Bext XL300, 300 Watt FM Transmitter

Bext XL300, 300 Watt FM Transmitter

• User manual & tech documentation accessible via front USB port even when unit is not powered
• Instant user programmability (local or remote) allowing for ideal backup to multiple stations
• Proportional Auto-Foldback of output power in the event of excessive VSWR
• Adjustable, user settable output power level with soft-start control
• Automatic power control maintains the output power at any pre-set level
• Modular layout with plug-in, easily replaceable circuits and parts
• Includes low pass/harmonic filter and meets or exceeds all FCC and CCIR requirements

RF Specifications
Nominal RF Output Power: 300 W user adjustable.
Power control stability: Better than 0.1 dB
RF Output Impedance: 50 Ω unbalanced
RF connector: Type N female
Frequency range: 87.6 – 107.9 MHz, front panel programmable in 10 kHz steps, synthesized, microprocessor controlled
Reference: 10 MHz TCXO
Off-lock attenuation: > 80 dBc
Lock-in time: Typically 7 sec
Type of modulation: F3E / F8E direct FM at carrier frequency
Frequency deviation: Nominal ±75 kHz, can be user set from ±50 kHz to ±100 kHz
Accuracy of deviation:< ± 2 dB from 87.6 to 107.9 MHz
Frequency drift:  1 kHz/year (due to internal TCXO aging). Can be user-calibrated
Short term stability: ± 1 ppm from -5 to +45 °C (100 Hz @ 100 MHz)
RF Harmonics: Exceeds EBU/CCIR/FCC requirements; < -76 dBc
RF Spurious: Exceeds EBU/ CCIR/FCC requirements; < -90 dBc min @ ±1 MHz

Audio General Specs
Preemphasis: Selectable Flat / 50 / 75 micros.
Preemphasis Precision: Better than ± 0.5 dB
Wideband Amplitude Response: ± 0.2 dB 30Hzto53kHz; ±0.2dB53kHzto100kHz
Wideband AM Asynchronous: (FM = no modulation, Ref. = 100 % AM, Unweighted, RMS detector, BW 30-200 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) -75dB/50μs -69dB/flat; Weighted (CCIR 468/2 – RMS detector) – 79 dB / 50 μs -72 dB / flat; Unweighted (RMS detector, meas. 20 Hz-23 kHz) – 86 dB / 50 μs – 80 dB / flat (stereo); Unweighted (RMS detector, meas. 20 Hz-23 kHz)-92dB/50μs-88dB/flat(mono)
IMD:70Hz/6kHz4:1RATIO<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 ±75kHzRef.=100%AM,RMSdetector, 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, 25Hzto15kHz

Built-in Stereo Gen. Specs
Stereo System: EBU/CCIR/FCC standard “Pilot Tone System”
Pilot Tone Frequency:19kHz±1Hz
Pilot Tone Deviation: ± 7 kHz nominal
38 kHz Suppression:>70dB(typ.85dB)
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; >45dB19to50kHz;>50dBto100kHz(typ.)
Audio Inputs (rear panel) Composite/MPX Input: 1 BNC connector, unbalanced, 10 k
Input level range for 75 kHz Deviation: -13 to +13 dBm, adjustable on rear panel
SCA / RDS / AUX Inputs: 2 BNC connectors, unbalanced, 10 k. Input level range: -20 to +13 dBm for 7.5 kHz, adjustable on rear panel
L&R + Mono Input: 2 XLR connectors, balanced or unbalanced; switchable 50  / 600 . Input level range for 75 kHz Deviation: -13 to +13 dBm, adjustable on rear panel
AES-EBU input (optional): XLR connectors

Other Connectors (rear panel)
19 kHz Output: 1 BNC connector, unbalanced, 4.7k. Pilot tone 1 Vpp 19 kHz Squarewave
DB25: Standard Analog Remote Control
DB9: five DB9 ports for RS485, RS232; AUX; standby/main for dual transmitter configuration
RJ 45: four RJ45s for LAN/WEB connections

Other Connectors (front panel)
USB: Standard type USB port
RF Monitor (not suitable for measuring harmonics): -36 dBc ±3 dB, 50  BNC
Baseband Audio Monitor: 50  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 (internal blowers)

Physical & Electrical
Frontpanel:483mm(19″)Wx88mm(31⁄2”)H (two standard rack spaces high)
Cabinet depth from front panel: 545 mm (211⁄2”)
Tot depth incl. front handles: 585 mm (23”)
Approx. Weight: 33 lbs (11 Kg)

Approx. Packed Weight: 37 lbs (20 Kg)
AC Power Requirement: 220 V [±15%] 50 / 60 Hz, single phase
Approx. Power Consumption @ Full Pwr: XL 150: 230 VA; XL 300: 440 VA XL500: VA

LCD Display Readings: Forward Power, Reflected Power, Frequency of Operation, Audio Presence, Deviation, Audio Input Selection, Preemphasis Status, Stereo Generator Enabled / Disabled, Audio Limiter Enabled / Disabled, L & R Channels Modulation Level, VPA, IPA, Temperature, Efficiency, Status of optional FSK ID Keyer, other misc. readings & functions

All features and specifications are subject to change without notice.