1-18
THEORY OF OPERATION
2.6
Voice Storage (optional)
The Voice Storage (VS) option can be used to store audio signals coming from the receiver or from
the microphone. Any stored audio signal can be played back over the radio’s speaker or sent out via
the radio’s transmitter.
The Voice Storage option can by placed on the controller section or on an additional option board
which resides on option board connector J0551. Voice Storage IC U0301 provides all required
functionality and is powered from 3.3 volts regulator U0351 which,is powered from the regulated 5
volts. Dual shottky diode D0301 reduces the supply voltage for U0301 to 3 volts. The
microprocessor controls U0301 via SPI bus lines CLK (U0301-8), DATA (U0301-10) and MISO
(U0301-11). To transfer data, the µP first selects the U0301 via address decoder U0141, line VS CS
and U0301 pin 9. Then the µP sends data through line DATA and receives data through line MISO.
Pin 2 (RAC) of U0301 indicates the end of a message row by a low state for 12.5 ms and connects
to µP pin 52. A low at pin 5 (INT), which is connected to µP pin 55 indicates that the Voice Storage IC
requires service from the µP.
Audio, either from the radio’s receiver or from one of the microphone inputs, emerges the ASFIC
CMP (U0221) at pin 39, is buffered by op-amp U0341-1 and enters the Voice Storage IC U0301 at
pin 25. During playback, the stored audio emerges U0301 at pin 20. To transmit the audio signal it is
fed through resistive divider R0344 / R0345 and line VS MIC to input selector IC U0251. When this
path is selected by the µP via ASFIC CMP port GCB 4, the audio signal enters the ASFIC CMP at
pin 48 and is processed like normal transmit audio. To play the stored audio over the radio’s speaker,
the audio from U0301 pin 20 is buffered by op-amp U0341-2 and fed via switch U0342 and line FLAT
RX SND to ASFIC CMP pin 10 (UIO). In this case, this ASFIC CMP pin is programmed as input and
feeds the audio signal through the normal receiver audio path to the speaker or handset. Switch
U0342 is controlled by the µP via ASFIC CMP port GCB 4 and feeds the stored audio only to the
ASFIC CMP port UIO when it is programmed as input.
Summary of Contents for 6864115B62-C
Page 1: ...Professional Radio GM Series Detailed Service Manual 6864115B62 C ...
Page 2: ...ii ...
Page 4: ...iv ...
Page 5: ...Professional Radio GM Series Service Maintainability Issue July 2007 ...
Page 8: ...ii ...
Page 22: ...2 10 MAINTENANCE ...
Page 25: ...Professional Radio GM Series Controlhead Service Information Issue July 2007 ...
Page 77: ...Professional Radio GM Series Controller Service Information Issue May 2007 ...
Page 100: ...2 2 TROUBLESHOOTING CHARTS ...
Page 104: ...3 4 Controller schematics parts list ...
Page 154: ...3 52 Controller T12 Schematic Diagrams ...
Page 155: ...Professional Radio GM Series VHF 136 174MHz Service Information Issue May 2007 ...
Page 164: ...1 6 MODEL CHART AND TECHNICAL SPECIFICATIONS ...
Page 176: ...2 12 THEORY OF OPERATION ...
Page 186: ...3 10 TROUBLESHOOTING CHARTS ...
Page 190: ...4 4 VHF PCB SCHEMATICS PARTS LISTS ...
Page 252: ...4 66 VHF 1 25W PCB 8471235L02 Schematics VHF 136 174 MHz IF ...
Page 256: ...4 70 VHF 1 25W PCB 8471235L02 Schematics ...
Page 257: ...Professional Radio GM Series UHF 403 470MHz Service Information Issue May 2007 ...
Page 266: ...1 6 MODEL CHART AND TECHNICAL SPECIFICATIONS ...
Page 366: ...2 12 THEORY OF OPERATION ...
Page 372: ...3 6 Low Band TROUBLESHOOTING CHARTS ...