FT8, or: why Windows time syncing sucks!

Now: as we've all established that I'm a geek through-and-through, of course the idea of digital modes on HF caught my attention! So, I decided to give the 'ol "digital-mode-du-jour" a try, which happens to be FT8 (via WSJT-X):

A little description of FT8 (which would have helped me when I started with it):

FT8 is a "weak signal mode" that is really good at getting a QSO through even when a signal is down in the mud (ie: below the perceivable noise floor). So, even if you'd struggle to hear something on SSB voice, FT8 still may work.

What FT8 is:

  • A good mode for large signal-to-noise ratios (ie: noisy/hard-to-work environments)
  • A great mode for stacking-and-racking large numbers of QSOs
  • Kinda like a video game, in that your timing in responding to a CQ has to be good! 
What FT8 is not:
  • A mode for ragchewing: it's just not built-in to the software
  • A mode for when you can't get your computer's time to sync properly (more on this later!)
With all that being said: FT8 is damned fun when you start making QSOs. 

Warning: If you cannot get your computer's clock to sync within 0.5 seconds of a recognized time server (ie: an atomic clock), YOU WILL LIKELY NOT BE ABLE TO MAKE QSOs!

Let me re-iterate that point: FT8 is extremely time-slot (and accurate time) dependent. This means that everyone using FT8 needs to sync to a standard time server in order for QSOs to go through.

To explain this, let me first explain how FT8 works:

FT8 is split-up into 4 15-second time-slots (TS) per minute: slot 0 (0:00 through 0:14), slot 1 (0:15 through 0:29), slot 2 (0:30 through 0:44), and slot 3 (0:45 through 0:59). Depending on how you have your WSJT-X software set, you're either going to transmit in the odd TSs (default), or the even TSs. For example: say station 1 is "FT8AB" in grid AB12, and station 2 is "FT8XZ" in grid XZ89. A standard QSO goes like this (starting the count at TS0, with explanations in square-brackets):

TS0: CQ FT8AB AB12        [calling CQ with their callsign and grid square]
TS1: FT8AB FT8XZ XZ89  [responding to CQ with their callsign and grid square]
TS2: FT8XZ FT8AB R-05   [reply w/ signal read: -05 is in db below noise floor. bigger = better]
TS3: FT8AB FT8XZ R-12   [reply w/ their signal read]
TS4: FT8XZ FT8AB RRR   [reply with "RogerRogerRoger", an acknowledgement]
TS5: FT8AB FT8XZ 73       [standard 73 (ie: "best regards" message)]
TS6: FT8XZ FT8AB 73       [standard 73 message]

So, the above happens over a minute and 45 seconds, barring any dropped transmissions. If "auto-sequence" is enabled, WSJT-X is really good at formatting and replying with the appropriate messages. 

Now: a typical FT8 transmission takes close to all 15 seconds to transmit the encoded data (12.6 seconds, to be exact). Thus: if your computer's clock is off by a second or two, the receiver will not get your entire transmission and WSJT-X will discard it. 

In Linux, syncing your system clock to an NTP server is extremely easy! From the console, type "sudo ntpdate {NTP_SERVER_HERE}" (with time servers such as pool.ntp.org ). There: done. You can verify it by going to https://time.is 

Now, in Windows: this is not very easy. The guys over at Microsoft decided to not make the ntp infrastructure in Windows 10 (or server-side at time.microsoft.com) very accurate. The best I could do was 1 second of drift: good enough for government work, but not for FT8. This frustrated the hell out of me, as I was seeing the FT8 traffic, but no responses to my traffic what-so-ever. This is where I definitely recommend the Meinberg NTP client for Windows: it does the job, and does it well! Once Meinberg was installed and my system clock was synced, the QSOs just started dropping on my lap!

A note: I posted about my FT8 woes on Reddit's /r/amateurradio subreddit, and they helped get me squared away (ie: FIX YO TIME, FOOL!). I highly suggest you get a Reddit account and join /r/amateurradio, as those guys are pretty awesome!

BTW: /u/robonova-1 recommended that I watch this video for setting-up my 7300 for digital modes. I did, and it worked like a charm, so you can too! I also will copy/paste my recommendation I made on my Reddit post:

If you have a 7300 and an SD card, do what I did to make things easier:
  1. Reset your radio to factory default, and save a copy of this setting to the SD card (named "default")
  2. Make your digital-mode changes, and save those to the SD card (named "digital")
  3. Restore to "default" settings
  4. Make your analog (ssb/am/etc) changes, and save those to the SD card (named "analog")
  5. Now, you can easily move the radio from "digital-optimized" to "analog-optimized" with a few button presses.

Now that I have my coffee, I'm ready to watch radar. 

I went over to TARC on Saturday, and in 3 hours got 33 QSOs on FT8 on 40m, including 2 from Cuba! Here's a pic of a completed QSO with AB3WF (right-side window):

But I wasn't really hammering it too hard: this was also talking to the other guys in the shack at the time. If I had my own shack and tower, I bet I could get 25 QSOs/hour. But in one day at TARC, I got my first 16 states towards Working All States.

Now, let me talk for a second about the awesomeness that is PSKReporter! If you're using a digital mode, you need to use PSKReporter. Basically, it works like this:

  1. Hams using WSJT-X (or other PSKReporter-capable programs) see your callsign in their traffic (the left window), and report this (along with their callsign and gridsquare) to PSKReporter. 
  2. You go to PSKReporter, and enter your callsign (and mode/band if you want)
  3. You see where your signal is being heard at, in real-time. 
This is an infinitely-awesome tool for seeing how well your signal is getting out! Below is PSKReporter showing how my signal was doing at 30 watts when I was working at TARC on their 40m beam pointed northward:

All of the blue dots are stations reporting to PSKReporter. The blue dots with a time showing are ones that have heard my callsign and when they last heard it. So, PSKReporter is a great way to show how your signal is getting out! But, it only works well if everyone participates!

So: inside of WSJT-X's settings, click on the "Reporting" tab, and click "Enable PSK Reporter Spotting". There, done. Wasn't that easy?

Ok: Maybe video to come showing me working the mode. Maybe.


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