fm synchronous boosters and single frequency networks tim bealor, vp rf products

FM Synchronous Boosters

And Single Frequency Networks

Tim Bealor, VP RF Products

John Macdonald, Sales Manager, Europe

Middle East, Africa

Lutfi Aysan, Onair Medya

Today’s Topics

• Company Overview• Sample Installations & Technological Issues• System Configurations• BE Solutions

Corporate Overview

Nearing fifty years of serving radio broadcasters worldwide

Headquartered in Quincy, Illinois

Products encompass program generation, audio and data management, inter-facility transport and analog and digital transmission

FM Transmitters

• Comprehensive product line from 50W to 70KW• All transmitters upgradeable to HD Radio

AM Transmitters

• Comprehensive product line from 500W to 100KW• All transmitters upgradeable to digital

Transport Products

Marti• The ONLY answer for traditional RPU

applications• Reliable, cost effective composite &

discreet STL’s

Digital Cellcast• Take your station anywhere!• The ultimate in remote portability

Audio Over IP• No more worries about long,

unreliable paths• Originate your signal with remote IP

access from your laptop

Big Pipe LT• High bandwidth digital performance• Upgrade you link for HD

compatibility at an affordable price

Studio Products

AudioVAULT• Broadcast delivery software system• Tools to manage, create and deliver

content• Personalized workspaces

The Radio Experience (TRE)• Complete message management

capabilities• Supports RDS, RT+, HD, Web

and more

SoniXtream•Turnkey internet streaming services•Branded custom players•Ad insertion •Multiple revenue generation

components

Today’s Topics


Synchronous FM Boosters:Why do we need them?

Scenario #1 – Filling in dead spots in coverage.– Allows the broadcaster to fix areas that are terrain shielded but would otherwise

be within the 1 mV/M (or other) contour.

Scenario #2 – Covering a long road with one station.– Increasingly, stations are getting licenses for a coverage along a major highway

with just a single frequency.

Scenario #3 – Regional coverage.– Allows a licensee to cover a region with several stations – all on the same

frequency

Fixing Dead Spots

Dead spots are created by terrain shielding – where there is no reasonable line of site.A low power, on frequency booster may be located within the shadowed area to improve coverage.

Main TransmitterInterference Areas

Booster Transmitter

Main 25kW FM Transmitter

Tall Buildings – Central Business

DistrictTerrain Shielded Area

Synchronous FM 250W Booster

Fixing Dead Spots

Creating continuous coverage on a road

Long, important highways are good targets for a radio station you can listen to without changing the dial.

Many small transmitters are synchronized to provide unbroken service.

Regional Coverage

True, regional stations may be created by synchronizing high power stations.

Station identity can be created – the frequency is the same across the whole region.

Frequency allocation is easier – the same frequency can be used for adjacent stations.

The Problem: Interference Zones

Where the coverage areas overlap, and the ratios of the signal strengths approach unity, the signal quality is affected.

Basel

Zurich

Interference Zone

Key Issues

•Where the coverage areas overlap, and the ratios of the signal strengths approach unity, the signal quality is affected. •If the RF carriers are not frequency synchronized, significant distortion and noise will result.•If the audio levels are not exactly the same, the noise floor increases dramatically with a “white noise” which varies with the level of the audio.•If the pilots are not synchronized, in both frequency and phase, the pilot detector in the receiver will switch back and forth and this will be audible in the stereo signal.•If the audio phase is not synchronized, distortion results.•If everything – audio, pilot & carrier are all synchronized, the signal will be optimized.

Composite Baseband: L=5kHz, R=7kHz

0 Hz 10 kHz 20 kHz 30 kHz 40 kHz 50 kHz

0dB

-20dB

-40dB

-60dB

-80dB

-100dB

Two carriers – in phase


0dB

-20dB

-40dB

-60dB

-80dB

-100dB

Two carriers – ¼ dB deviation difference


0dB

-20dB

-40dB

-60dB

-80dB

-100dB

Two carriers – ½ dB deviation difference


0dB

-20dB

-40dB

-60dB

-80dB

-100dB

Two carriers – 1 dB deviation difference


0dB

-20dB

-40dB

-60dB

-80dB

-100dB

Two carriers – 90° time delay


0dB

-20dB

-40dB

-60dB

-80dB

-100dB

Two carriers – 180° time delay


0dB

-20dB

-40dB

-60dB

-80dB

-100dB

Today’s Topics


Previous System Block Diagram

May be accomplished with GPS receivers at both sites, or by use of a reference tone to sync both exciters.

Problem: Doesn’t provide synchronized audio phase or level, or pilot phase.

What’s needed

(2) FXi-60 or FXi-250 Digital FM exciters

(1) Uncompressed Digital STL with AES/EBU input and output. We have used the Moseley Starlink 9400Q.

(2) Rack mounted GPS receivers with 10MHz TTL level output and outdoor antenna. We have used the ESE Model 110.

(1) AES/EBU Splitter/Delay with minimum delay time of approximately one microsecond, and increments of one microsecond to a maximum delay of one millisecond. We have used the Quantec Zombie 1212/DSP.

Other Company System Block Diagram

UncompressedAES/EBU STL


Fxi-60/250Digital Exciter


GPS Receiver with 10MHzTTL Level Output

AES/EBU Delay / Splitter

RF ToTransmitter

RF ToTransmitter


Transmission Site A Transmission Site B

AES/EBUAudio from

Studio or STL

STL Path

BE System Block DiagramUsing FXi ESP






AES/EBU Delay / Splitter

RF ToTransmitter

RF ToTransmitter


Transmission Site A Transmission Site B

AES/EBUAudio from

Studio or STL

STL Path

Today’s Topics


BE’s approach - Synchronize everything

•The entire system is digital. •The audio is synchronized by using an uncompressed Digital AES/EBU Link• The levels of the transmitted audio are locked because we use the AES/EBU inputs on the FXi ESP series exciter.•The carriers and the pilot are synchronized by using the internal GPS receiver. •The delays are extremely accurate because of 1usec internal delay accuracy•A patent has been applied for.

This is what makes it happen

FXi 60/250esp• Adaptive pre-correction• Internal delay• Internal GPS receiver• IP connectivity • Dual RF outputs• Direct to carrier synthesis

And Much Much More

No External GPS Required

• Internal GPS Receiver with rear panel antenna connection• Self Contained Synchronous Booster Operation

— Locked to GPS, 10MHz and 1PPS

— Pilot and Carrier locked to 1PPS

• 1usec delay resolution designed to specifically accommodate booster operation

Timing Inputs

Ideal for Analog and HD Simulcast

• Only BE provides delay of composite input• Delay AES Inputs• 1usec delay resolution• 0 to 15 seconds delay of FM Analog for Diversity Delay• User defined Ramp Up and Ramp Down Time

0.1dB Deviation Accuracy

• If the modulation levels from two different exciters in a booster application are not exactly the same, it will result in the audio having a significant amount of noise and distortion.

• When implementing a synchronous or single frequency network the AES audio input should be used.

• This allows the FXi esp exciter to set the modulation levels to 0.1dB accuracy.

• Level differences of 0.3 to 0.5dB can result in poor audio quality near the overlap areas.

System Synchronization

• Signal Outputs for external use— 10MHz

— 1PPS

— 19kHz Pilot

• Internal GPS eliminates need for additional GPS receiver

Timing Outputs

True Dual Exciter Operation

• Dual RF Outputs allow one exciter to drive TWO transmitters!

• High Power (0 to 250 watts)• Medium Power (0 to 15 watts)• Higher output power levels eliminate the need for

additional external amplifiers

High Power RF Output

Medium Power RF Output

• More than any competing brand!

• Audio Inputs— Dual Independent AES/EBU Inputs eliminate the need for

external AES switching

— L & R Analog Inputs

— Balanced & Unbalanced Composite Inputs

Rich in Audio Inputs…

Dual Independent AES Inputs

L&R Analog Inputs

Balanced & Unbalanced Composite Inputs

..with Easy Source Setup

• Primary/Backup Audio Source Setup— AES 1— AES 2— Composite— Analog L&R

AUDIO SETUP MENUBACK

DCOMPOSITESETUPD

COMPOSITESETUP

COMPOSITE OUT SETUP

ANALOG L/R SETUP

PRI/BACKUPAUDIO SETUP

INT SCA SETUP

EXT SCA SETUP

INT RDS/RBDS SETUP

EXT RDS/RBDS SETUP

STEREO/MONO SETUP

AES SETUPACTIVE AUDIO SOURCE

ACTIVE AUDIO SOURCE

SAMPLE RATE

HELP

COMPOSITE

PRIMARY AUDIO SOURCE COMPOSITE

BACKUP AUDIO SOURCE AES

AUDIO INPUT SELECTIONS

44.1 kHz

• Truly expands your RDS message capabilities! —Accepts dynamic serial RDS data or external generator—Eliminates need for external RDS generator—Serial data from source

Dynamic RDS Generator

External RDS Generator Input

Dynamic RDS Input

Flexible I/O Configuration

• Allows flexible operational control for specialized installations• More than 45 unique settings• User-Defined General Purpose I/O

— Can be used with any remote interface— 12 inputs with 12 outputs

• All I/O’s are mode selectable

Defined GPI/O

User-Defined GPI/O

“True” Silence Sense Detection

• No dead air in your revenue stream• User adjustable parameters-You’re in Control!

— Threshold Level

— Switchover Time

— Switchback TimeMAIN

DCOMPOSITESETUPD

SIL SENSEON/OFF

PRI THRHD SET

BCKUP THRHD SET

SWITCHOVERTIME SET

SWITCHBACKTIME SET

BACK

PRIMARY DELAY SELECTIONS

SILENCE SENSE SETUP MENU

SILENCE SENSE SETUP

SILENCE SENSE STATUS SWITCHOVER TIME

SWITCHBACKTIMEPRIMARY THRESHOLD

BACKUP THRESHOLD

HELP

ENABLED

20%

20%

10 Sec

10 Sec

Upgrades Station Measurement Capability

• Instrument Grade Spectrum Analyzer eliminates the need for an external unit

• Capable of measuring NRSC mask compliance• High resolution spectrum display of all modes

— -20 dB ratio FM+HD— -10 dB ratio FM+HD— FM Only— HD Only

Ethernet Connectivity

• IP Addressability for Remote Access• Easy set up

MAIN

DCOMPOSITESETUPD

MODULE SELECTION

IP SETUP

SUBNET SETUP

XMTRT-SERIESGATEWAY

SETUP

UNI/BIDIRECTIONAL

BACK

IP SETUP MENU

REMOTE INTERFACE IP MODULE

IP ADDRESS

SUBNET

GATEWAY

EXGINE MODULE

IP ADDRESS

SUBNET

GATEWAY

HELP

10.2.4.105

255.255.255.255

10.2.2.21

10.2.4.105

255.255.255.255

10.2.2.21

EXPORTER MODULE

IP ADDRESS

SUBNET

GATEWAY10.2.4.105

255.255.255.255

10.2.2.21

LINK TYPE UNI-DIRECTIONAL

MAC ADDRESS 00-03-F4-02-0E-02

Reduced Downtime in Backup Operation

• 8 Independent, selectable and downloadable configurations— Mode of Operation

— Frequency

— Output Power

— Audio Source

• N+1 Applications• Backup Transmitter Applications

Reduces AES Conversion Cost

• Provides Composite output to drive main analog or backup transmitter

• Eliminates the need to upgrade an analog only transmitter to accept AES input

• Eliminates need for external stereo generator

Composite Output

Efficient Operation and Troubleshooting

• Front Panel Diagnostics and Metering— Larger Front Panel Display

• 8.4” display— Soft-Key Menu Selection— 18 analog parameters

• Forward Power• Reflected Power• Power Supply Voltages

— Alarm Indication• Latched Output

— Fault Indication• Non Latched

— Event Logging

Lower Cost of Ownership

Spectrum Analyzer

GPS Receiver

External Power Amplifiers

AES External Switching

External Stereo Generator

Standby Exciter

Backup Transmitter

$ 6,000- $20,000

Things you may NOT need with the FXi 60/250esp….

$ 1,300$ 3,500

$ 800

$ 2,000

$ 5,000- $15,000$ 15,000

QUESTIONS?

Thank You

Tim Bealor, [email protected]

John Macdonald, [email protected] www.bdcast.com

Lutfi Aysan, [email protected]

System Timing

ABC

D

A= Transmitter Site AB= Transmitter Site BC= Interference ZoneD= Studio

AB= 20 kmAC= 17 kmBC= 3 kmDA= 7 kmDB= 24 km

AB+BC-AC = km of differential delay20+3-17=66 x 3.34= 20 micro seconds of delay

fm synchronous boosters and single frequency networks tim bealor, vp rf products

Documents

coverage areas

regional stations

radio station

frequency booster

frequency allocation

adjacent stations

high power stations

areasynchronous fm