Broadcast Transmitters

  • With David Kirk

Broadcast Transmitters

Contributing Editor David Kirk tunes in to the latest technology broadcasting to the airwaves...

This short overview looks at recent developments in terrestrial broadcast TV and radio transmitters over the past year. UHD has replaced HD as the preferred resolution for high budget television programme production but is only slowly being adopted as a transmission format except in the USA where ATSC 3.0 channels are gradually being introduced. A growing number of transmitter manufacturers are offering UHD-capable systems; others are relying on receiver manufacturers providing respectably good HD to UHD upconverters in their products. 

ABE Elettronica is introducing a new feature for its Wave series FM transmitters. Ranging from 30 W to 5 kW, these can now receive DAB/DAB+/HD radio through a built-in radio receiver and transmit the desired service in FM format. “This new function further enhances a transmitter with unique features, allowing for an additional option in case the main audio signal is missing and consequently reducing the probability of transmitting silence”, says ABE CEO Federico Forlani. Wave series transmitters incorporate a DDS modulator, plus a range of input interfaces with an automatic input switch. Each transmitter accepts moduless such as stereo/RDS coders, a Stereo Tool audio processor, a test tone generator, an audio monitor and analog/digital multiplex output. Among the input interfaces are analogue mono/stereo, two analogue MPX, AES/EBU, AES192, AES67, web radio receiver, FM/DAB/HD radio tuner, digital MPX over IP, ASI, Micro SD card, SAT/DTT receiver, and GPS. Each transmitter can integrate up to two satellite/terrestrial receivers. ABE's FM isofrequency implementation enables the transmitters to operate in single-frequency networks. Wave series units feature an integrated LCD display and keypad for local control. They can also be managed remotely through a web GUI, SNMP, and optionally via SMS through an integrated 3G/4G router.

Egatel offers a range of broadcast transmitters including recently introduced models using Asymmetrical Wideband Doherty technology with air cooling or liquid cooling to achieve efficiencies of up to 42% in COFDM. Egatel also produces a range of low power transmitters including UHF and VHF gapfillers in powers of 100 watts, 25 watts and 5 watts. These are available to work on all digital TV standards such as DVB-T / T2, ATSC 3.0 and ISDB-Tb.

Elenos’ Quick Block radio and television transmitters allow devices with transmission powers from a few kilowatts upwards to be combined from modules. DVB/T, DVB/T2, ATSC1, ATSC3, ISDB/T, ISDB/TB, DAB DRM, FM CDR and DTMB. Remote control is fully supported. 

GatesAir will introduce new FM and DAB Radio transmitters to international audiences at IBC. The Flexiva GX air-cooled FM solid-state transmitter family are designed to offer FM analog broadcasters an ultra-compact transmission platform. Introduced in 5 kW and 10 kW versions, the line now includes 50 W and 100 W models.

“Flexiva GX models are ideal for broadcasters seeking to refresh existing analog FM infrastructure with cost, space and energy-efficient systems,” says Senior Global Marketing Manager Keith Adams. “Large regional and national networks represent a key customer base. Using the latest high-efficiency, solid-state LDMOS technology, we have packed exceptional power density into a compact 5U chassis, providing broadcasters with powerful FM transmission solutions that deliver a remarkable overall efficiency rating up to 76 percent. The Flexiva GX Series also carries our solid-state design benefits forward, including modular, redundant transmitters with hot-swappable power supplies. The transmitters provide auto-switching inputs, with dual AES (including AES192), dual composite and analog left/right audio inputs. Flexiva GX transmitters support n+1 configurations, enabling large national network operators to build flexible and consolidated transmission sites that meet stringent uptime requirements.

Options include a GPS receiver to support SFN functionality, and our Intraplex IP Link 100e module for direct receipt of FM content instead.”

On the digital side, GatesAir’s latest MultiD Series DAB Radio transmitters are claimed to offer improved power and bandwidth management, connectivity, and monitoring and control functionality. Their chassis now supports up to four independent digital radio services across separate DAB/DAB+ channels, with selectable IP (EDI) and legacy (ETI) connections and versatile power output levels per channel. GatesAir’s original MultiD system integrates three separate transmitters within a single 1U chassis instead of requiring a separate transmitter for each channel plus an external combiner and auxiliary hardware. The new MultiD system design adds capacity for a fourth DAB service and removes the limitations of broadcasting all services within a single DAB channel band.

MultiD customers can now broadcast four independent DAB radio services across separate channels which is useful for broadcasters that were not allocated all licenses within a certain channel. Power output per channel can now be built to each customer’s specifications. For example, DAB broadcasters can now order a 1.5 kW MultiD system to support three 500 W services, or a 1.2 kW system to support four 300 W services. It is also possible to establish varied power levels across different DAB services. MultiD systems are now configurable to serve virtually any combination of power levels for up to four DAB services.

Hitachi-Comark recently introduced the EC600HP-BB3 VHF Band 3 E-Compact series high-efficiency, air-cooled solid-state DTV transmitters. The EC600HP-BB3 product line is available with up to four power amplifiers in parallel, producing from 1.15 kW up to 4.6 kW respectively. These output power levels are measured after the mask filter. The new VHF band 3 E-Compact delivers the same features as the UHF version including:

  • EXACT-V2 digital TV exciter licensed for ATSC 1.0, optional license for ATSC 3.0.     
  • Hot-swappable rectifiers accessible from the front panel of the PA chassis.     
  • Dual commercial off-the-shelf GE AC to DC rectifiers per PA in load share mode.     
  • Single drive exciter and controller or optional dual drive with auto switching.     
  • Newly improved system controller with a simpler graphic interface.     
  • Built-in surge protection devices to minimise power grid over voltage.     
  • Optional front panel touchscreen. 

The EC600HP-BB3 features the latest broadband Doherty LDMOS RF power amplifiers with efficiency of up to 40%. Each air-cooled power amplifier includes automatic cooling fan speed control that provides lower acoustic noise levels during operation while extending the life span of these fans.

Each 3 U PA features a rear-panel plug-in design for easy installation and maintenance. Multiple RF amplifiers are combined with an insulated RF combiner enabling Hot Swap of the PAs. Control and management through a web-GUI without need for any external software or drivers. SNMP for transmitter remote control and monitoring is also available. The E-Compact features the EXACT-V2

IP-optimised DTV exciters with DualCast technology and is easily upgraded from ATSC 1.0 to 3.0. EXACT-V2 delivers an ATSC compliant on-channel RF output and performs RF precorrection of both linear and non-linear distortion.

Jampro's JLPC antenna is a low power version of the company's Penetrator FM broadcast antenna. Both are designed for HD radio, stereo and SCA operation. Each JLPC bay consists of a Penetrator-style radiating element with a rigid shunt feed line supported by a galvanised steel mounting bracket. Standard round leg mounting brackets for a uniform face tower are included with each antenna. Silver plated inner conductor connectors are used throughout.

Plisch offers a range of transmitters including television and radio broadcast models for high power, medium power and low power applications. Supported standards include DAB(+)DMB, DVB-T/T2/lite, ATSC 1.0/3.0 and FM. Also available is the MON 5300 DAB+ monitoring receiver.

RFE Broadcast's Cosmic audio dynamics processor is now included as a standard feature in the company's FM transmitters. It can be configured with automatic modulation control, the average deviation value being kept constant within preset limits to avoid over-modulation peaks. Also incorporated is a four-position selectable filter profile (Bass Enhancer, Hi Lift, Crystal Voice and Club).

WorldCast Systems has introduced updates to its FM transmitter range, the Ecreso FM AiO series. Since the September 2022 launch of its 1 kW version, the Ecreso FM AiO has expanded to include 600 W, 300 W and 100 W powers. In addition to offline SD card backup, the Ecreso FM AiO series is now fitted with an online audio backup supporting IceCast and ShoutCast streaming. This means broadcasters can reuse an existing radio broadcast channel to achieve emergency continuity. They can play an audio file which is saved on the SD card, or they can recover an IceCast / ShoutCast stream and continue to broadcast the program live from a web radio source.