August Meteor shower
- I've been looking forward to the August, Perseids, shower but just realized that I'll have relatives visiting the weekend of August 13th.
What's the "shape" of this shower? IE, will there (likely) be more roxs several days prior to the peak or the days after?
I would like to plan a trip to CM86.
- Virgo is a great site that I use regularly, especially when major showers are approaching.One critical shower parameter NOT given by Virgo, however, is the mean Velocity (in km/s) of the rocks in that shower, which is a function of the astronomical dynamics that exist between Earth and the incoming meteor stream. The data is available on a variety of meteor websites, like the American Meteor Society site at http://www.amsmeteors.org/2010/12/2011-meteor-shower-list/ .Meteor shower velocities range over approximately a 2:1 ratio, with the always-reliable December Geminids being one of the slowest at 35.0 km/s and the Perseids being one of the fastest at 60.5 km/s. (The Leonids, Orionids, and Eta Aquarids are all slightly faster than the Perseids, with speeds between 60 and 70 km/s.) Virgo should add this parameter to its table for all meteor showers.What’s the big deal with velocity? Basically, the faster a meteor is going when it starts to hit the gradually-thickening atmosphere of Earth, the higher above Earth it will be when it starts to ablate and ionize. Greater height means longer propagation paths on Earth and sometimes new distance records! While it’s possible to make a LOT of contacts during the Geminids, it’s easier to make that one special 1,300- or 1,400-mile contact during the Perseids, the Eta Aquarids, or one of the other “high-velocity” showers — providing, of course, that the shower is productive of rocks! :-) Some of these high-velocity showers have been spectacularly unproductive in recent years, as was noted by Andras.73,Bill W5WVO
Just take a look at
In Table 5 you can see:
where August 13th is the peak day of the shower.
Perseids (PER)* Jul 17 - Aug 24 Aug 13
During the recent years Perseids were not so usable as before.
I shoud say, the best shower is the Geminids in December.
Above all, it often "covered" by Es -from the radio operators' point of view.
Here in Europe we use a website with a software named Virgo written by DL1DBC. It shows the "visible2 part of their orbit (Perseids are circumpolar...) and the optimum directions.
Just visit: http://www.dl1dbc.net/Meteorscatter/
gl de ha6nn
- I recently acquired an Ameritron AL-80 amp that was converted to 6 meters. It uses a single 3-500z tube.The amp has a --single-- fan inside, and force cools the tube. From what I have read, this amp is identical to the Heath SB-1000.What cooling mods have you guys made (if any) to similar tube amps, for WSJT work? I have a nice and loud (and very fast) 110v fan similar to the one inside, that I can place on the outside where the exhaust holes are, but I was also thinking of getting a larger computer type 12v fan, and place it inside right next to the tube (if there is enough clearance), and having it exhaust the air out.I know these 3-500z's are very forgiving, but I was waiting for this weekend's CQ VHF contest to pass, before I 'sacrifice' it to WSJT.