Setting up FT8

First, download and install the latest distribution from the WSJT-X project page. The documentation is well-written and useful.  The second release candidate features decoding improvements (a priori decoding) that increases the ability to work with weaker signals.  It seems to work awesomely.

Second, verify your system clock is set accurately. Seriously. The FT8 cycles are 15 seconds, of which 12.6 seconds are transmit, 0.5 – 1 seconds of decode & lookup, and the rest left up to you to make a response. On Mac, this is done via command-line:
sudo ntpdate -u time.apple.com
On Windows, use Dimension 4

Edit the preferences. In the General tab:

FT8 – General Settings

1. Enter your call sign.
2. Enter your Maidenhead grid.
3. This is optional, but if you choose your IARU region, it’ll help set up your frequency list later.
4. I like the program off by default as a reminder to set my system time.
5. There is some automation in place such that when it sends the “73” (“Best regards”), it’ll stop transmitting until you reenable it again.

The Radio tab is going to vary depending on what you own.
For my Elecraft KX3:

FT8 – Radio

1. USB device for the control cable.
2. I prefer having the computer control it rather than using tones (like my HT does).
3. This tells the radio to use data mode, which disables compression, the RX/TX EQ, and uses a low error-rate ALC.

From the KX3 manual

My Mac lacks a microphone, so I use an external USB dongle for both in and out.  Generally, you want to use as little volume as necessary to avoid overloading the card.

FT8 audio

Generally, I run with ALC (Automatic Level Control) — the ALC gain on the radio -showing 4-5 bars.  Some radios will require this off. Sound out from the radio (and into the sound card) is kept at a minimum.  See below.

The reporting tab has two items of interest:

FT8 – Reporting

1. When you detect a station, upload it to this (free) spotting service

PSK Reporter – used to help identify good/bad propagation

This is very useful because it lets you see that your station is being received.  The light purple arc is an estimate of where I’m being well-received.

2. There are supplementary utilities that can listen to the connection and automatically log for you. For example, I have JT-Bridge act as a layer to do lookups then instruct MacLoggerDX to upload them to QRZ.com. (Yes, this is overly complex.)

Finally, the first time you use wsjtx, or if you update, you’ll need to load in frequencies. Right-click on the main window and select Reset. I skim through these to remove bands my radio doesn’t support (e.g., 2200m, microwave frequencies):

FT8 – Frequencies

Right click and save these just in case you want to start over.

Okay, now that that’s set up, in the main window, there are three areas of interest:

FT8 – Main

Select the “Monitor” button to start listening.  The waterfall should start showing activity if there are users on.  Once a full 15-seconds has elapsed, you should start seeing those signals being decoded.

On the bottom, left is a meter showing input levels.  You want it to be in the green, ideally around 25-30db.  If it’s too quiet, the bar will be red meaning you’re not getting enough signal.  If it’s too loud, the bar will turn yellow indicating oversaturation.

The other two tick boxes are assistive automation.  Auto Seq will progress through the calling sequence on each cycle.  It’s necessary on FT8 because of the rapid cycle times (and my lack of cat-like reflexes).  The Call 1st is used when you’re calling CQ – it will automatically select the first response (either by time or, in the event of a tie, the sub-frequency you’re monitoring followed by the order of sub-frequency).

The standard messages, on the bottom, right, are automatically generated when you respond to someone (by double-clicking on their CQ) or someone responds to you.

So now, here’s how a sequence works.  The top quarter and bottom half of the graphic below are WSJT-X.  Sandwiched in the middle is a third-party listener, JT-Bridge, that does lookups of people and lets me know if they’re in a geographic area of interest.

First, I have the Monitor button (in green) selected, so it’s listening.  On the waterfall graph, outlined by the red rectangle are 15-second bursts of transmissions from NA4M calling CQ.  To response, I double-click on the CQ at 02:05:45.  (With JT-Bridge, I can also click on the one with the little number “3” next to it).

That action does the following things:

a) Pre-loads a set of standard messages (shown below) for the exchange.
b) Enables transmit (the Enable Tx button, currently off, because I’m doing this post-exchange)
c) Populates the Rx Frequency side with what’s happening on my receive frequency.

You’ll see in step (2), I respond, but he doesn’t acknowledge.  He repeats his CQ 30 seconds later.  I respond in step (3).  When he acknowledges me with my signal strength in step (4), the line turns purple to let me know that someone’s talking with me.  At that point, I return back to him with R-09 signal strength.  At step (5) he acknowledges receipt, and then exchange regards.

Buckle up, this goes faster than you’d think…

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