XL 50 – New Generation 50 W Full Featured FM Transmitters
● NEW Now available with optional built-in multiband high performance Audio Processor
● Easy access to settings, functions and readings via touch screen color display and via web page
● Built-in User Manual file always accessible via front panel port even when AC power is disconnected
● Options include AES-EBU Digital Audio Input, Dynamic RDS/RBDS Encoder, Audio Over IP, SNMP2
● Newest high efficiency, high ruggedness LD MOS devices capable of withstanding 65:1 VSWR
● Conservatively rated, easily replaceable, highly efficient power supplies
● Proportional Auto-Foldback of RF output power protection in the event of excessive VSWR
● Excellent audio performance and built-in Stereo Generator with fast acting audio limiter
● Up to six available user-programmable profile presets for use as a backup of multiple FM stations
● Programmable FSK ID Keyer by software for use as auto-ID of Translators or Boosters
● Optional 10 MHz Ext Ref port + 1 pps port for Phase Locking & Time Delay Adj. to sync boosters or SFNs
● Highly efficient transmitters with low power consumption and low heat generation
● All Bext FM transmitters include low pass/harmonic filter and meet or exceed all FCC requirements
● RF Specifications
Nominal RF Output Power: 55 W (XL50), 160 W (XL150), 330 W (XL300), adjustable from menu or via webpage
Power control stability: Better than 0.1 dB
RF Output: N Type female connector,
50 W impedance, unbalanced.
Frequency range: 87.5-108 MHz, front panel programmable or via webpage, 10 kHz steps
Reference: 10 MHz TCXO
Off-lock attenuation: > 80 dBc
Start-up time: Typically 5-10 seconds
Type of modulation:
F3E / F8E direct FM at carrier frequency
Frequency deviation: Nominal ±75 kHz,
Accuracy of deviation:
< ± 2 dB from 87.6 to 107.9 MHz
Frequency drift: £ 1 kHz/year MAX (due to internal TCXO aging).
Short term stability: ± 1 ppm from -5 to +45 °C (100 Hz @ 100 MHz)
RF Harmonics:
Exceeds EBU/CCIR/FCC requirements
RF Spurious:
Exceeds EBU/ CCIR/FCC requirements
● Audio General Specs
Preemphasis: Selectable Flat / 50 / 75 micros.
Preemphasis Precision: Better than ± 0.5 dB
Wideband Amplitude Response:
± 0.2 dB 30 Hz to 100 kHz
Wideband AM Asynchronous: (FM = no modulation, Ref = 100 % AM, Unweighted, RMS detector, BW 30-100 kHz) < -68dB, typ. -80dB
Wideband Distortion, THD: < 0.1% (typ. 0.05%)
WB Distortion, IMD: < 0.1% (typ. 0.05%)
WB Transient IMD:< 0.25% (square/sine wave)
● Composite & Mono Specs
S/N: Typical Values referred to ± 75 kHz:
Weighted (CCIR 468/2 – Peak CCIR detector) – 75 dB / 50 ms – 69 dB / flat;
Weighted (CCIR 468/2 – RMS detector) – 79 dB / 50 ms -72 dB / flat;
Unweighted (RMS detector, meas. 20 Hz-23 kHz) – 86 dB / 50 ms – 80 dB / flat (stereo);
Unweighted (RMS detector, meas. 20 Hz-23 kHz) – 92 dB / 50 µs – 88 dB / flat (mono)
IMD: 70 Hz / 6 kHz 4:1 RATIO < 0.03% measured with 1 kHz and 1.3 kHz tones, 1:1 ratio @ 75 kHz deviation
Transient IM: < 0.03 % (square/sine)
Audio response: ± 0.15 dB 20 Hz to 15 kHz
AM Synchronous: (AM = 400 Hz, FM = 400 Hz ± 75 kHz Ref. = 100 % AM , RMS detector, meas. 20 Hz-23 kHz ) < -69 dB
AM Asynchronous: FM = no modulation, Ref. = 100 % AM, Unweighted, RMS detector, meas. 20Hz-23kHz ) < -70 dB (typ. -85 dB)
Common mode rejection: > 45 dB typical, 25 Hz to 15 kHz
● Built-in Stereo Gen. Specs
Stereo System: EBU/CCIR/FCC standard “Pilot Tone System”
Pilot Tone Frequency: 19 kHz ± 1 Hz
Pilot Tone Deviation: ± 7 kHz nominal
38 kHz Suppression: > 70 dB (typ. 85 dB)
38 kHz Tone Generation: Internal Crystal
38 kHz Tone Precision: 38 kHz ± 2 Hz
Phase response: 19/38 kHz 0°± 2°, internally adjustable
Stereo Separation: 30-80 Hz >53 dB, 80 Hz-15 kHz >60 dB
Crosstalk attn. (M / S):> 40 dB, 40 Hz to 15 kHz (typ. 55 dB, 100 Hz to 8 kHz)
Audio Spurious Products: > 53 kHz < 50 dB
THD on L & R channels: < 0.03%, 30 Hz-15 kHz
Audio Filter Attenuation: > 55 dB @ 19 kHz; >45 dB 19 to 50 kHz; > 50 dB to 100 kHz (typ.)
● Audio Inputs (on rear panel)
Baseband / Composite / MPX Input:
1 BNC connector, unbalanced, 2 kW.
Input level range for 75 kHz Deviation: – 6 to +12 dBm, adjustable from menu
SCA / RDS / AUX Input: BNC connector, unbalanced, 2 kW. Input level range: – 6 to +12 dBm, adjustable from menu
L&R or Mono Input: 2 XLR connectors, 600W balanced or unbalanced, switchable, or
10kΩ unbalanced, input level range for 75 kHz Deviation: -6 to +12 dBm, adjustable from menu
AES-EBU input (optional) XLR connector and optional optical connector
● Other Connectors
(on rear panel)
19 kHz Output: 1 BNC connector, unbalanced,
Pilot tone 2 Vpp 19 kHz
Baseband / Composite / MPX Output:
1 BNC connector, unbalanced
DB25 for Analog Telemetry & Remote Control (include RF forward & reflected PWR, ext. interlock, contacts for ON/STBY & much more).
RJ 45s: LAN / WEB connection, optional VOIP, optional SNMP2
USB A: for SNMP2 Software
DB9: RS485 for interconnection w/ other units
SMAs for 10 MHz external reference port and for 1 pps port (optional).
● Front Panel Connectors
USB C or micro: Front panel port to access user manual file & other technical test reports
RF Monitor: -36 dBc ±3 dB, 50 W BNC
● Environmental
Storage temperature: -20°C to + 60 °C
Operating temperature: -10°C to + 45°C
Relative humidity: 90% (non-condensing)
Max operating altitude: 3000 m.
Max ambient field strength: ≤3 V/m; ≤ 4 A/m
Cooling: Forced air (easily replaceable fan)
● Physical & Electrical
Front panel: 483mm (19″) W x 88mm (3 1/2”) H (two standard rack spaces high)
Cabinet depth from front panel:
approximately 480 mm (18 3/4”)
Approximate Weight: 15 lbs (7 Kg)
Approx. Packed Weight: 22 lbs (10 Kg)
AC Power Requirement: Full range,
115-220V [±15%] 50/60Hz single phase.
Approx. Power Consumption @ Full PWR:
XL50: 110 VA; XL150: 250 VA; XL300: 450 VA
Available Readings include: FWD PWR, RFL PWR, Frequency, Audio Presence, Deviation, Preemphasis Status, Audio Input Selection, L & R Channels Modulation Level, Stereo Generator Enabled / Disabled, Audio Limiter Enabled / Disabled, VPA, IPA, Temperature, Efficiency, Status of FSK ID Keyer and many other readings & functions
All Bext products’ features & specifications are subject to change without notice
