User's Manual Part 1
Table Of Contents
- Health and Safety
- Customer Support
- Abbreviations
- Overview
- Specification
- Operation
- Overview
- T6T VHF Amplifier
- Drive Assembly
- Setting Up and Operation
- Normal Operation
- Using the Scroll/Select Switch
- Screen Protocol
- Menu System
- Menu Lock Screen
- Control Screen
- Notes for Setting Up the Transmitter
- Changing the Transmitter’s Operating Frequency
- To Store and Recall Frequency Channels
- To Initiate a BIT Test
- Standby Mode
- Settings
- AM-Voice Settings Procedure
- AM-MSK Mode Settings Procedure
- Mode 2 Settings Screen
- Mode 3 Settings Screen
- Polarities Screen AM-Voice and AM-MSK
- Mode 2 and Mode 3 Polarity Settings
- AM-Voice and AM-MSK BIT Screen
- Mode 2 and Mode 3 BIT Screen
- Software Configuration Screens
- Band Edges
- BIT Status Warning Screens
- Installation
- Warnings and Cautions
- Introduction
- Installing the Transmitter
T6T 300 Watt VHF Transmitter Page 27 Specification
Mode 2
Mode 2 parameters are identical to AM-Voice mode with the following exceptions.
RF Power Rise Time
The transmitter produces more than 90% of full power output within the first 2 symbols of the power
stabilization segment, which is the first segment of the training sequence and consists of 4 symbols each
representing 000.
RF Power Decay Time
The output power decays by more than 20 dB within 2.5 symbols of the middle of the final symbol.
Channel Spacing
25 kHz channel spacing only.
Transmitter Modulation Characteristics
Mode 2 uses Carrier Sense Multiple Access (CSMA) differentially encoded 8-phase shift keying
(D8PSK), using a raised cosine filter with α=0.6 (nominal value), emission designator 14K0G1DE.
Information is differentially encoded with 3 bits per symbol transmitted as changes in phase rather than
absolute phase. The data stream is divided into groups of 3 consecutive data bits, least significant bit
first. Zeros are padded to the end of transmissions if needed for the final channel symbol.
Modulation Rate
The symbol rate is 10,500 symbols/second (±0.005%), resulting in a nominal bit rate of 31,500 bits/s.
RMS Phase Error
The RMS phase error is less than 3°. The error vector magnitude is less than 6%.
Phase Acceleration
The total frequency change during the transmission of the unique word is less than 10 Hz. After this, the
phase acceleration is less than 500 Hz/s.
Transmitter Control
All control information and data for transmission is transferred via the HDLC connector. Control
information to an associated receiver is passed via the T1/E1 connector. Data from the receiver is also
passed back via the T1/E1 connector and then transferred to the Mode 2 computer via the HDLC
connector. This is illustrated in the Installation topic of this CD.
Time Out
The transmitter automatically dekeys if a transmission exceeds 10 seconds. No fault is flagged and the
transmitter keys again for the next transmission.