When I switched to 2m FT8 last night I had a horrendous noise band in the middle of the passband. It was also there on 6m. I feared this was something external (maybe a new TV in the neighbourhood), so some investigation was needed.
Although it was still there in the morning I was still receiving signals. To cut a long story short, it totally went when I turned off NAR on my FT817ND. It was not there anywhere on 2m USB (which of course uses the wide setting). It is now set with NAR turned off, as it was originally. Not quite sure how this got turned on, but WSJT-X clearly did not like it!
Best DX spotted on 2m FT8 RX is S57LM (1239km) at a cracking +5dB S/N. Not bad with my big-wheel horizontal omni antenna. Signal reports suggest a mixture of tropo and aircraft reflections.
UPDATE 0939z: 8 stations in 5 countries spotted since last night. on 2m FT8 RX. Even my brief CQ call on 2m FT8 got a spot from 194km, despite just 2.5W to the horizontal omni antenna.
UPDATE 1305z: 17 stations in 7 countries, so far, on 2m FT8 RX today.
Could it be the ceramic IF filter becoming noisy ?
ReplyDeletehttp://ahrdf.net/forum/thread-44.html
http://sv8ym.blogspot.com/2010/07/mysterious-case-of-withering-filters.html