Generals. This FM amplifier is designed to operate on 87.5 - 108 MHz frequency range for FM radio broadcasting appliances.

The power amplifier. The FA 4000FS gives up to 4 kW of output power in continuous service. The amplifier cabinet has the spacing room compatible with the ITEL's exciters: the FT 30 LCD can be inserted plug-in to obtain the FT 2000FS LCD, the ITEL's FM Transmitter model with graphic LCD front panel to full control and measurements.

Lowest dimensions and weight in the market. A new coupling architecture permits a dramatic reductions of, dimensions, weight and cooling, simplifying transport, installation and maintenance.

COLD FET™ technology. This revolutionary technology, a ITEL's Elettronica international patent, is used in the FA 4000FS amplifier to optimize the input matching of MOS-FET transistors in order to obtain broadband amplification stages without any RF component. This means:
- high RF efficiency > 83%
- lower heating
- higher devices safety
- higher total reliability
- low AC power consumption

Extraordinary RF efficiency: the COLD-FET™ technology allows to obtain from the amplifiers the full power rating reducing of almost 20% the devices recommended operating DC voltage and current.

Uninterrupted service. A proportional foldback protection circuit reduces the output power without any on-air interruption, keeping the RF devices always within the safety conditions in case of:
- load mismatching
- environmental over-temperature
- cooling failure
- failure in one or more amplification modules
- failure in power supply modules

High modules redundancy: each 1 kW plug-in module is composed of 4 x 300 W stages coupled with high isolation combiners and independent power supply. This architecture assures the highest module redundancy.

High system redundancy: after the plug-in module redundancy starts the great system redundancy realized through the coupling system that permits to the amplifier to work at reduced power even in case of module failure.

On-air serviceable. The 1 kW modules replacement can be made without turning-off the amplifier.

High gain 18 dB gain permits the full output power with low input driving.

Broadband: no adjustments are required for the full power operation in the 87.5÷108 MHz band.

The automatic power control circuit adjusts and stabilizes with precision (±1%) the maximum output power in the whole band.

Switch-mode power supply. High efficiency (> 85 %) and oversized power supply modules grant low heating, low AC power consumption and superior reliability.

Low overheating. The high cooling system efficiency limits at only + 10°C the heatsink overheating respect to the environmental temperature. This permits the service even in overheated sites.

Low consumption. The high overall efficiency means a reduction of AC power consumption and operating costs.

Reduced maintenance. Easy accessibility of all parts, no RF failure, no power supply failure, external serviceable air filter reduce dramatically the maintenance costs.

Metering. A complete metering system placed on the front panel permits the precise reading of: all currents and voltages of each MOS-FET stage, forward power, reflected power.

Remote control. It is available as option a remote control interface for the following parameters: voltages and currents of each RF stage, forward power, reflected power, alarms status, on/off, stand-by.

RF specifications:
Operating frequency range 87.5 ÷ 108 MHz
Max. output power 0 - 4000 W
Input power 0 - 100 W
Input connector N
Output connector EIA 1+5/8" (others on request)
Power consumption (at maximum power) 5600 VA
Input and output impedance 50W
Spurious and harmonic suppression (ref. to carrier) < - 82 dBc
Synchronous AM (ref. 100% mod.) < - 50 dB
Asynchronous AM (ref. 100% mod.) < - 50 dB
RF Probe -50 dBc, 50W, BNC
Power stability < 1%
RF efficiency (before the output filters) 80% typ.
Overall efficiency 69% typ.

Measures (on the front panel):
Total output forward power
Total output reflected power
Output forward power of each 1 kW module.
Output reflected power each 1 kW module.
DC supply voltage of each 1 kW module.
DC supply current of each 1 kW module.

Protections:
The internal logic circuitry provides proportional fold-back protection, without on-air interruptions, for:
- VSWR
- air over-temperature or insufficient cooling
- output combiner unbalancing
- fault of RF or power supply stage

Automatic power control:
The automatic power control circuitry provides the output power regulation with a precision of 2% over the whole band.

Remote control interface:
I/O Connector DB-25

Monitored & controlled functions:
- stand-by
- Total forward output power
- Total reflected output power
- DC supply voltage of each 1 kW module.
- DC supply current of each 1 kW module.
- alarms status

AC Power requirements:
Type of DC voltage regulation switch-mode
Operating Voltage 110/220/240 Vac ± 10% 50/60 Hz, single-phase or 380/415 Vac ± 10% 50/60 Hz three-phase.

Operating conditions:
Cooling forced air by internal fans
Service Continuous 24/24 h
Operating temperature -5°÷ +45°C
Relative humidity 95%
Max.installation altitude 3000 m a.s.l.

Mechanicals:
Weight 245 kg
Dimensions (W x D x H) 540 x 1120 x 720mm - single rack