low

- Minimize inductive voltage drop

during a lightning strike

- Improve master ground bar (MGB)

performance

- Provide a low-impedance, single-point

ground by design, not installation

- Make provisions for grounding of all

RF protectors on the bulkhead, increasing

protector performance

- Accommodate installation of additional

surge protectors for DC, data, telephone

and telemetry lines with reference to the

same single-point ground

Figure 6. The voltage throughput of an RF

lightning protector without the ground lead

attached (bulkhead installation) is maintained

at about 26 volts peak to peak.

Scale: 10 volts per division.

Figure 5. A recommended entry system provides a continuous surface area, single-point

ground plate from the coaxial cable entry to the ground system.

The effectiveness of lightning and

surge suppression devices used to protect

wireless networks depends on a low-impedance

ground return path for conducting

surge currents and limiting differential

voltages. RF lightning protectors designed

to handle high surge currents with minimal

energy and voltage throughput to the

protected equipment should be used. Installed

on the bulkhead with no added

ground lead inductance, they reduce letthrough

voltages to the lowest industry

recognized benchmarks.

Grounding conductors can compromise

protector performance. The added inductance

through 1.5 feet of #1 AWG Cu

grounding wire adds about 675 volts to the

surge delivered to the protected equipment

by a lightning strike.

Figure 6 represents

the voltage

throughput of an

RF lightning protector

without the

ground lead attached

(bulkhead

installation). In

this case, the

voltage through-

Figure 7. The same protector represented

associated with Figure 6, but with 1.5 feet of

added grounding conductor, meaintains a

voltage throughput of about 700 volts peak

to peak. Scale: 200 volts per division.

12 PrimeConnection | 4 TH QUARTER 2012


put is maintained at about 26 volts peak to

peak. Figure 7 represents the same protector

performance with 1.5 feet of the previously

mentioned added grounding

conductor for a total throughput of about

700 volts peak to peak. The wave shape

used to compare both installation and protector

grounding methods was the IEEE 6-

kilovolt (1.2x50μs) open-circuit voltage

and 3-kiloampere (8x20μs) short-circuit

current.

A suitable RF bulkhead addresses

this concern through RF protectors installed

directly on the bulkhead without

the need for additional grounding jumpers.

Other services can be routed through the

bulkhead, grounded and protected, capitalizing

on the single-point ground.

A lightning-protection system for a

wireless communications site is a scientifically

based, common-sense integrated set

of the following concepts.

Grounding design measurements

The ground system design should be

based on targeted FOP impedance using

soil ohm-m resistivity measurements, the

depth and length of the radials, and the

length, diameter and number of rods, all

configured to the Institute of Electrical

and Electronics Engineers ground system

design characteristics. To ensure a fasttransient,

low-impedance earth ground response,

multiple rods and radials should

be chosen to reach the targeted FOP impedance.

The Times Microwave Systems Smart Panel entry system,

photographed at a convention display, offers the

recommended single-point ground plate.

Tower to entry port coaxial cable

Bend the conductor away from the tower

and toward the equipment shelter at the

lowest practical height above ground. Do

not connect the tower cable tray to the

entry port. Only active RF, DC, data and

tower lighting AC lines should complete

the tower-to-entry panel circuit.

Entry panel

Use the entry panel to provide a termination

for coaxial cable connectors and

lightning protectors, and for a low-inductance,

large-surface-area conductor to a

single-point ground connection. The entry

panel represents the last chance to reduce

damaging incoming currents from the

tower or coaxial cables.

Lightning protectors

Install lightning protectors on all circuits

subject to damaging currents. All protectors

should be bonded to the site’s singlepoint

ground.

The installation and grounding

methods for all surge protective devices

will determine their performance during

the lightning event and should be evaluated

at the system level as opposed to relying

on individual protector

manufacturer’s specifications.

Smart Panel Availability

Primus is a proud distributor of quality

products from Times Microwave, including

their Smart Panel entry system. For

pricing and availability, call Primus at

(800) 435-1636.

ANRITSU’S POPULAR

Site Master Handheld Cable

and Antenna Analyzer now

available at Primus for only

$6,099.00! While quantities last.

Must mention special when ordering.

for only


Surge & Safety Protection for Railway Communications

By Protection Technology Group

he deadline for transit

and freight operators

required to comply with

Positive Train Control

(PTC) is fast approaching. Several

new technologies are

available from The Protection

Technology Group to effectively

and reliably protect from

surges and thus contribute to

the PTC goal of preventing collisions,

derailments and consequently

injuries and casualties

to roadway workers as well as

costly disruptions to traffic

flow.

In the past, the rail and transit industry has mainly relied upon simple surge

protection technologies – spark gaps and gas tubes technologies, whereas PTC requires

a more advanced approach to surge protection for sensitive electronics.

Gas tubes and spark gaps degrade over time and have slow reaction time.

Transtector’s Silicone Avalanche Diode (SAD) based data and power protection is

not only fast acting, but the solid state characteristics also result in a non-degrading

surge protector.

PolyPhaser filter based RF protection also exhibits the

same fast acting non-degrading properties of the Transtector

devices. This makes the two brands a perfect fit for PTC applications.

PolyPhaser and Transtector offer protection solutions

SXRR

to meet your needs and AREMA standards. Besides the products listed below,

Transtector’s SXRR railroad crossing signal surge suppressor is a high-speed, highcurrent,

silicon diode surge protector and comes in both 90V and 120V. The SXRR

is designed specifically for PTC and meets AREMA standards.

For more information on these products, call Pat with Primus at (800) 435-1636.

PolyPhaser’s DGXZ Hybrid

RF protector is multistage,

multi-strike, fast

response, high current capacity,

+6Vdc pass coaxial lightning protector.

The DGXZ series provides surge

solutions to multiple rail applications such

as Class 1, transit, rail communication,

control center, bungalow and WIUs.

PolyPhaser’s VHF Series

offer DC block RF

lightning protection engineered

for high power

combined signals operating up to 750 W

between 100 MHz to 512 MHz. The

VHF series is band pass configured and

meets industry standards for the Narrowbanding

Initiative.

Transtector’s I2R series is

designed for indoor/outdoor

protection of sensitive

bungalow electronics

using flexible silicon or

MOV technology with

touch safe, surge rated fuses and visual/remote

status indication.

14 PrimeConnection | 4 TH QUARTER 2012


NewMar’s StartGuard TM Available at Primus

NewMar’s StartGuard Provides Voltage Protection During Engine Start

By NewMar

The abrupt DC system voltage drop that accompanies engine

starting can cause microprocessor-based voice and

data transmitters to “dump” programmed memory.

StartGuard solves this problem by providing supplemental

voltage to sensitive electronics while the engine is

cranked. It contains a sealed rechargeable battery which is

switched on-line to electronics when the starter switch or

solenoid is engaged. When the engine is running Start-

Guard automatically goes off-line and the internal battery

is recharged by the alternator.

DC INPUT

PROBLEMS HERE

VOLTAGE DIPS

CAUSED BY ENGINE

STARTING

NO PROBLEMS HERE

Specifications:

Input Voltage: 13.8 - 14.8 VDC nominal, 15.5 VDC max

Relay Activation Input Voltage: 7-15 VDC

Output: 20 amps max

Battery: 12 VDC, sealed rechargeable, 5-7 year life (typical) 5 amp-hour capacity, Certified by DOT and IATA for shipment by air

Back-up Capacity (Fully Charged): (See matrix)

Model

NS-12-20

Input

13.8-14.8 VDC Nominal,

15.5 VDC Max

Back-Up Capacity Dimensions Weight

1 Minute 2 Minutes Inches Centimeters Lbs Kg

H W D H W D

20 amps 18 amps

5.5 2.5

8.25 4.9 3.5 20.1 12.5 8.9

For more information on the StartGuard or any NewMar products, call Pat with Primus at (800) 435-1636.

15


4180 E Sand Ridge Rd.

Morris, IL 60450

LAST CHANCE!

This is your last chance to get this year’s

LIVE LEGENDARY

t-shirt before it’s no longer available!

To get your free Primus 2012 Live

Legendary shirt, call Shannon at

(800) 435-1636 or visit

www.primuselectronics.com. Next

year’s design will be unveiled in

February at NATE 2013.

“Just wanted to say thanks for honoring

us tower guys with your shirts. You make

us feel appreciated.”

-Customer, Walk-in

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