| 词条 | MT63 | |||||||||||||||||||||||||||||||||||||||||||||||||
| 释义 |
MT63 is a digital radio modulation mode for transmission in high-noise situations developed by Pawel Jalocha SP9VRC. MT63 is designed for keyboard-to-keyboard conversation modes, on HF amateur radio bands. Features and AttributesMT63 distributes the encoding of each character over a long time period, and over several tones. This code and symbol spreading implementation is key to its robustness under less than ideal conditions. The MT63 mode is very tolerant of mistuning, as most software will handle 120 Hz tuning offsets under normal conditions.
MT63 LatencyOne shortcoming of MT63 is that robustness is somewhat compromised with the short interleaver. Latency (delay between transmitted characters) is more than 6 seconds with the long interleaver. The typical character transmission delay is 12.8 seconds with Long Interleave Mode.
Media{{Listen|filename=MT63 sample.ogg|title=A sample MT63 transmission|description=The text "Welcome to Wikipedia, the free encyclopedia that anyone can edit." sent as MT63-1K.|format=Ogg}}MT63 is seeing a resurgence in its popularity on shortwave with the VOA Radiogram[1] but the software used to encode the text is not using the Varicode that MT63 used in its original design. Modern software that codes MT63, such as Fldigi, has opted for base128[2] that is essentially ASCII-7. However, the only interleaving options have become long and short, as the medium interleaving mode has become redundant. MT63 has been mooted as a modulation format for Time Signal Stations, but the implied system does not use Vericode.[3] See also
References1. ^{{cite web|title=VOA Radiogram|url=http://voaradiogram.net/}} 2. ^{{cite web|title=MT63 Modes|url=http://www.w1hkj.com/FldigiHelp-3.21/Modes/MT63desc.htm}} 3. ^{{cite web|title=Wide Area Time Service with Extended Features|url=http://hireme.geek.nz/distributed-time-service.html}} Related links
1 : Quantized radio modulation modes |
|||||||||||||||||||||||||||||||||||||||||||||||||
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。