250W Professional FM Broadcast Transmitter



250W Professional FM Broadcast Transmitter. Overview

Suitability

This is a beautiful machine, recently upgraded to 250 watts for the 200 watt version we sold for over a decade. There are lot of these units going strong in the world working 24/7 without a hiccup. The internal 250 watt amplifier blocks will operate with ease at full power 24 hours a day non stop in any country and with any AC voltage in the world. The front panel has a neat little meter panel lit up in blue to indicate forward and reflected power.

Stereo with Audio Processing Option

This is the most popular version because it includes everything in one enclosure. The audio processing keeps the audio level 'LOUD', but not too loud whereby it causes over deviation and contravenes your permit. The trick is to get the sound as loud as possible so you can compete with the other stations on the dial, but at the same time keeping your signal legal. This is a tricky balance to maintain, but this version in stereo with our internal audio processers does exactly this. More Information HERE.



250W Professional FM Broadcast Transmitter. Front View

250W FM STEREO TRANSMITTER WITH AUDIO PROC (250wpllsl19p)
US$ 2033

250W FM STEREO 12V DC TRANSMITTER WITH AUDIO PROC (250wpllsl1912)
US$ 1991

250W FM COMPOSITE MPX INPUT TRANSMITTER (250wpll19p)
US$ 1687

FULLY PROGRAMMABLE REAL TIME DYNAMIC AND STATIC RDS (rds-upgrade)
US$ 174.90

RDS Option

As an optional extra this transmitter is available with dynamic and programable RDS fitted. If you want RDS option please (rds-upgrade) ADD TO CART

Antennas

250 Watts with a high performance well installed antenna is a typical set up for a local radio station for a big town or small city. In rural areas up to 45 miles range is possible.

    • SINGLE DIPOLE
    • 4.8dBi 2 DIPOLES
    • 7.8dBi 4 DIPOLES
    • 10.8dBi 8 DIPOLES
    • 4.8dBi 5/8 ANTENNA
    • -0.8dBi CIRC. DIPOLE
    • Folded Dipole

Our 500W EIRP package includes this transmitter complete with antennas and cables ready to go. It is a full system that complies with the regulations of the European Union and most other countries in the world.

5 Years! Warranty
5 YEARS
LIMITED WARRANTY
MORE INFORMATION


250W Professional FM Broadcast Transmitter. Rear View

VSWR Protection

The RF output power of the amplifier automatically folds back, very fast to a safe level when there is fault condition of poor SWR and return loss of any level for any duration of time. When the fault clears the amplifier restores to full power.

Temperature Protection

This unit is designed with high reliability in mind to work in hot countries close to the equator. The cooling system incorporates at the back three 60 mm fans and at the front one 80mm fan to keep the heatsinks in this unit cool to touch by hand. Many of these units are operational for years in Nigeria without any issues. If this is not enough, if any of the fans were to fail, and let's face it and be honest, that could happen after a few years of use, the internal temperature sensor will reduce the amplifier power down to a safe level to keep the temperature in check until the fan has been replaced by a new one.

250W Professional FM Broadcast Transmitter. MPX version

Construction

The enclosure is made in strong 16 gauge steel, powder coated and baked in satin black. This leaves a tough, durable surface that will never rot or corrode and be cleaned to shine for decades. The front panel is 19 inch across and 2U (3.5 inch) high with a depth of 12 inches, so it will fit with ease into a standard rack. It is very strong and difficult to damage even under extreme handling.

Settings

If you are qualified or understand broadcast radio specifications and parameters you can set the frequency and deviation yourself. This is easily done by flipping over the unit and adjusting the little dip switches on the underside panel. More information on this in the User Manual, you can find a link to this below.

Compliance

The stereo version with audio processing and limiting meets all the regulatory standards required out of the box and pre configured. In fact if you send us a copy of your permit and it's conditions, we will set it up exactly to the specification. This equipment complies with EU/CE harmonised standards and FCC technical requirements for FM broadcasting. More information HERE

User Manual

RF Specification

All stated measurements were made at 220VAC at 27 Deg. Celsius ambient temperature unless stated.

Power Output Adj. 1-250 Watts into 50 ohms
Spurious Emissions Less than -75 dB ref to carrier
Harmonic Emissions Less than -70 dB ref to carrier
Freq Stability +/- 1 KHz max. typ. +/-300 Hz
Deviation Sensitivity Stability +/-2 % max
Freq Fine Adj > +/- 1000 Hz
Freq Range 87.5 to 108 MHz in 100 KHz steps
Out of Lock RF Muting Less than -70 dB ref to carrier
Residual AM Less than 0.5 %
Synchronous AM Less than 0.5 %
RF Ruggedness Any VSWR phase or length of time
Output Connector N-Female
Operating Temp -20 to +40 Deg C

AF Specification

Pre-emphasis (50 uS/ 75 uS/ None) Selectable
Audio Input Connector Phono/ RCA type unbalanced sockets
Audio Input Sensitivity +4 dBu for +/- 75 KHz dev.

Version MPX Stereo and Audio Processor
Signal To Noise Ratio 80dB 65dB
Frequency Response 30Hz-76KHz 30Hz-15KHz
Audio Distortion 0.2% THD Max 0.2% THD Max (at MPX section)

AC Specification

Input Voltage 90-264 V AC 135-370 V DC 47-63 Hz
Input Power 500W for 250W RF OUT with RF SWR less than 1.5
Working Humidity 20-90% RH non-condensing
Safety Standards UL60950-1 TUV EN60950-1 BSMI CNS14336 CCC GB4943 J60950-1 approved
EMC Emission Compliance to EN55022 class B EN61000-3-2 3 FCC PART 15 / CISPR22 class B CNS13438 class B GB17625.1
EMC Immunity Compliance to EN61000-4-2 3 4 5 6 8 11 light industry level criteria A
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