Beaconing Five Modes in Twenty Minutes

Posted on Friday, April 7th, 2017 at 9:10 pm in

While WSPR’ing across multiple bands (“band hopping”) has been done before, I thought it might be interesting to do five different modes on the same band. It was easier done than said!

Argo SlowHell callsign

Argo SlowHell callsign

I was sitting with a customer’s QRP-Labs Ultimate3S beacon on my bench, all built up and ready to test. It was a single band version with the LPF for 40m installed. Nicely constructed and in perfect working order.

After sweeping the filter and adjusting the LCD brightness and setting the output bias (all of 5 minutes – these are very easy beacons to build) I wondered what I could do as a “torture test” because WSPR’ing on 40 meters is so … common?

It occurred to me that if I can’t jump to five or six different bands, why don’t I jump to five different modes?

And that, as they say, is how the fight started.

Setting your Frames
Before using the Ultimate3S beacon, you have to enter your callsign and a few other basic details. The little Ultimate3S beacon has two pushbuttons on the front with which you can set and select your choices, by running through a menu system. I see it as two separate tasks (I’ll explain below) and a little bit of preparation will help you along nicely.

The first decision you should make is how often you want to repeat your message(s). There is an informal arrangement to repeat a WSPR message not more frequently than 10 minutes, with 20 minutes probably a better choice.

To start with, let us hypothetically hop to 5 bands:

Each WSPR frame takes about two minutes and must start exactly on an even minute boundary. I have arbitrarily decided to start on top of the hour at 00:00:00, and each consecutive transmission will start on the next two-minute boundary e.g.
00:00:00 First transmission frame – 40m WSPR
00:02:00 Next transmission frame – 30m WSPR
00:04:00 Next transmission frame – 20m WSPR
00:06:00 Next transmission frame – 15m WSPR
00:08:00 Next transmission frame – 10m WSPR
00:10:00 Beacon calibrates after each transmission cycle
This is how we used to do it for “WSPR-2” but it is very important to note that each mode has its own peculiarities and for example JT9/JT65 may use 1 minute frames and WSPR-15 uses 15 minute frames. I’m using WSPR-2 to make things simpler.

Task One: Choose your Cycle
In the above example you will notice that the last transmission starts exactly on the eighth minute and lasts for almost two minutes. There is barely 5 seconds left before the tenth minute begins. This is a BIG problem because the beacon needs time to calibrate the synthesizer, an activity which can take 30 seconds or 60 seconds or whatever you have chosen in your setup. Clearly, if the beacon starts exactly on the tenth minute, it will still be busy with calibration when the wake-up horn blows for the next cycle. Bad news!

Thus, in the above example I could choose a 12-minute cycle, which is fine (six cycles per hour), but it might just be better to give it a small break and start your next cycle on 20 minutes into the hour, leaving a few minutes for breathing space.

On the other hand, nothing prevents you from running a hard 24 x 7 x 365 schedule with no breaks. It is not a technical issue, it is just good manners to leave a break.

Task Two: Choose the contents of your Frames
Now that we have an idea of how long we want to make our cycle, we can decide the payloads for each frame. As I said before, if we want to only do WSPR we would end up with five frames like we did in Figure 1.

However, if we only have one band with only one LPF (Low Pass Filter) fitted, we can choose to hop between modes. The little Ultimate3S can do 18 modes standard out of the box, and some of those modes even have sub-modes.

A simple choice would be to target the more popular modes that are easily spotted. Let us put WSPR in the first frame, followed by a QRSS frame, then some SlowHell which is a gorgeous mode, then a CW-ID because it might be good manners and finally a JT65B because I have never heard what it sounds like.
Here is a concept:
Starting on the top of the hour again:
00:00:00 First transmission frame – 40m WSPR
00:??:00 Next transmission frame – 40m QRSS
00:??:00 Next transmission frame – 40m SlowHell
00:??:00 Next transmission frame – 40m CWID
00:??:00 Next transmission frame – 40m JT65B
00:??:00 Beacon calibrates after each transmission cycle

Notice I didn’t put times for the frames, because I have no idea how long each mode takes. I could sit down with a sharp pencil and a calculator and attempt to work it out, but hey it is just so much easier to actually program the above sequence and measure how long each one takes, and this is what I found.

First, QRSS:

Putting this all together I assembled the following cycle with a duration of less than 20 minutes:
Start Duration Frame / Mode
00:00:00 2 min First transmission frame – 40m WSPR
00:02:00 6 min Next transmission frame – 40m QRSS
00:07:00 8 min Next transmission frame – 40m SlowHell
00:16:00 secs Next transmission frame – 40m CWID
00:17:00 1 min Next transmission frame – 40m JT65B
00:18:00 1 min Beacon calibrates after each transmission cycle
18 minutes cycle time (more or less)
To cut a long story short, if I set my cycle time to 20 minutes I should be able to get through all five frames and have a small safety margin. This is what I finally programmed (with approximate times):

Figure 4: Mode-Hopping with Frequencies
This was a very interesting exercise and it worked out so well. I’m still changing some of the frequencies (e.g. SlowHell) to find locations that are easier to spot, but that is simply fine-tuning to the already working concept.
Should you be interested in obtaining my “Cheat-Sheet” for the above setup, please do not hesitate to contact me and I’ll email you a copy.

73s de ZR6LU Leon Uys from Johannesburg 0825735580