A Handy Road Map for Your NAB Show Transmitter Trek

The spring NAB Show in Las Vegas provides the best opportunity to get an up close look at all the high-dollar capital items you may need in the upcoming year. April 17, 2017

The  spring NAB Show in Las Vegas provides the best opportunity to get an up close look at all the high-dollar capital items you may need in the upcoming year.

In our March issue, we covered audio-over-Internet Protocol consoles and router systems; this month, we’re looking at the latest in transmitter technology — the big players, of course, and some you may not have heard of before, all deserving of your attention.

There are multiple reasons to look at transmitters, including:

● Replacement of an old, tired main transmitter
● Addition of a backup transmitter
● Addition of an alternate transmitter site (perhaps with an N+1 methodology)
● Construction of an LPFM
● Construction of a translator site

As I cover various brands, I’ll point out which transmitters could fit into each of those categories, just to give you some ideas to get your search started.

Let’s head out to the floor!


Armstrong FMX 300

Along with their line of AM transmitters, Armstrong (located in booth N8416) offers some FM transmitters.

The T series, which is a single tube, grounded-grid design, comes in power levels up to 35 kW. Armstrong’s line of solid-state transmitters includes the FM-2500B, the FM series B (up to 12.5 kW) and the series C (up to 6.5 kW).

If you need a high-power exciter, or perhaps an LPFM transmitter, consider that Armstrong also offers a line of exciters, one of which is the FMX-300B. As its name suggests, it tops out at 300 W and features front panel frequency-agility, an LCD display of all parameters and full remote control and status indicators.

Automatic power output control and VSWR protection are useful features, if you plan to feed an antenna directly; an optional FSK IDer and an optional stereo generator make it a candidate for a translator, as well.


If you’re searching for a new AM transmitter, consider Broadcast Electronics (booth N7512).

BE makes two lines of AM transmitters: The A series (500 W to 10 kW) and the E series, at 2.5 or 5 kW. Features common to the A and E lines are high efficiency, low acoustical noise generation and cool running temperatures. Power amplifier modules are accessible from the front panel. Either line is adaptable to HD or DRM.

BE offers FM transmitters in six power ranges: The single-tube transmitter line is the T-series with a range of 20 to 40 kW; the S-series offers a completely solid-state solution in the 4 to 20 kW range; the solid-state C-series range is from 500 W to 5 kW; the STX-LP series range from 1 to 5 kW; and the STXe from 5 W up to 500 W.

The STX-HP series includes the STX-10, BE’s newest solid-state FM transmitter, requiring 22RU of vertical space in a standard rack (30 inches deep).

STX 10 makes use of hot-pluggable power amplifier modules and power supply modules, and achieves 70 percent AC-to-RF efficiency. The STX 10 can be accessed from any PC, tablet or smartphone, and is also SNMP V2 and V3 compatible.

Last year, Broadcast Electronics announced the release of a direct connection interface with the Davicom remote controls, making use of the built-in SNMP agent in the STX 10, and the SNMP manager in Davicom’s DV-mini and the DV-208/216 remote controls.

STX 10 can also be used in an N+1 system, or in a single frequency network, due to a delay feature in the exciter. If you are planning to transmit HD Radio, you would then equip the STX 10 with a STXe 500 exciter.


BW Broadcast TR600V2

BW Broadcast (booth N8631) offers up several “one-box” solutions for translators.

Their TR600 V2 combines the technology from the RBRX1 re-broadcast receiver and the V2 transmitter. The built-in receiver has audio and RF bandwidths configurable to meet “the most demanding applications.” The receiver can handle strong signals at the local transmitter site while still picking up distant broadcast signal to be retransmitted. “Plan-B” silence detection automatically switches to either of the MPX, analog or AES/EBU inputs, to keep going just in case it does lose the distant station. Built-in audio processing eliminates the need for a separate audio processor.

Regarding the transmitter portion, the TR600 V2 features “slide-in” power supplies that can be replaced quickly, should one fail. It can supply between 60 to 610 Watts of RF output power, with VSWR and temp monitoring.

It also features extensive remote control: You can access it via Ethernet (LAN or internet) and SNMP. It has configurable status and alarm ports that can control external equipment. Alarm messages are logged and can be sent out as email alerts.

As a translator, it has a built in Morse code FSK ID keyer as standard equipment, and RDS PI code checking to prevent the translator from being hijacked or jammed.


Continental 816R in red livery

Continental Electronics (booth N7520) continues to offer the 816R line of FM transmitters and the 816-HD and 816-HDR lines (HDR meaning “HD-ready”).

The 816R line covers the power range of 11 to 40 kW, using the same three-bay design for the last 30 years, with the 4CX15000A, the 4CX20000E or the 4CX25000C (depending upon power level, of course) driven by the solid-state IPA.

The 816HD family of transmitters is based on three different analog FM+HD power levels: the 816HD-20 for power up to 20 kW; the 816HD-25 up to 25 kW of power, and finally, the liquid-cooled 816HD-28L for applications up to 30 kW of analog power.

Common features of the Continental line of FM transmitters are the single-tube design; solid-state IPA; SCR “Soft-Start;” automatic power output control; use of the quarter-wave cavity in the output amplifier; use of the grounded screen grid circuit using screen neutralization; automatic filament voltage regulation; automatic power interrupt recycle; two independent VSWR protection circuits; and, a positive-pressure cabinet, which helps to keep the inside of the transmitter clean.


Crown FME series

The Crown Broadcast (booth N6927) E series deserves a look if you need a high-power solution for a relatively small space.

The E series (FME 3000, 4000, and 500) transmitters all make use of FME100 exciter, which uses direct-to-channel modulation and a built-in stereo generator with both analog and digital inputs and automatic fail-over. A dynamic RDS encoder is included as well.

FME 3000 consists of the exciter and two FME1500 amplifiers combined; the FME 4000 has two FME2000 amplifiers combined; the FME 5000 uses three FME 2000 amplifiers combined. Other common features are remote access via Ethernet; SNMP support; GPIOs for local connections to a remote control; and relatively small size (the FME 5000 needs at least 14 RUs, not including space above or below for air flow).


Ecreso (part of WorldCast Systems, booth N8924) has an extensive line of solid-state FM transmitters, from power levels as low as 100 W, to as high as 10 kW.

Ecreso 10 kW

The Ecreso 10 kW all solid-state transmitter features hot-swappable power amplifiers, power supplies, and fans; its exciter uses direct-to-channel digital modulation, and is ready for “digital MPX” (also known as MPX over AES/192 KHz SR). The exciter can supply audio from a micro SD card, via its silence detection and auto-switchover; it comes with an integrated FM limiter and AGC, clipper, MPX power control and a built-in dynamic RDS encoder.

The transmitter provides full TCP/IP and SNMP support for remote control, GPIOs for local control, as well as their Advanced Measurement Interface and Expert Maintenance Reporting.

AMI allows the end-user to see a real time dashboard that provides an at-a-glance overview of the transmitter performance. Built-in instrumentation enables detailed analysis of the RF Spectrum, baseband spectrum, audio spectrum and peak meters, all displayed simultaneously.

EMR is a proactive service that sends regular reports on the status of key parameters — such as temperatures, currents and voltages, plus information on the performance and lifespan of components (such as the fan and power supply of the transmitter). The system works through a data cloud managed by WorldCast Systems.


GatesAir Flexiva DAX

The GatesAir area at the show (booth N2613) is one for which you should dedicate part of a day, if you’re in the market for a transmitter. Whether you’re looking for an AM transmitter, an FM transmitter or a digital radio transmitter (HD, DAB or DRM), make sure you plan your trip accordingly.

For AM, GatesAir offers the 3DX series (25, 50 and 100 kW levels); the DX series (10 and 15 kW levels) and the Flexiva DAX series (1–6 kW).

Their FM line is more extensive and includes the Flexiva Compact and the Flexiva High Power, among others.

Let’s take a look at those two lines.

The Flexiva Compact comes many different power levels — the lowest of which makes an exciter, and the highest of which
a medium power transmitter. Its main features are:

GatesAir Flexiva HPX

● Power levels up to 3850 W (analog FM), 3100 W (FM+HD Radio)
● Broadband, frequency agile design 87.5–108 MHz, requiring no tuning or adjustments
● 2, 3 or 4RU design
● Direct-to-carrier digital modulator with
● Integrated stereo encoder
● ITU-R BS412 peak program/multiplex power limiter
● Static RDS generator
● Two AES, one analog L/R and two composite program inputs with automatic failover switching
● Digital MPX/Composite input over AES192 interface with fail-over switching
● Operation over a wide range of voltage and power stability conditions
● Full remote control capability including web-based HTML GUI interface, SNMP support, parallel control/monitoring and extensive fault, warning and operational parameter logging

Optional features:

GatesAir Flexiva FAX compact FM

● GPS receiver for SFN synchronization
● Orban Optimod 5500H multi-band audio processor
● Gen 4 HD Radio Exgine modulator card

If you are in need of more power, consider the Flexiva High Power line. Its main features include:

● Identical power blocks for scalability, power level 5,000–80,000 Watts 5 kW or 10 kW power blocks in only 16 rack units
● Common dual 1800 Watt Power Amplifier and IPA modules for all power levels
● Single-phase or three-phase power, Delta or Wye configurations; 190 to 464 VAC
● 1:1 Power supply to Power Amplifier module
● Hot-pluggable, hot-swappable power amplifier and power supply modules
● Distributed hardware-based control architecture uses analog circuits to control critical transmitter functions — not reliant on a microprocessor
● Hardware-based life-support backup controller
● Can use any standard FM exciter or can be tightly integrated with FAX low power exciter


Nautel NX25

At booth N8234, Nautel offers both AM, FM and digital radio transmitters (HD and DRM). NX is their AM line, and goes from 3000 W up to 50 kW. (The J1000 is availabe for 1000 W applications.)

Introduced at least year’s spring show were the NX3 and NX15 (3 and 15 kW power levels, respectively). Some of the NX line’s design features include RF amps that are hot-pluggable from the front of the transmitter, having only four transistors that can be replaced using only a screwdriver; a very high degree of linearity achieved by the employment of six-phase, direct digital modulation encoded at 2.7 mega-samples per second; and, pre-correction for all primary forms of distortion which typically affect both analog and digital AM broadcasting, including envelope equalization, AM-AM correction, and AM-PM correction.

All NX Series transmitters include Nautel’s Advanced User Interface with Ethernet access. Some of the features of the AUI include:

● Real-time impedance locus measurement
● Instrument grade spectrum analyzer
● IBOC modulation analyzer
● Module level monitoring and control
● Logging of all functions
● 100-percent remote access

Nautel’s line of FM transmitters includes VS (300 W to 2.5 kW); the NV-LT (3.5 tp 40 kW); and the GV line (3.5 to 88 kW).

Let’s examine that in detail.

Nautel GV40

The GV Series incorporates solid-state components in highly redundant, hot-swap architecture (power amp modules feature screwdriver-replaceable high-power FETS). Common modules across the GV family minimize spares requirements. GV comes with an integrated exciter.

Local control is provided by means of the front-panel touch screen (and GPIOs for connections to a remote control) and Nautel’s AUI, so that the same level of control is accessible via IP from anywhere. GV Series transmitters also provide an additional LCD display on the control module for extra control redundancy.

The GV will operate as a combined amplifier should the station wish to transmit HD radio. It supports adaptive pre-correction, MPX over AES and accepts I&Q directly to permit a plug-in HD Radio Exgine card.

Some of GVs other features include:

● HD spectrum/efficiency optimizer
● Separate controller “back up” user interface
● Low mains operation down to 90 V (at 1/3 TPO)
● Dynamic RDS scrolling
● Asymmetrical sideband capability
● MPX over AES
● Nautel’s instrumentation in the AUI includes:
● oscilloscope instrumentation
● MER instrumentation
● Spectrum analyzer (RF out or MPX baseband)
● Constellation view


Nicom NT-2000

One transmitter manufacture you may not be familiar with is NicomUSA (booth N7227).

Let’s have a look at their NT-2000.

As the name suggests, its output power is adjustable, from 5 W up to 2000 W with APC and the unit includes low pass/harmonic filter, so that it can be used as a stand-alone transmitter. The output connector is a 7/16 DIN Female. AC power requirement: 220-240 VAC, 50-60 Hz, single phase. Overall power consumption is approximately 3500 W.

Its exciter portion features front-panel frequency agility in 10 kHz increments. (All front-panel functions are password protected.) It has four unbalanced inputs: one for MPX and three for SCAs. The design features direct-to-carrier frequency modulation.

The NT-2000 includes remote control for power on/off, forward and reflected power metering and internal temperature. The company says that its frequency can be changed by remote control, which potentially makes it usable in a N+1 system at a backup transmitter site.


At the N7729 booth, you will find transmitter manufacturer OMB. They offer a line of solid-state FM transmitters from 500 Watts up to the 5000 Watt level.

If you are looking for a low power transmitter as backup, or perhaps as an LPFM transmitter, then you could consider the EM 500 HE. Using a MOSFET-based RF power amplifier, it tops out at 600 W, with a typical RF efficiency of 82 percent. The speed of its cooling fans is optimized, in consideration of the power amp temperature, to minimize acoustical noise. It features advanced protection against high-VSWR conditions and includes a low-pass filter (attenuating harmonics in excess of 80 dB).

One option is a built-in stereo generator with an AES input and automatic source switching. GPIOs are provided for local control, which can also be accomplished via RS-232 and local computer.

The unit also features event logging.


At booth N7216, PTEK shows the FM300ES, which is type-certified for LPFM use and can be used as a standalone transmitter or translator.

All ES models have a front panel programmable FSK ID. Some of its other features include a built-in stereo generator; a remote control interface; AC power input range from 88 to 264 VAC; frequency agility; proportional (VSWR) fold back; and, front panel metering. It uses a type-N female connector for the RF output.

The ES line includes the FM500ES and the FM1050ES in addition to the FM300ES. PTEK also offers the Gamma series, which goes from the Gamma2000HE up to the Gamma5000HE.


Rohde and Schwarz THR9 Liquid-cooled FM transmitter

Rohde & Schwarz (booth SL1205) is a transmitter manufacturer with which many of you are probably not familiar — although it’s one of the largest in the world.

Their THR9 high-power FM transmitter line is liquid-cooled and can deliver FM output of up to 40 kW in one rack, and 80 kW in two racks. One PHR901 power amp can supply up to 5 kW of FM, or alternatively, 3 kW of FM with -10 dBC of HD; two PHR901 amps can supply double that (as one would expect).

The THR9 transmitter family for band II attains overall efficiency values of up to 75 percent in analog FM mode; they incorporate redundant transmitter cooling systems; and as mentioned above, they support the hybrid HD Radio standard (IBOC), as well as purely digital standards in Band II (87.5 to 108.0 MHz).


Bext XL10000

Bext (a company that is a not exhibiting at the NAB Show) has an extensive transmitter line and the XL 10000 is one you may want to investigate, if you were considering an N+1 solution for an alternate transmitter site project.

The XL 10000 is solid-state, frequency-agile, 10 kW transmitter with user-adjustable output levels, proportional fold-back in the event of excessive VSWR and automatic power control. It also has a built-in low pass/harmonic filter that meets or exceeds all FCC and CCIR requirements; the output connector is a 1 5/8 EIA flange. Its built-in exciter can be fed by an optional AES input module or by an optional stereo generator module. Its AC Power Requirement is 208-240 VAC, single or three-phase (which you specify when ordering).

The user can access all settings and readings from the front panel or via Ethernet (allowing LAN or internet access). Its remote control is accessible via Ethernet as well, as is its operating frequency.

The user manual and other technical documentation are available via a USB port in the front panel.

The XL 10000 is 21.5 inches wide and 33.5 inches tall and 31.5 inches deep, so it will even fit in to a relatively small space.


Elenos E10000 web interface

Elenos — a company that is not exhibiting its products on the show floor but will have a presence in Las Vegas — offers the E10000 Extreme, a 10 kW amplifier needing only 4 RU of height.

The unit contains 14 amplifiers each capable of developing 1 kW, and three power supplies, each capable of supplying up to 5 kW of DC power. It features dual speed VSWR protection: fold back in the case of slowly increasing reflected power, and instantaneous in the case of a fast increase.

It also features high temperature protection — the proportional reduction of RF power to keep the temperature at an acceptable value. (Temperature is measured on each MOSFET and on each power supply.)

The E10000 features advanced diagnostics, including measurements of the voltage and current of power supplies, RF efficiency, power consumption, the temperature of each MOSFET, the temperature of each power supply, the fan speeds, temperature of the input air flow, temperature of the output air flow, and last but certainly not least, forward and reflected power and the input drive power.

Elenos also offers a compact line of FM transmitters that they’ve named the Indium series, comprising the ETG 2500, the ETG 3500 and the ETG 5000. These transmitters include a built-in exciter with built-in stereo generator with analog and AES inputs (24-bit, 32 through 96 kbps sample rate, with automatic fail-over the analog).

Ultimately, the NAB Show isn’t just about sitting down to enjoy dinner or a beer with business associates and friends — although that certainly adds to the fun.

Once per year, the Las Vegas Convention Center becomes the nexus of everything broadcasting, and the NAB Show provides a great opportunity to get your hands on the cool gear you’ve only been able to read about before.

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