Receive Signalling Circuits
4-16
Theory of Operation
7.3
Alert Tone Circuits
When the software determines that it needs to give the operator an audible feedback (for a good key
press, or for a bad key press), or radio status , it sends an alert tone to the speaker.
It does so by sending SPI BUS data to U0103 which sets up the audio path to the speaker for alert
tones. The alert tone itself is generated by the AFIC.
The allowable internal alert tones are 410, 820, and 1640Hz. In this case a code contained within
the SPI BUS load to the AFIC sets up the path and determines the tone frequency, and at what
volume level to generate the tone. (It does not have to be related to the voice volume setting).
Inside the AFIC, this signal is routed to the alert tone generator; the output of the generator is
summed into the audio chain just after the RX audio de-emphasis block. Inside U0103 the tone is
ampliÞed and Þltered, then passed through the 8-bit digital volume attenuator, which is typically
loaded with a special value for alert tone audio. The tone exits at U0103-23 and is routed to the
audio PA like receive audio.
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Содержание GM950E
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Страница 4: ...Cautions and Warnings iv h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 6: ...Cautions and Warnings vi h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 8: ...Contents viii Service Manual h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 10: ...Table of Contents 1 ii Introduction h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 14: ...GM950E GM950i Technical SpeciÞcation 1 4 Introduction h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 16: ...Table of Contents 2 ii Model Chart and Accessories h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 20: ...Table of Contents 3 ii Maintenance h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 38: ...Table of Contents 4 iv Theory of Operation h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 87: ...UHF Main Board Supply Voltage 5 24 Schematic Diagrams and Parts Lists h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 90: ...5 28 Schematic Diagrams and Parts Lists h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 96: ...UHF Main Board Synthesizer 5 36 Schematic Diagrams and Parts Lists h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 119: ...VHF GM950E Main Board Controller 5 68 Schematic Diagrams and Parts Lists h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 122: ...VHF Main Board Supply Voltage 5 72 Schematic Diagrams and Parts Lists h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 125: ...5 76 Schematic Diagrams and Parts Lists h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 131: ...VHF Main Board Synthesizer 5 84 Schematic Diagrams and Parts Lists h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 144: ...5 102 Schematic Diagrams and Parts Lists h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 148: ...Main Board Control Head P 5 108 Schematic Diagrams and Parts Lists h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 150: ...Table of Contents 6 ii 216 246MHz Specific Information h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 152: ...Table of Contents 6 1 ii Model Chart and Technical Specifications h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 156: ...Technical Specification 6 1 4 Model Chart and Technical Specifications h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 158: ...Table of Contents 6 2 ii Radio Tuning Procedure h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 194: ...Table of Contents 6 4 ii PCB Schematic Diagrams and Parts Lists h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 216: ...Table of Contents A ii PL CTCSS Codes h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 218: ...Self Quieting Frequencies A 2 PL CTCSS Codes h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 220: ...Table of Contents B ii External Device Connectors h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 224: ...Microphone Connector B 4 External Device Connectors h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 226: ...Table of Contents C ii Radio Conversion h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 228: ...How to alter the radio for Base Station Operation C 2 Radio Conversion h t t p w w w m y r a d i o 1 6 8 n e t ...