Bext Radio Transmitters

  • FM Receiverlcrfm.jpg (15128 bytes)                   

LCR FM                

  • 75 dB or better S/N
  • Available for the 87.5 -108 MHz FM band, can be custom ordered on any 108 -1000 MHz frequency
  • Direct front panel programmability
  • Superior MPX and SCA performance
  • Excellent RF immunity receiver, designed to withstand the most hostile RF environments
  • 50 dB minimum stereo separation
  • 0-12V DC input for direct hook-up to back-up battery
  • Ideal for translator applications in conjuction with one of the BEXT exciters and amplifiers
  • Meets or exceeds all FCC and CCIR requirements
  • Option 75: 75 kHz audio cutoff instead of standard 99 kHz; (will not pass 92 kHz SCA)
  • Option HR: Higher Rejection of very strong adjacent channels
 
General
Frequency Range: 87.5-108 MHz (LCR FM) Can be custom ordered on any 108-1000 MHz frequency)
Distortion, THD: Stereo demod., decoded and de-emphasized 30 Hz to 7.5 kHz: < 0.05 % (typ 0.025%) on "wide", <0.08% (typ 0.04%) on "medium", <0.15% (typ 0.06%) on "narrow"; at 1 kHz <0.02% (typ 0.01%)on "wide", <0.03% (typ 0.015%) on "medium", 0.05% (typ 0.025%) on "narrow"
Mono demodulated and de-emphasized: 30 Hz to 7.5 kHz: <0.1 % (typ 0.06%)at 1 kHz <0.04% (typ 0.02%)
Distortion, IMD: Intermodulation at demodulated output, two tone with 1 kHz difference frequency; 5-15kHz, D2 <0.05%, D3 <0.1% 15-53 kHz, D2 <0.12%, D3 <0.3% 
Stereo Separation: 30 Hz to 15 kHz, >60 dB (typ 65) on "wide", >50 dB (typ 55) on "medium", >45 dB (typ 50) on "narrow"
Crosstalk: 50 dB or better, stereo subchannel to main channel or main channel to stereo subchannel
Signal to noise ratio: 80 dB (typ 85) with 75 kHz deviation and 400 Hz frequency modulation (mono) 75 dB (typ 80) with 75 kHz deviation, demodulated, de-emphasized left or right (stereo)
Composite amplitude response, models with 97 kHz audio cutoff: +/-0.1 dB or less, 30 Hz-53 kHz
+/- 1 dB or less, 53 kHz- 75 kHz
+/- 2 dB or less, 75 kHz- 100 kHz
Composite amplitude response, models with 75 kHz audio cutoff: +/- .1 dB or less, 30 Hz-53 kHz
+/- 2 dB or less, 53 kHz-75 kHz
Data/subcarrier port (LCR STL only): +/-5 dB or less, 100-200 kHz
Composite phase response: +/- 0.1 from linear phase, 0 Hz-53 kHz
RF Input Connector/Impedance: Type "N" female, 50 Ohm
Frequency Programmability: From front panel
Sensitivity: Monaural (demodulated, de-emphasized):
5 mV for S/N >50 dB
15 mV for S/N > 60 dB (typ 9 mV)
50 mV for S/N > 65 dB
150 mV for S/N >70 dB
1.5 mV for S/N > 80 dB (typ 88 dB)
Composite (left or right channel, demodulated, de-coded, de-emphasized): 5 mV for S/N > 30 dB
15 mV for S/N > 40 dB
50 mV for S/N > 55 dB
150 mV for S/N > 60 dB (typ 85 mV)
mV for S/N >75 dB (typ 80 dB)
Selectivity (static), with IF on "narrow": 5 dB IF bandwidth +/- 100 kHz
20 dB IF bandwidth +/- 200 kHz
50 dB IF bandwidth +/- 300 kHz
Over 80 dB IF bandwidth +/- 500 kHz
Selectivity (static), with IF on "medium": 3 dB IF bandwidth +/- 100 kHz
12 dB IF bandwidth +/- 200 kHz
30 dB IF bandwidth +/- 300 kHz
60 dB IF bandwidth +/- 500 kHz
Over 80 dB IF bandwidth +/-600 kHz
Selectivity, dynamic (admissible proximity/ratios of adjacent signals for unaffected performance):

 

 With IF on "narrow" and 75 kHz audio cutoff:
At:                      Unwanted signal must be:
0 kHz                 <-43 dB below desired signal
100 kHz             <-22 dB below desired signal
 200 kHz            <+12 dB above desired signal
 300 kHz            <+35dB above desired signal
400 kHz             <+36 dB above desired signal
With IF on "narrow" and 97 kHz audio cutoff::

At:                      Unwanted signal must be:
0 kHz                 <-43 dB below desired signal
+/- 100 kHz       <-30 dB below desired signal
+/- 200 kHz       <+9 dB above desired signal
+/- 300 kHz       <+32 dB above desired signal
+/- 400 kHz       <34 dB above desired signal
With IF on "medium" and 75 kHz audio cutoff:

At:                      Unwanted signal must be:
0 kHz                 <-46 dB below desired signal
100 kHz             <-30 dB below desired signal
200 kHz             <-3 dB below desired signal
300 kHz             <+16 dB above desired signal
400 kHz             <+23 dB above desired signal
Receivers normally shipped with 97 kHz audio cutoff; 75 kHz audio cutoff on request, not field selectable, specify with order.  NOTE: Option HR allows withstanding of unusually strong RF fields within +/- MHz (ex. without HR, 200 mV/ -61 dBm of desired signal with 70 mV/ -10 dBm of interfering signal MAX; ex. with HR, 60 mV/ -71 dBm of desired signal with 224 mV 0 dBm of interfering signal MAX. Beyond 1 MHz, HR offers no advantages).

 

 
Multimeter: Four function diagnostic aid, peak and semipeak modulation meter
Outputs: Four BNCs with + and - polarity available, balanced and unbalanced and a 6.3 mm jack female for headphones
IF 10.7 MHz: BNC connector
Carrier detector: BNC connector
All levels: factory set for 3.5Vp-p (1.237 Vrms/ 4.1 dBm), adjustable -6 to +6 dB
Ambient Temperature Range: 0 to 40 C (32 to 104F) Operational from -20 to 50 C (-40 to 122 F)
AC Input Power: 120 or 240 VAC 
50/60 Hz, 30 VA
DC Input Power: 12.5 V (+/-0.1 V) 2 A, 10 mVp-p max ripple
Front Panel Size: 483 mm (19") W x 132 mm (5-1/4") H (3 standard rack spaces high)
Overall Depth: 483 mm (19")
Net Weight: 12 kg (26.4 lbs)

 

(c) 2004 BEXT Corporation USA