Friday 15 July 2016

Growing 6m JT65 Activity

image courtesy:
This past week, most of my 6m time has been spent monitoring or working JT65A mode stations, up the band a bit from my usual hangout around 50.100MHz. My main interest has always been CW but for some reason, and much to my surprise, the small sliver of JT spectrum space above 50.276MHz seems to be much 'busier' than the lower end of the band!

On several occasions this week, I have heard or worked dozens of others on JT mode while the bottom end of the band appears void of signals. Thursday morning was a good example, with several contacts down into the southeastern 'EM' grids on JT mode while seeing no reports of similar contacts being made on CW or SSB from my region.

This summer, there appears to be much more interest in 6m JT65 than ever before, as I see many familiar CW operators up the band on digital. There is no doubt that JT65's ability to dig deep into the atmospheric band noise and decode signals too weak to be heard on CW, provides an advantage when conditions are marginal. Perhaps this alone explains why I see such a difference between the two segments of the band. This is when JT65 really shines as it is primarily a weak-signal mode.

When the band really opens up however, things are different ... things can get messy pretty fast when the JT65 band fills-up with S9+ signals! Under these conditions, moving well away from the crowd is often better than trying to fight overlapping signals, often made worse by S9++ signals in your own grid, transmitting on the opposite sequence. In this respect, the JT65 segment is like a wider version of the 50.125MHz calling frequency ... the one spot in the conventional mode section of the band where anything goes ... the wild west of 6m.

Dead Band Spots - courtesy:

During one particularly noteworthy period of no action in the lower part of the band, JT65 signals were either copied or exchanged with CO8, V31, TG9, KP4 and XE. Many of these signals were heard for several hours, making the difference even more striking.

Perhaps having all of the JT signals crammed into a 2kHz sliver just makes it seem busier but the mode is certainly gaining steam. Now actually working guys on JT65 is akin to watching paint dry, as its weak-signal sensitivity comes at the expense of time ... the same information that could be sent on CW in 10 seconds, requires a full minute. A complete QSO takes a minimum of four minutes and the 13-character message buffer does not exactly encourage much conversation, other than calls, signal reports, grid squares and 'RRs'. All the same, calling CQ and waiting for the telltale signs of a reply to appear on the scrolling waterfall is somewhat mesmerizing, not unlike an addictive video game of sorts ... just one more CQ!

Will I abandon the CW end of the band? Never ... but having another mode to play with on the magic band is proving to be much more interesting than listening to the usual din of white noise, waiting for the band to 'really' open.

You can read more about JT65 and download the free software, WSJT-X, here.

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