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
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•
•
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Company Overview
Sample Installations & Technological Issues
System Configurations
BE Solutions
Today’s Topics
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•
•
•
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
Big Pipe LT
• High bandwidth digital performance
• Upgrade you link for HD
compatibility at an affordable price
Audio Over IP
• No more worries about long,
unreliable paths
• Originate your signal with remote IP
access from your laptop
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
•
•
•
•
Company Overview
Sample Installations & Technological Issues
System Configurations
BE Solutions
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.
Interference Areas
Booster
Transmitter
Main Transmitter
Main 25kW FM
Transmitter
Synchronous FM
250W Booster
Terrain Shielded
Area
Tall Buildings –
Central Business
District
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
Interference
Zone
Zurich
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
0dB
-20dB
-40dB
-60dB
-80dB
-100dB
0 Hz
10 kHz
20 kHz
30 kHz
40 kHz
50 kHz
Two carriers – in phase
0dB
-20dB
-40dB
-60dB
-80dB
-100dB
0 Hz
10 kHz
20 kHz
30 kHz
40 kHz
50 kHz
Two carriers – ¼ dB deviation difference
0dB
-20dB
-40dB
-60dB
-80dB
-100dB
0 Hz
10 kHz
20 kHz
30 kHz
40 kHz
50 kHz
Two carriers – ½ dB deviation difference
0dB
-20dB
-40dB
-60dB
-80dB
-100dB
0 Hz
10 kHz
20 kHz
30 kHz
40 kHz
50 kHz
Two carriers – 1 dB deviation difference
0dB
-20dB
-40dB
-60dB
-80dB
-100dB
0 Hz
10 kHz
20 kHz
30 kHz
40 kHz
50 kHz
Two carriers – 90° time delay
0dB
-20dB
-40dB
-60dB
-80dB
-100dB
0 Hz
10 kHz
20 kHz
30 kHz
40 kHz
50 kHz
Two carriers – 180° time delay
0dB
-20dB
-40dB
-60dB
-80dB
-100dB
0 Hz
10 kHz
20 kHz
30 kHz
40 kHz
50 kHz
Today’s Topics
•
•
•
•
Company Overview
Sample Installations & Technological Issues
System Configurations
BE Solutions
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
STL Path
Uncompressed
AES/EBU STL
AES/EBU
Audio from
Studio or STL
GPS Receiver with 10MHz
TTL Level Output
AES/EBU Delay / Splitter
RF To
Transmitter
Uncompressed
AES/EBU STL
RF To
Transmitter
GPS Receiver with 10MHz
TTL Level Output
Fxi-60/250
Digital Exciter
Fxi-60/250
Digital Exciter
Transmission Site A
Transmission Site B
BE System Block Diagram
Using FXi ESP
STL Path
Uncompressed
AES/EBU STL
AES/EBU
Audio from
Studio or STL
GPS Receiver with 10MHz
TTL Level Output
AES/EBU Delay / Splitter
RF To
Transmitter
Uncompressed
AES/EBU STL
RF To
Transmitter
GPS Receiver with 10MHz
TTL Level Output
Fxi-60/250
Digital Exciter
Fxi-60/250
Digital Exciter
Transmission Site A
Transmission Site B
Today’s Topics
•
•
•
•
Company Overview
Sample Installations & Technological Issues
System Configurations
BE Solutions
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
Rich in Audio Inputs…
• 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
Balanced & Unbalanced
Composite Inputs
Dual Independent AES
Inputs
L&R Analog Inputs
..with Easy Source Setup
•
Primary/Backup Audio Source Setup
—
—
—
—
AES 1
AES 2
Composite
Analog L&R
AUDIO SETUP MENU
INT SCA
SETUP
BACK
ACTIVE AUDIO SOURCE
EX T SCA
SETUP
INT RDS/
RBDS SETUP
ACTIVE AUDIO SOURCE
COMPOSITE
SAMPLE RATE
44.1 kHz
PRIMARY AUDIO SOURCE
COMPOSITE
BACKUP AUDIO SOURCE
AES
COMPOSITE
D
AES SETUP
D
SETUP
COMPOSITE
SETUP
AUDIO INPUT SELECTIONS
EX T RDS/
RBDS SETUP
STEREO/
MONO SETUP
HELP
COMPOSITE
OUT SETUP
ANALOG L/R
SETUP
PRI/BACKUP
AUDIO SETUP
Dynamic RDS Generator
•
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
Input
External RDS
Generator 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 Time
SILENCE SENSE SETUP MENU
SWITCHBACK
TIME SET
MAIN
SILENCE SENSE STATUS ENABLED
PRIMARY THRESHOLD
BACKUP THRESHOLD
SWITCHOVER TIME
10 Sec
SWITCHBACKTIME
PRIMARY DELAY SELECTIONS
10 Sec
20%
20%
COMPOSITE
D
BACK
D
SETUP
SILENCE SENSE SETUP
SIL SENSE
ON/OFF
HELP
PRI
THRHD SET
BCKUP
THRHD SET
SWITCHOVER
TIME SET
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
IP SETUP MENU
UNI/BI
DIRECTIONAL
MAIN
GATEWAY
IP ADDRESS
10.2.4.105
SUBNET
255.255.255.255
10.2.2.21
COMPOSITE
D
BACK
D
SETUP
REMOTE INTERFACE IP MODULE
IP ADDRESS
10.2.4.105
SUBNET
255.255.255.255
GATEWAY
10.2.2.21
MODULE
SELECTION
EXGINE MODULE
IP ADDRESS
10.2.4.105
SUBNET
255.255.255.255
LINK TYPE
UNI-DIRECTIONAL
GATEWAY
10.2.2.21
MAC ADDRESS
EXPORTER MODULE
IP SETUP
00-03-F4-02-0E-02
SUBNET
SETUP
HELP
GATEWAY
XMTR
T-SERIES
SETUP
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
Things you may NOT need with the FXi 60/250esp….
Spectrum Analyzer
GPS Receiver
External Power Amplifiers
AES External Switching
External Stereo Generator
Standby Exciter
Backup Transmitter
$ 6,000- $20,000
$ 1,300
$ 3,500
$ 800
$ 2,000
$ 5,000- $15,000
$ 15,000
QUESTIONS?
Thank You
Tim Bealor, tbealor@bdcast.com
John Macdonald, jmacdona@bdcast.com
www.bdcast.com
Lutfi Aysan, aysan@onair.com.tr
System Timing
A= Transmitter Site A
B= Transmitter Site B
C= Interference Zone
D= Studio
D
A
AB+BC-AC = km of differential delay
20+3-17=6
6 x 3.34= 20 micro seconds of delay
C
B
AB= 20 km
AC= 17 km
BC= 3 km
DA= 7 km
DB= 24 km