6 Meter Season Wrap-up for 2019

We are now into 6 meter withdrawal season. This is the time of year when Es (sporadic E) openings rapidly decline in number and distance yet aficionados cannot quite let go. All I hear now on FT8 is endless CQing from those within direct or tropospheric propagation (within ~500 km). Although there is still some DX to be found if you are patient the season is effectively at an end.

This is a good time to reflect on my accomplishments this season and what I've learned. I did a similar season end report last year.

DX

Purple is my favourite colour

I ended last year with 56 DXCC countries on 6 meters using FT8. I tally countries separately from other modes to track my progress. Official counting methods mean little to me since I do not chase DXCC awards. As I write this I have worked 15 more countries this season for a total of 71 DXCC countries on 6 meter FT8. I don't believe there are any countries I've worked the last few years on CW and SSB but not on FT8.

I heard many more countries than I worked. That's the nature of 6 meter propagation. Of note I worked Japan for the very first time on 6 meters, using any mode. These QSOs were my first with Asia. With respects to continents only Oceania still eludes me. I heard several Hawaii call signs this year but all were in the continental US. American call sign practices can be frustrating to the DXer. I know the path exists since several hams in this corner of the continent worked Hawaii this year.

In my season's end article last year I noted that I worked 40 European stations on August 4 during an amazing multi-hour opening. Perhaps more amazing is that I broke that mark this year, working 43 Europeans on July 20. My European distance record now extends to Ukraine. Even so I have heard but failed to work many European countries such as OH, LX, 9H, LZ, YO among others.

I was unlucky with African openings apart from adding CN and EA9. I heard 5T5PA a few times, though very weakly and never workable. Better was 6W1TA who had a fine strong signal for almost 2 hours one day. In this instance I caught the opening near its end and failed to make it through the large North American pile up.

Looking south I worked HC5VF for a new one. CP1GJ was heard but not worked. Many stations were worked in northern South American and Caribbean. One that was active but not snagged was P41E.

My final country for the season was CY9C. In this case I got lucky since many others in this region had difficulty despite the relatively easy single hop path. You win some and you lose some. It would be no fun if every station heard is worked.

50.323 MHz

What seemed to be a great idea to move intercontinental DX activity to its own FT8 window is not working out. There was little to be found there this year. I did QSY to the DX window when domestic contest activity crowded me away from 50.313 MHz but with no success. The DXers, here and abroad, wouldn't move even when the QRM became overwhelming.

CW and SSB

The digi-averse die hards are still on conventional modes. The only significant operating I did on CW and SSB was to use those modes exclusively during the ARRL June VHF contest. Unlike my experience in 2018 this year I had far better success. With only a little effort I managed well over 100 contacts, reaching as far as the west coast. There are still signs of life at the low end of the band!

Despite my almost 100% focus on FT8 for DXing I have not used it in a contest. Perhaps I never will, but you never know. It's too slow and mechanical to hold my interest.

FT4

I have yet to use FT4, restricting myself to occasional monitoring. The 6 meter window is 50.318 MHz. It is certainly fast enough to interest me but I don't know if it'll catch on for DX work. Certainly it has promising attributes for 6 meter DXing. Maybe I'll try it next year.

Decoding sensitivity

There is an ongoing debate regarding FT8 decoding success rate between WSJT-X and alternative software branches, in particular JTDX. This may very well be true. What gives me pause is a few of the methods JTDX uses: correlation to known or expected messages and correlation to a data base of known active calls.

I am still thinking about whether this is a good idea. There is a fuzzy line between viable decoding and guessing, and I am ethically opposed to the latter. Even when I use Super Check Partial (SCP) during contests I always request a repeat or confirmation of the call.

Until now I have been happy to do no more than tweak upward the aggressiveness of WSJT-X decoding, yet even it does a bit of guessing. Where should the line be drawn? I don't know. As time permits I will download and experiment with JTDX on HF, listening only, to learn what it can do and how I feel about it. In the 2020 sporadic E season I will likely run higher power and I can expect more weak callers and therefore have greater need for decoding sensitivity.

Improvement is possible beyond the software. I have altered how I set up my rig and computer to better match the dynamic range of the receiver and sound card ADC. While preliminary results are ambiguous it looks promising. I may have more to say about this if I learn something of substance.

It is unfortunate that WSJT-X calculation of signal reports is not usable for determining signal levels, SNR or receive performance since it is relative to other signals and noise within the pass band. I only learned this recently. It explains some bizarre disparities between received and sent signal reports that I've witnessed.

Transmit quality

There is more activity on 50.313 MHz than ever before. Getting on is easy since every modern transceiver has 6 meters and many HF amplifiers include 6 meters. If you use RTTY or other data modes (or you do SSB contesting, like I do) you already have the required audio connections to your computer.

The trend may continue for the next two years until the solar flux edges upward and thoughts return to HF. I may be responsible in my own small way by encouraging local activity (FN25 and adjacent grids) during several talks I gave to local clubs last winter.

Unfortunately it is all too easy to transmit a dirty FT8 signal and its incidence is increasing in proportion to rising activity. Monitoring your own signal quality isn't easy and few bother to make the effort to do so. Most rely on recommended practices but without feedback don't realize when they've done it wrong.

I got more serious about it this year. With the help of a buddy we transmitted back and forth while tweaking our rigs to see what works best. I am now reasonably confident that my signal is clean. Over the winter I will build a test system so that I can monitor and make adjustments on my own. Perhaps I'll write it up if it looks to be useful to others.

The adjacent screen capture shows an FT8 signal with adjacent images that are often decoded. These are not harmonics. The DSP and equalization circuits in modern transmitters create novel difficulties. These images are present on far more FT8 signals than is good for peaceful coexistence. I get them on my own signal under some conditions and I want to make further improvements.

W9MDB has written a document on setting up your transmitter that looks quite good to me and explains a few peculiarities I've run into. Some surely need the lesson since there are too many signals far worse than is seen in the spectrogram above.

Improving QSO throughput

One of my objectives this year was to improve the number of QSOs I can squeeze into a shorter time. The key to this is understanding the software in greater depth and making liberal use of auto sequence features. The difficulty is understanding what auto sequence does in the critical crossover between one QSO and the next.

I have had good success once I let the software free to do what it thinks is best. It does always work out, and in those instances you simply need to be paying close attention and quickly alter the message or the station you are responding to. In short DX openings, with all their QSB, it is possible to interleave QSOs when one is interrupted by propagation or QRM yet be able to complete it a minute or two later.

There is much more to be said on the subject so I won't dwell on the topic now. I believe it is worthy of its own article. There is always more to learn about the subject and it is possible that many readers will benefit from knowing more, even veterans of digital modes.

Looking forward

As I've said before it is very likely that I'll have a 6 meter capable kilowatt amplifier next year. That is perhaps the biggest change I am planning for the near future. Once my HF antenna farming matures I will pay more attention to VHF. This includes an improved antenna of some kind and antennas for 2 meters and 70 cm. That's the upper limit of my interest.

With regard to other digital modes I have ventured back into MSK144 for the Perseid meteors. I haven't worked much, just playing with it to get more experience. Meteor scatter is something that interests me more for 2 meter use; on 6 meters the distance is easily spanned using more common ionospheric propagation modes.

Of more immediate interest is HF. Now that the peak sporadic E season is over there are antennas and towers to build and get operational for the fall and winter season. It also severs an inconvenient and invisible tether to the shack that keeps me from antenna work.