Audio of Eric from 3B9C and my almost QSO: kkn.net/n6tr/160/3b7cQSO.mp3 <https://www.kkn.net/n6tr/160/3b7cQSO.mp3>
On Fri, Nov 22, 2024 at 1:21 PM Eric Scace K3NA <[email protected]> wrote: > 3B9C — yes, I was there. But I don’t recall working 160m SSB, just CW. I > did work a couple of long-path QSOs with the west coast on top band (west > coast sunrise, 3B9 sunset). > > It was interesting to see the delay from when 160m closed in the morning… > to 80m CW closing… and then finally 75m SSB. The 10%+ difference in > frequency between 80m CW and 75m SSB was obvious. > > > On Nov 22, 2024, at 06:44, [email protected] wrote: > > > > > > Hi Eric, > > > > Thank you for explaining that! I always wondered how it was possible > that I worked such a loud 3B9C (honest S9) on 4/12/04 at 0012z on 160 SSB! > Were you on that DXpedition? > > > > I also wonder if this phenomenon of ducting would explain my JA qso's on > 160 which were made 1st call through a pileup of W4 /W9 shortly after dawn > some years ago? The likelihood of my ever beating out a W4 or W9 to JA on > 160 is ZERO, so some rare and unusual propagation effect was at work. > > > > 73 > > > > Bob, KQ2M > > > > > > > > > > On 2024-11-21 21:47, Eric Scace K3NA wrote: > >> Hi Ron — > >> See attached image of the twilight zones at 00:40Z today. You will > see that 3B9 is in the middle (nautical) twilight zone band… and the > twilight zones cross North America. > >> Having worked this path myself from 3B9, I can testify to how cool it > is. Ducting explains part of why the signal was so loud when you heard them > — ducts are very low loss conduits for signals at the ducting frequency > range. But escaping from a duct requires the signal to encounter some > less-ionized part of the floor of the duct, so that the signal can continue > down toward the earth’s surface. And the exit point still has some > refraction, so the signal may exit the duct at a very shallow angle and > travel a long way before it reaches the surface. > >> These thin spots are indeed spotty, transient, and move around. > >> When I was on 3B9, clumps of geographically-adjacent stations would > get worked — a spot corresponding to a weak spot in the duct. Some clumps > were clearly connected to each other by an added ionospheric hop in the > normal way. We could plot this clumps over time and see them move along > with the terminator… but eventually (minutes or tens of minutes) a > particular “leak” would close up. Maybe we had several “leaks” at one time, > working different spots in North America… and sometimes no leaks at all. > >> So yes — spotlight propagation. > >> This emphasizes why it’s important for a DXpedition to be on top band > every night. Some nights will have no ducts. Others with have leaky ducts — > but the leaks will only illuminate certain patches of North America (in > this case)… and on another night different patches of North America. To > give everyone a chance, one has to be on every night. And for the person > chasing the DX, one has to be listening every night until a leak/spot > favors that person’s location. > >> And then, as you experienced, it’s super easy to work each other > through that low-loss path. > >> — Eric K3NA > >>> On Nov 21, 2024, at 19:37, Ron Spencer via Topband < > [email protected]> wrote: > >>> Tonight (11/21) around 0040Z I saw a signal pop up on the panadapter. > Tuned to it and its 3B9/M0CFW calling CQ. 15dB or more above my noise > floor. I couldn't believe how solid and loud they were. After amp came on > line I called and worked them. During the wait time I did a quick internet > search to see if is indeed a real station. Yep. > >>> What amazed me, and still does, is absolutely NO rbn or packet spots > during the at least 5 minutes they were on. And no other callers. Even > after I spotted them on packet and the kst chat page. > >>> I have no explanation for this. Why no rbn spots? Why no other callers > when they were very solid for almost the whole time they were calling CQ? > Was this an example of very small spot light prop? There were others on so > its not like no one was tuning the band. Baffling. > >>> Below is a screen shot of their signal. they are in the red area. > Received on my homebrew 8 antenna circle array with no preamp. > >>> Perhaps someone out there has an explanation. > >>> Ron > >>> N4XD > >>> Sent using https://www.zoho.com/mail/ > >>> _________________ > >>> Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > >> _________________ > >> Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > > > _________________ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
