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Old October 1st 18, 02:18 PM posted to
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Default The great FT8 debate: M0BLFs take

I have casually read the announcement of the upcoming Dxpedition to Montserratÿby three young English hams: M0VFC, M0BLF and M0WUT from November 17 to 23, 2018 and I noticedÿthe link where Dom M0BLFÿexplains the reasons why they won';t use FT8 on this occasion. If you missed his article here it is:

I've been pondering for a while about whether or not I should add my own opinions to the polemic about FT8, the now year-old digital mode that has taken the ham radio world by storm. A few things recently have convinced me that I should, which I'll go into a little later in this short essay.

Me working VK5PO on FT8

First off, a step back: What is FT8? It's the latest in a line of digital modes developed by Joe Taylor K1JT, that permit two-way radio contacts to be made with incredibly weak signals, often below the noise floor. Until last year, most of the modes in this family were used for specialised purposes such as EME (bouncing radio signals off the moon) or meteor scatter. This meant that they were adopted by a small subset of radio amateurs for their specific purpose.

(EDIT:ÿThanks to DG1TAL, who has corrected me:ÿ‘JT65 has been used on HF for quite a few years, even though the dynamic range of RSSI reports was not suitable.'ÿThat's true, but because of the limitations, JT65 still used by relatively few people.)

About a year ago, FT8 came onto the scene. Its main difference over the other modes in the lineage is the speed of an ‘over': reduced from for example 50 seconds in JT65 to just 15 seconds. This made it much more suitable for generalised use, and very quickly FT8 was adopted for general contacts.ÿA post by Clublog author Michael G7VJRÿin January this year shows how exponential the popularity of this mode was in the second-half of 2017; a trend which seems to have continued.

I was certainly part of this band-wagon of FT8 fans. I logged my first FT8 contact on 16th July 2017, and to date I've made 118 QSOs using the mode from home.

Some people have tried to argue that FT8 isn't amateur radio. I disagree. For a hobby founded on experimentation, technical challenge and self-training in all forms of communication, FT8 is the very essence of what amateur radio advances should look like. It's very clever technology with some seriously complex maths behind it, that represents (technically) a significant step forward from what we had before.

I also believe that FT8 has its place in our shacks. One of the biggest threats we have to the hobby is that, particularly in sub-urban environments, noise floors can be very high from consumer electronics. Furthermore, in a globalised world, national regulators appear generally impotent to enforce the regulations that are supposed to avoid pollution of the radio spectrum from poorly-designed equipment. This was one of the reasons for my speedy adoption of FT8. Frankly, from my location on the outskirts of Cambridge, I wouldn't be able to work as far without the support of the weak-signal error correction that's inherent in the mode.

This is all the more important during solar minimum, which I suspect plays a large part in the quick spread of FT8. For the next few years, the stage of the sunspot cycle means that radio wave propagation will be hard, especially on higher HFÿ bands. Having a mode available which allows low signal-to-noise ratio contacts is certainly a help to communication on those bands, which would otherwise be ‘dead'.

The other fantastic thing about FT8 is that it brings, for the first time, objective signal reports to the hobby. We all know that '59' is a nonsense, but in the more ‘manual' modes, we don't have anything better. Using actual, genuine, signal-to-noise measurements for signal reports allows more meaningful comparisons of equipment, antenna performance and propagation research.

However, in recent months a few things have happened, which started to quell my enthusiasm for the mode.

First was one day when I was working from home, doing my day-job. Since the computer was on anyway, I left FT8 running, periodically clicking the ‘Log QSO' button when I saw it on the screen. Operating like this, I managed to make about 25 QSOs during the day without even realising it. None of those contacts were memorable. The computer made them for me, while I worked on other things. Moreover, the formulaic nature of the FT8 exchange (the facts that you have only 13 characters per over, and that changing the text of an over from the defaults can confuse the other operator) means that I felt no connection with those people at all.

You might argue that the same is true in a ‘rubber-stamp' SSB or CW contact. To some extent, yes, but you still have some variability in what the operator has sent, any accents in speech, or quirks of Morse rhythm or spacing. In comparison, FT8 is clinical.

Then, on the GS3PYE/P DXpedition to Islay last month, I became aware of another disadvantage of FT8. 15 second overs may be comparatively fast, but they aren't as fast as a good SSB or CW pileup, and our QSO count for the week suffered as a result. We were well down on even last year, because of the amount of time we'd spent using FT8 on bands that were open.

Similarly, the focus in the community on monitoring the main FT8 spot frequency on each band, means that other contacts seem to be being missed. I know lots of people are pouring over the stats to see whether FT8 activity is ‘new' activity, or to the detriment of other modes. I can only speak from my own anecdotal experience: A couple of weeks ago, I was on a SOTA trip to France, and was eager to make some 6m CW QSOs. There was sufficient sporadic E propagation, and the Reverse Beacon Network heard and spotted my CQs, but in 20 minutes nobody came back to me. Tuning higher on the band, there was just one frequency with signals on it: the 6m FT8 frequency.

Which brings me to another concern: that of spectrum usage. (I'm discounting here the as-yet little-used DXpedition mode in FT8.) On a lot of bands, there is pressure for spectrum used by amateur radio to be reassigned to other, more ‘valuable' uses. Until now, we've been able to demonstrate, particularly during major contests, how busy our spectrum can become, which has helped in the argument to keep the range of frequencies we current have. If we all start making our contacts in the 3kHz bandwidth above a single spot frequency, we may be doing the hobby some significant harm.

What's the solution? As I said above, I fully support the rationale behind FT8, and particularly its use in high noise areas, and on bands where propagation is difficult. Especially if it can capture and encourage the imagination of a newcomer, or someone who has been inactive in the hobby for a while, we must celebrate and support its use.

What I'd really like is, when you start receiving signal reports with positive numbers of dB, the software should remind you to switch off and try other modes instead, as the band is sufficiently open. I doubt we'll see that, however, so it's up to us as operators to consider the wider effects of the mode, and when/whether it is appropriate to use.

I'm already limiting my use of FT8 at home: this Sporadic E season on 6m, I have deliberately only been using CW, not FT8, and for a forthcoming (as yet un-announced) DXpedition, we are seriously considering not taking any FT8 equipment.

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