250 Watt FM Broadcasting

Aareff 250wpllsl19p FM Broadcasting Transmitter

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Which Version Do You Need?

MPX. - This is the low cost version, but is not intended for the novice or beginners. The audio input is raw MPX without any audio limiting or stereo coder circuitry, this must be provided externally in accordance with the recommendations of:

Stereo Version. - This is identical to Mono/MPX version but with a stereo coder built in. RDS cannot be used with this. Again it does not include audio limiting, so it's not recommended for the novice or beginner. External limiting need to comply with the recommendations of:

Stereo and Audio Processing. - Most small radio stations and beginners will use this version, this is because it includes audio processing circuitry and suitable limiting to keep the transmitter in compliance with the maximum bandwidth permitted by the international regulations.

Five Years Warranty

Aareff FIVE YEARS !!! Warranty

We are so confident this amplifier won't let you down, it comes with a limited 5 YEARS!!! warranty
(see warranty conditions)

Do You Have A Question?

250 Watts up to 45 miles

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 posssible.


On the underside of this unit controls are accessible to set the:

All the versions of this transmitter will operate with a power supply of 90 to 260V AC.

250 Watt Amplification and Protection

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 of this transmitter has a neat little meter panel lit up with intense blue LED's to indicate forward and reflected power. The RF output power of the amplifier automatically folds back 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.


On delivery the equipment is ready to plug in and use with any suitable 50 ohm antenna system such as our Vertical 5/8 Wave, Single Dipole, 2 Way Stacked Dipole, 4 Way Stacked Dipole, 8 Way Stacked Dipole or Circular/Mixed antennas.

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.

Setting The Frequency

Instructions are supplied to show the station engineer how to set this system to any frequency between 87.5 and 108.0 MHz, this is easily done by reconfiguring the dip switches on the under side panel of the 1 watt driver exciter. However, when we test this system we have to set it to some frequency, we prefer it to be the one you choose, so please select from the box above the frequency you would like it set to on delivery.

RF Technical Specifications

Audio Input Sensitivity +4 dBu for +/- 75 KHz dev.
Freq Stability +/- 1 KHz max. typ. +/-300 Hz
Deviation Sensitivity Stability +/-2 % max
Freq Fine Adj > +/- 1000 Hz
Pre-emphasis (50 uS/ 75 uS/ None) Selectable
Audio Input Connector Phono/ RCA type unbalanced sockets
Power Output Adj. 20 to 250 Watt into 50 ohms
Freq Range 87.5 to 108 MHz in 100 KHz steps
Spurious Emissions Less than -75 dB ref to carrier
Harmonic Emissions Less than -70 dB ref to carrier
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 SO239 (or optional N type)
Operating Temp -20 to +40 Deg C

AF Technical Specifications

Version MPX StereoStereo and Audio Processor
Signal To Noise Ratio80dB 65dB 65dB
Frequency Response 30Hz-76KHz 30Hz-15KHz 30Hz-15KHz
Audio Distortion 0.2% THD Max0.2% THD Max 0.2% THD Max (at MPX section)
Stereo Pilot Tone None 19KHz +/-0.2Hz19KHz +/-0.2Hz

AC Technical Specification

Model RSP-320-24 x 2
Input Voltage 88 ~ 264VAC 124 ~ 370VDC 47-63 Hz
Power Factor PF more than 0.95/230VAC PF more than 0.98/115VAC at full load
Efficiency 87%
Input Power 500W max. 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 approved
EMC Emission Compliance to EN55022 (CISPR22) Class B, EN61000-3-2,-3
EMC Immunity Compliance to EN61000-4-2,3,4,5,6,8,11, EN55024, light industry level, criteria A


All these models comply with European standards ETS 300384 for R&TTE, EN 301 489-11 for EMC and (LVD) 2006/95/EC for safety, the relevant FCC sections of US 47 CFR Part 73 for verification and ITU-R BS.450-3 (11/01) FM Broadcasting at VHF.