FT8一个周期15s, 前12s用于发射；但是我在使用wsjt-x，点击enable-tx的时候，发现如果当前时间正好落在一个周期的前12内（例如目前是第5s）,点击这个按钮也会立即发射，而不是等到下个周期；这样发射的数据不就不完整了吗，接受方是不是就无法解码了呢

实在没发到解码不了的 jtdx 也会猜啊猜

Jtdx真的很能猜，有时候只接受到一个周期后面六七秒都能解码出好几个

@"ba7nzl"#p69797 校准过了，时间没问题

@"BG5ELQ"#p69795 一个CQ还是挺长的，发不完整的话这咋猜，感觉很奇怪

@"Liridice"#p69804 没错，是这样的，有时候在一半的时间开始发射都来得及

@"Liridice"#p69804 确实，我只见过一次一行出两条消息的，还以为程序出bug了

一行出两条消息不是因为发送到一半变更内容导致的，那种消息是开了狐狸模式产生的信号，方便dx的时候提高通联速率

@"swimmingcat"#p70143 一次出两条或者多条消息，通常是远征模式。我说的那个操作方法，是一个实现“一个周期发两条信息”的偏门，大多都是偶然产生的（比如：一次通联结束转入CQ几秒钟之后，才发现上面还有个台要回，于是在发射周期中段更改了发送的信息），不会有人刻意用这个方法去提高回台效率（会累死）。

I would like to ask about the best time to use the wsjt-x for FT8 transmissions.

swimmingcat

In FT8, one cycle lasts 15 seconds, with the first 12 seconds used for transmission.
However, when I use wsjt-x and click the "enable-tx" button, I found that if the current time falls within the first 12 seconds of a cycle (for example, if it's currently the 5th second), clicking this button will immediately transmit, rather than waiting for the next cycle. This means that the transmitted data is incomplete, and the receiving end may not be able to decode it.

BG5ELQ

Not necessarily; the data may be redundant.

BG5ELQ

Even if a JTDX doesn't manage to decode it, they will still try to guess.

swimmingcat

BG5ELQ The CQ signal was quite long, and if it wasn't complete, how could I guess what it was? It feels very strange.

ba7nzl

Is the computer's time accurate?

swimmingcat

ba7nzl Calibration is complete, and the timing is correct.

BG5VLI

JTDX is really good at decoding; sometimes it can decode several things within six or seven seconds after a cycle.

Liridice

一个周期发77个信息位+14个校验位+83个纠错位，所以说FT8抗干扰能力很强。你可以测试一下，手动在每个周期第8秒的时候更改一下消息内容重新发射，对面能解出两条消息，而且后半段那条消息的RST要更强一些。

BG2EWI

Liridice That's right, sometimes it's possible to start launching even when only half of the time has passed.

swimmingcat

Liridice Indeed, I've only seen one instance where a single message was sent twice, and I initially thought there must be a bug in the program.

Liridice

swimmingcat Sending two or more messages at once is usually done in "expedition mode." The method I'm referring to is a workaround for sending "two messages per cycle," and it's mostly accidental (for example, after finishing a connection and transferring to CQ for a few seconds, you might realize there's another station that needs to be contacted, so you change the message being sent during the transmission cycle). No one intentionally uses this method to improve efficiency (it would just lead to exhaustion).

BG5VLI

The situation where a single transmission results in two messages isn't due to changes occurring mid-transmission. Instead, it's caused by the "fox mode" signal, which is designed to improve connectivity during DX (long-distance communication).

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