Aug 29
Recently I came to the digital modes (again) on 6m, after I had seen in DX cluster entries, that activity had increased significantly. Here is something on my impressions.

You are invited to read and to comment on this item here and tell us about your impressions.
JT65a and JT9H fast
This is especially the case with JT65A, where I literally received Japan in the first try of this mode for Sporadic E end of June this year. I had successfully done some listening to EME signals on the band before. Since then I have "seen" several US west coast stations even when no opening was spotted at all. I contacted all these stations and all were active exactly at those times. It looks like that there is much more possible on the 6m band. On one hand we see the much enhanced sensitivity but on the other hand it is s-l-o-w. You win one thing but you have to sacrifice somewhere.
Others recommended to me to use JT9H fast mode with 15 secs of turnover for DX operation. It seems to work fine in shortlived "openings" or better bursts. I have tried it in some tests where JT65a worked easily but - for me - this JT9H fast is rather on the edge then. I would better compare it to JT6M where JT9H seems to be a bit ahead due to the error correction. I am not convinced that this mode works good for those above mentioned "low-level" openings.
QRA64A or JT65A
JT65A works fine and is well established. Now I made first tests with QRA64A (what are the differences to the submodes?) are encouraging. I have seen decodes at -32dB down to -40dB. Nothing is heard then or seen on screen. Due to the error correction this cannot be a "fake signal". I am indeed very impressed with it. But - it is only a "feeling" - it seems to be less robust against fading than JT65A.
JT6M or ISCAT
After a good number of extended testing in QSOs I prefer ISCAT, which definitely worked better on Meteorscatter, but the community seems to stay with JT6M. I would like to compare to JT9H-fast as well soon, as I have seen a lot of meteor bursts with good decodes.
FSK441
This fast mode which is commonly used on 2m worked extraordinary well on 6m. When I made a contact my counterpart was always as well surprised as myself. I made QSOs within two minutes.

Now by mid of August '16 where the Sporadic E season is almost over we hopefully can use the winter's time for extensively test all the modes and softwares available.

Posted by Christoph Petermann


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© Christoph Petermann DF9CY - 2009