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Going SOTA /P with WSJT-X


You can of course implement GPS time synching which only needs a GPS receiver and not an internet connection. Out of curiosity I did this and it works.


Tuesday 22nd May 2018 - The Cloud G/SP-015

Having established my first ever FT8 QSO on Sunday evening, I was keen to get out on a summit and really see it working. Before leaving the house, I turned on the Windows tablet and checked how the time was. Back to two seconds out, unfortunately. I downloaded a thing called Dimension 4 which was recommended to me by a member of our contest group, and installed that on the tablet.

Setting up on The Cloud, and the thing was still 2 seconds fast - fine for JT65, most unfine for FT8. I set my Android phone up as a WiFi hotspot and connected the tablet. I had the Time.Is website running on it, and I randomly turned the “set time automatically” button on and off. Or it could have been that Dimension 4 was now up and running. In any case, the clock displaying on WSJT-X was now exactly matching the time on my 60kHz radio-controlled clock - so I was good to go.

Just as I started operating, a chap wandered up and introduced himself. It was Brendon VK4MHZ who I had worked S2H a few weeks ago. I was on The Cloud, while he was on Shutlingsloe across the valley operating for HEMA. “Oh yes, you’re the chap that got kicked out of that programme and had all his logs deleted aren’t you?” he mentioned. Indeed I am, the very same. I had just set up the 20m GP, and Brendon was very interested in that antenna, and gave it a thorough examination.

I initially made five QSOs on FT8, into Turkey, Slovenia, Switzerland, USA and Germany. All well and good, except for the fact that the QSO rate was about 1 every 6 minutes. This was entirely due to my own lack of experience and getting used to the mode and the software.

At this point I decided to have a go on JT65. I made two contacts before almost falling asleep at what now seemed like a dreadfully slow mode! That was enough of that, and back to FT8 I went. I added seven more QSOs, but still at a sluggish pace. I definitely need to learn how to pick my spot better, and properly get used to running WSJT-X on my tablet. Not a bad start though.

Next it was 20m CW, and 8 contacts in 8 minutes as activating life returned to a more familiar pace. I then tried PSK31 but I think my Wolphi-link interface has had it - it certainly wasn’t performing properly. I’m not too mithered about that; I want to get Fldigi going on my tablet anyway, then I can use my shiny new ZLP MiniProSC interface and cables, which are all in good nick.

After packing away the main gear and aerial, I called on the handie and made some QSOs on 2m. It was a lovely extended afternoon activation in the sunshine, and several interesting modes deployed. Many thanks to all chasers worked.

20m CW: 8
20m JT65: 2
20m FT8: 12
2m FM: 5
2m C4FM: 2
Total: 29 QSOs.


Dodgy geezer.


With the greater sensitivity of FT8 compared to CW, it is a natural for QRP SOTA work…only problem is the extra hardware required :frowning: Has anyone done anything about trying to get a system up that will be compatible with RBNHOLE to automatically spot FT stations calling “CQ ST”?


I’ve played a bit with time synchronisation software, though not for this purpose. As I recall, the snag with Dimension 4 is that it is not really a proper NTP daemon; all it does is query a time server periodically and resets the clock to match. (Windows does that by itself anyway; I think Dimension 4 just does it a bit more aggressively.) Proper use of NTP requires continuous tiny adjustments, in effect controlling the frequency of the clock using the external time servers as a long term reference using a damped control loop. The full protocol also makes an honest attempt at estimating the round trip delay to the servers and compensating for it.

The only time sync tool for Windows I am aware of which actually makes an attempt to do this properly is the port of ntpd available from Meinberg:


In effect this software will “learn” the rate at which the system clock drifts and compensate for it even in the temporary absence of network connectivity.

However the real enemy in all of this is the portabilty we want. Obviously taking a machine into a varying environment is not going to do much for clock stability. The other factor is that all of these programs maintain the operating system clock, which is driven by timer interrupts. If the machine ever shuts down, sleeps, hibernates or whatever, these interrupts stop. Time is maintained across these outages by using the CMOS clock, which ticks all the time, but is typically pretty mediocre in resolution and accuracy. Even ntpd does not learn the properties of the CMOS clock, because it does not see it. Any time sync software pretty much has to start its task again when the system wakes up knowing only the approximate time from the CMOS clock. I’m not convinced there is a really good solution for a portable machine if it only has network as a time source.

Martyn M1MAJ


It should be possible, with practice, to manually sync the clock to a local GPS receiver. Practice being the essential word so you can learn your own response delays and the time setting tool on Windows delays.

Lateral thinking here and it may be all wrong… it may be worth suggesting to the WSJT authors team to add time sync facility to the software where it syncs the clock based on the times of when other people are sending FT8 etc. i.e. on reception of an FT8 signal, the software knows to reset the clock mod 15 secs if enabled by the user.


Well something was keeping my tablet clock in sync with UTC. I’ll have to do some elimination tests to properly discover whether it was Dimension 4, Meinberg NTP, Windows or whatever. Certainly, having my smartphone running as a WiFi hotspot is the big enabler.

Main thing will be to improve my knowledge and operating skills for FT8 and get that QSO rate up to where it could be. It’s swilling around at a rate one might expect for JT65 at present!


Working digital modes from a Summit for Sota with a PC/Laptop/tablet Mobile phone whatever doing the work just doesn’t fit well with me. To me it feels worse than having your station connected to your car for power or using a mobile whip connected to your car as an antenna.

I feel it totally goes against what Sota was all about going portable with lightweight gear and making one to one contacts using modes that you do the work. Ie SSB and sending Morse with either a paddle or straight key. Not working stations you can’t even hear with you ear and some electronic device decoding the contact for you.

Not having a go at anyone but think its against the Spirit of what Sota was all about. others may and will have different opinions I’m sure but personally I will never work any mode from a Summit where my ears are not doing the decoding.


John VK6NU


I use nettime (I think it was recomended from the WSJT-X site, but I could be wrong) raerly more that 15mS off!

73 Ed.


That cannot possibly be the case John, as datamodes have been included in the programme from its very inception. It is portable amateur radio, with lightweight gear, making one-to-one contacts and not supported by repeaters, internet etc.

Of course, you can impose additional voluntary rules and restrictions on yourself, and many people do. You can choose to participate datamode-free if you wish, just the same as people choose to participate CW-free, CW-only, VHF-free, VHF-only etc. That’s fine.

But against the intended spirit of SOTA? I doubt that very much; if it is, it has never been written into the rules.


But those modes never existed when Sota started so from a personal view they are not what QRP Amateur Radio is all about.

A 10 year old can get on digital modes after he/she passes their exam and gets a callsign. They could probably work (DXCC)100 countries worked in 2 weeks or a month. They have never picked up a microphone spoke to anyone, never had a CW/morse code contact with anyone and this is amateur radio as its determined at the moment.

But if SOTA MT think that’s a part of Sota, then I guess that they way it falls as they make the Sota rules. To me personally I wont use digital modes as to me it goes against QRP/Portable operation is all about which is what Sota was really all about in the first place. Just my opinion. :slight_smile:

in VK6 I could do with FT8 but won’t ever use it for Sota, I know its a personal choice, but I’m happy with my choice.


John VK6NU


Most digital modes pre-date SOTA by quite a distance!


Yeah the ones the human ear could actually hear like PSK31 and RTTY. :slight_smile:

Stick to CW Tom, its much more rewarding.

Nothing more from me on the topic.

73 John VK6NU


A question from the UK Foundation Licence syllabus and examination:

Q: What is the purpose of the amatuer radio licence?

A: Self-training in wireless telegraphy.

I don’t take this to mean literally only improving my CW while ignoring every other facet of the hobby. I see this as following up on any lines of interest, and developing new skills. The official answer remains in its original historical form, but I believe the spirit and intention of that answer is much broader.

When I started in SOTA, I could do one mode - FM. Through inspiration and support in SOTA, I added SSB and then CW to my repertoire. Then PSK31 and RTTY. Then a little experiment with AM, some PSK63, JT65 and recently, C4FM (Fusion). I’ve now branched into FT8 - and enjoying the challenge.

I do very much enjoy CW and expect that will remain my mode of choice for a long time yet. As someone who has averaged around 150 activations a year for the last 15 years, I expect there will still be bands and modes to suit all tastes in my SOTA activating!

For instance, most of my tinkering with new bands and modes takes replace on my oft-repeated activations of a couple of my local summits (for zero points for me). Later this summer I’ll be off on me travels with M0HGY, and the focus will be on securing the the uniques and the points as quickly as possible. For that then, mainstream bands and modes will be prioritised. Over the course of a year’s activating, you’ll get a bit of everything from me.

The idea of AR is experimentation, development, new technology, innovation etc, not sticking exclusively to the technology of a century ago.

Over my time in SOTA I’ve had complaints of:

Not enough VHF.
Not enough HF.
Not enough FM.
Not enough SSB.
Dislike of JT65.
Dislike of FT8.
Dislike of PSK31.
Not enough Alerts.
Too many Alerts.

It seems it’s true; you really can’t please all of the people, all of the time. Good, because I’m never trying to :wink:


I did rare grid CM79 6 Meter FT8 operation few weeks ago. I used IC-7100, Dell Latitude laptop and two 7.4 V Li-Ion batteries.
Everything feet into 24 L day backpack.
I will try to use the same setup for FT8 SOTA activation.


I do some FT8 at home. I like it ok, but I dont love it because I dont find it all that satisfying. It is a little too scripted, cold, and distant. However, on a terrible band day, some radio is better than no radio.

For SOTA though, the intrigue and challenge of it is not doing the mode. It is doing the mode way the heck up on top of a mountain. It is the challenge of getting a reliable system to work that doesnt weigh a ton and is disconnected from wifi and the world. It is operating in adverse conditions. Does that make FT8 any more interesting? No, not really. But it is all part of the greater, more interesting challenge.


It’s also possible to automatically sync your PC clock to a GPS receiver’s serial output. Notably, most of the HTs with GPS (TH-D72, FT-2DR, etc) include a feature to output the GPS NMEA sentences onto the USB/serial port. Plumb that into the PC and run software that reads the timing messages and syncs your clock. The free app GPS Time is an example, although there are others both paid and free. I have no experience doing this but it Ought To Work™. An HT isn’t required either; standalone GPS receivers on USB are cheap and plentiful, just make sure the GPS chip sends the appropriate NMEA sentence for your time sync app of choice.

The proposal to have WSJT-X offer a self-syncing feature has been floated on the dev mailing list before, to notably muted response. Enterprising folk might be better served just writing such an app themselves. The 13 seconds on/2 seconds off rate of tones is likely regular enough to detect with a small FFT, and the time doesn’t even have to be correct per se, just needs to be snapped to a 15 second boundary with good accuracy to all the signals out there.


It seems to be behaving now as long it’s got a WiFi connection. One of the bits of software is doing its job it seems. I can use my phone as a WiFi hotspot, so we should be OK.

I’m going to wander out later and try some 6m FT8, see what happens. I believe 50.313MHz is the QRG. I know FT8 is unpopular with some SOTA chasers, so I will do some CW as well.

For the 2m chasers, I’ll try to include a bit of 144MHz C4FM as well at some point.


Looks like I will miss you Tom, sat on G/SP-004 as I type this!

Have activated the summit, so will be heading back home soon. Hope to catch you next time. :slightly_smiling_face:



Monday 28th May 2018 - The Cloud G/SP-015

In the end, I ran out of time to do other stuff I wanted to do. I did try a few calls on 2m C4FM and one on 2m FM, but no responses. I didn’t have time to do a bit on the key on 6m, much as I would have liked to.

The 6m FT8 frequency - 50.313MHz - was very busy. The waterfall and received messages window were full of fast-moving activity throughout my time on summit. I would have liked to have tried CW so as to see to what extent this was an opening - or just the possibilities opened up by FT8.

I made only nine QSOs - so still need to get better at operating in this mode. The DXCCs worked were CT, EA, F, GW, I, SP & SV9. So six ATNOs for 6m FT8 :wink:

I’ll probably have another go at 6m FT8 pretty soon, as it looks an easy way to build up a good number of DXCCs on 50MHz.