background image

3

DR-142 SPECIFICATIONS

Wide band

Narrow band

  

25 kHz    

   12.5 kHz

Sensitivity (12 dB SINAD):

0.25 µV

0.25 µV

Adjacent channel:

-70 dB

-60 dB

Spurious rejection:

-60 dB

-60 dB

Image rejection:

-80 dB

-80 dB

Intermodulation:

-65 dB

-65 dB

FM hum and noise:

-45 dB

-40 dB

Conducted spurious:

-57 dBm

-57 dBm

Receiver attack time:

 < 30 ms

 < 30 ms

Noise squelch attack time:

 < 15 ms

 < 15 ms

RSSI squelch attack time:

 < 5 ms

<  5 ms

RSSI squelch sensitivity

:

Manually adjustable; factory set for –108 dBm

Noise squelch sensitivity

:

Manually adjustable; factory set for 20 dB SINAD @ 1.5 kHz deviation
( 3.0 kHz used for wideband)

AUX OUT frequency response

: 6 - 3000 Hz @ +1 / -3 dB

Audio Output

>700 mW into 8 

, with less than 5 % THD

Sub D 15 Pin Connector

   The DR-142 is equiped with a 15 pin female sub D connector with the following functions:

Pin#     Function

1 least significant channel select bit (CS0)
2 channel select 1 (CS1)
3 Most significant channel select (CS2)
4 N/A
5 N/A
6 + 8 to 15 VDC input
7 N/A
8 auxilary ouput
9 PC programing port
10 N/A
11 Auxilary monitor input (pull to ground to open squelch)
12 Speaker output
13 Carrier detect output (pulls to 5 VDC through 390 ohms)
14 N/A
15 ground

INTRODUCTION

Summary of Contents for DR-142

Page 1: ...0 PRELIMINARY DR 142 PROGRAMABLE VHF FM RECEIVER MODULE OPERATING AND SERVICE MANUAL RITRON INC...

Page 2: ...T 6 4 PROGRAMMING THE RADIO 7 PROGRAMMING THE RADIO USING A PC COMPUTER 7 Programmable Features 7 COMPUTER SOFTWARE COPYRIGHTS 7 5 DR 142 THEORY OF OPERATION INTRODUCTION 8 POWER SUPPLY AND VOLTAGE DI...

Page 3: ...els 8 Independent RX frequencies Synthesizer Step Size 5 kHz Frequency Stability 2 5 PPM 30 to 50 C Tone Code Signaling CTCSS Quiet Call and DCS Power Supply 8 to 15 VDC Battery Drain RX Standby 20 mA...

Page 4: ...ensitivity Manually adjustable factory set for 20 dB SINAD 1 5 kHz deviation 3 0 kHz used for wideband AUX OUT frequency response 6 3000 Hz 1 3 dB Audio Output 700 mW into 8 with less than 5 THD Sub D...

Page 5: ...to this equipment Such modifications could void the user s authority to operate the equipment MAINTENANCE INFORMATION Surface Mount Repair RITRON surface mount products require special equipment and s...

Page 6: ...re that no voltage transients are present 6 Soldering Use a grounded soldering iron for soldering CMOS circuitry 7 Lead straightening tools When straightening CMOS leads provide ground straps for the...

Page 7: ...rogramming cable The other end of the programming cable connects to the PC s serial port 25 pin D sub connector The appropriate DR 142 programming software must be run for configuring the transceiver...

Page 8: ...model displayed will be that of the last radio read by the software and the default parameters for that radio To read the radio contents click radio on the menu bar and then read radio Allow several s...

Page 9: ...lled oscillator TCVCXO operating at 14 4 MHz The Pin 4 output of the TCVCXO provides a reference for the frequency synthesizer U401 at Pin 8 The reference oscillator also feed pin 7 of the U301 microc...

Page 10: ...here a low pass filter R323 and C309 removes spurious second IF output prior to application to the voice tone or squelch conditioning audio circuitry Two types of squelch circuits exist on the DR 142...

Page 11: ...program frequency information Also used for flash programming MOSI 16 CLK output sends serial data clock pulses to frequency synthesizer Also used in flash programming MISO 17 output is set permanent...

Page 12: ...o readjust do the following 1 Make sure that the unit is at room temperature approximately 25 C 2 Set the RF communications test set to the transmit frequency counter mode 3 Select low edge channel on...

Page 13: ...feated by turning the R144 pot fully counterclockwise or removing Q110 To adjust squelch levels for simultaneous use do the following Set RSSI squelch level first 1 Temporarily defeat noise squelch po...

Reviews: