AN/PRC-128
Contents
Overview
The Scope Shield Radio System consists of the following;
- Adapter Group OF-185/PRC (VA)
- Radio frequency power amplifier (PA)
- AN/PRC-128 handheld radio (PRC).
The items repairable at depot level are the power supply/audio (PS/A) assembly of the VA, the complete PA (including alternate module) and the RT portion of the PRC/128 (including alternate module).
- The AN/PRC-128 radio system (PRC) consists of the following
- A receiver/transmitter (RT),
- Low band long range (LBLR) antenna;
- Low band short range/high band (LBSR/HB) antenna;
- Low band (30 to 88 MHz) and high band (130 to 174 MHz) RF/IF modules (one installed, other is alternate);
- Carrying pouch;
- Lanyard
- Two rechargeable nickel-cadmium (NICAD) batteries.
The PRC is a two-band handheld receiver-transmitter. The PRC provides short range, ground-to-ground voice communications in the low VHF-FM (30 to 88 MHz) and high VHF-FM (130 to 174 MHz) bands.
- 10-channel Operator Programmable-frequencv Capability
- The RT stores up to ten programmed channels (12.5 kHz increments) anywhere in the operating frequency range. A programmed RT can program another radio with channel/frequency information via a frequency transfer cable.
- Antenna Matching Switch
- The thumbwheel switch selects the proper antenna matching network for the transmit frequency. The "50" position provides a direct 50
ohm interface for test use. The "50" position is used for 130 to 174 MHz operation or with any 50 ohm external antenna. An antenna warning tone is activated if the switch position is incorrect with respect to the operating frequency.
- Warning Tones.
- The RT generates two separate warning tones; a low battery tone and an antenna mismatch tone.
- Liquid Crystal Display.
- A five-digit display indicates frequency, operational mode, and programming information to the operator.
- Half-duplex operation.
- The PRC can transmit and receive utilizing a separate frequency for each channel programmed in the half-duplex mode.
Technical Specifications
RT GENERAL CHARACTERISTICS
- Frequency ranges
- 30.0000 to 87.9875 MHz and 130.0000 to 173.9875 MHz
- Minimum channel spacing
- 25 kHz (+/- 25 kHz spacing to operate; can program in 12.5 kHz increments)
- Available channels
- 4640 (30-88 MHz band), 3520 (130-174 MHz band)
- Preset channels
- 10 (stored in non-volatile memory)
- Operating modes
- Clear Voice (Simplex and Half Duplex) FM
- Operating voltage
- 11 to 16 Vdc, 400 mAdc maximum.
- Low battery warning tone
- Four 400 Hz beeps at six second intervals when battery voltage drops below preset level
- Antenna mismatch tone
- 1000 Hz tone at 2 second intervals if selected operating frequency and ANT match switch position do not agree
RT RECEIVER CHARACTERISTICS
- Sensitivity
- 0.5 microvolts for 12 dB SINAD*
- Selectivity (+/- 25 kHz)
- -50 dB for 30-88 MHz, -60 dB for 130-174 MHz
- Squelch sensitivity
- 0.5 microvolts (maximum), noise operated
- Spurious response
- -60 dB
- IF rejection
- -60 dB
- Audio output
- Power
- 100 mW (nominal) into 47 ohms
- Distortion (@ 100 mW)
- 10% (maximum)
- Frequency response
- 300 to 3000 Hz (+1, -6 dB)
- Hum and noise
- Unsquelched
- 30dB below rated audio out
- Squelched
- 50 dB below rated audio out
- SINAD = Signal + Noise + Distortion Noise + Distortion
RT TRANSMITTER CHARACTERISTICS
- Power output
- 1.0 watt (minimum into 50 ohms)
- Spurious harmonic attenuation
- 43 dB below carrier (min.)
- Frequency stability
- 5 ppm (maximum) of operating frequency
- Audio
- Frequency response
- 300 to 3000 Hz (+1, -4 dB)
- Harmonic distortion
- 10% (maximum)
- Modulation
- +/-3 kHz, limited at 5 kHz (130-174 MHz)
- +/-4.5 kHz limited at 7.5 kHz (30-88 Mhz)
- FM hum and noise
- 30 dB below nominal deviation level (Low Band only)
- Squelch tone
- 150 +/- 2Hz'
PA CHARACTERISTICS
- Frequency ranges
- 30.0000 to 87.9875 MHz and 130.0000 to 173.9875 MHz
- Input power
- 25 - 28 Vdc, 3.0 Adc maximum
- RF Power Output (50 ohm load)
- BYPASS mode;
- 1 watt (ref. rf input)
- AMPL mode;
- 10 watts minimum, 20 watts maximum (internal adjust)
- Spurious harmonic attenuation
- 60 dB below carrier (minimum)
- Reference rf input level
- 0.25 watts minimum from RT
- RCV mode signal loss
- 1.0 dB max
PS/A CHARACTERISTICS
- Input power
- 10 to 32 Vdc; 150 watts max.
- Output power
- 14.5 to 15.5 Vdc @ .5 Adc max (RT).
- 26.0 to 27.0 Vdc @ 3.0 Adc max (PA).
- Charger current
- Nominal
- 30 mA
- Short-circuit
- 90 mA
- RCV Audio Output
- Power
- 2.0 watts nominal into 8 ohms
- Distortion @ 2.0 Watts
- 10.0 % maximum
Images
Reference Files
- MAINTENANCE INSTRUCTIONS WITH ILLUSTRATED PARTS BREAKDOWN
- RADIO SET
- AN/PRC-128 (PN 901608-801)
- RP [sic] POWER AMPLIFIER (PN901603-801)
- ADAPTER GROUP
- OF-185/PRC (901602-801)
- 18 November 1999