Archive for the 'propagation' Category

Aurora Watch

admin Popularity: 14% [?] September 15th, 2007

There is so much to look at that effects the radio propagation and certainly a lot to learn if you are new at this, but I found this information interesting and wanted to post it. Thanks to Karen [KI4NGX] for the info. She always sends out a ton of really great stuff on space weather and ham radio. 73, KI4WLR

AURORA WATCH: A solar wind stream is due to hit Earth tonight, possibly triggering a mild geomagnetic storm. High latitude sky watchers should be alert for auroras.

NEW MEXICO FIREBALL: On Sept 13th at approximately 3 o’clock in the morning MDT, an extremely bright fireball streaked over New Mexico, “It was terrifying,” says eyewitness Susan K. Burgess. “I was stargazing outside my house near Santa Fe when the landscape started becoming very bright, as if a brilliant full moon was quickly rising from the southwest. The fireball itself [slowly moved] over the house and disintegrated with a great deal of scatter in the northwest sky.”

At the Sandia National Labs in Albuquerque, a Sentinel all-sky video camera captured the fireball in flight:


Click to view the complete movie.

Based on data from the video, the visual magnitude of the fireball was -14.6, about four times brighter than a full Moon!

“The fireball was a pure emerald green, uncomfortably bright to look at,” adds Harald Edens located in the Magdalena Mountains west of Socorro, NM. “The object was disintegrating when I saw it, with pieces parallel-tracking and trailing the fireball. Those smaller pieces had all different colors–most notably red. I think it has been a piece of space junk.”

Amateur radio astronomer Thomas Ashcraft not only photographed the fireball, but also recorded echos of a distant radio station bouncing off the meteor’s ionized trail: movie. “This fireball turned night into day!” he says.

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No DX Today

admin Popularity: 10% [?] September 2nd, 2007

Meteor BurstWell I didn’t make any DX 2 meter contacts working the meteor scatter today but I did learn quite a bit researching information on the meteor scatter, comets, propagation, and even more about a Yaesu FT-221.

I was excited about the prospect of making a meteor scatter contact but didn’t really know much about it. I have posted what I would call my key points below in a top ten list of things learned about meteor scatter. I know several people did make contacts, so I will just keep trying.

First, one important item was that trying to make 2 meter DX contacts are not made on FM, or even AM, but almost always on Single Side Band (SSB), and using the national frequency 144.200 mhz is common, and the Upper Side Band (USB) is normally used in making these type of contacts. The The initial report from ARRL just said 2 meter contact can be made through the normal frequency of 144.200 mhz and I didn’t think anything else about it until an elmer said that was what DXers (or DXing) use for SSB 2 meter contacts.

Luckily, he also had an older Yaesu, the Yaesu FT-221 all mode 2 meter radio, that he graciously let me borrow. This is a classic 2 meter all band radio and it was a thrill to use it over the weekend. I tuned in a few local repeaters to test the receive ability since he said he hadn’t turned it on in 10 years, and with a few flips of the switches I was listening to the normal local traffic we have in this area.

station_ki4wlr_DSC2052.jpg

Second, meteor scatter contacts are very very quick, short contacts, and a lot of the time there is enough propagation time for a CW contact but not enough for a phone contact. A technical NET is our area has some great CW hams and they pointed this out when looking at the time and locations for the meteor scatter.

Third, a dipole would be a good antenna of choice for a DX 2 meter contact. My system setup right now is optimized for a strong 2 meter local contact area, and as such, I use a Diamond, high gain, dual band, verticle antenna at about 50 feet (see gallery images in ham-radio). This is great for local traffic areas but a good verticle V dipole antenna would be great.

So, for my so called top ten list of important things to remember for meteor scatter:

  1. Generally, 2 meter contacts are made using SSB (normally USB) mode
  2. 6 meter and 10 meter might be better if you have the equipment
  3. 2 meter national contact frequency is 144.200
  4. Very quick contacts that last only a few seconds, good for CW, not as easy for phone
  5. If possible, use non-verticle antenna like a dipole or yagi
  6. Know the peak times and plan ahead
  7. Coordinate with a DX friend and plan for a time and frequency to contact ahead of time
  8. Have nice ham friends that let you borrow equipment right at the last second
  9. Don’t forget to ask lots of questions of fellow radio operators
  10. Have fun.

Didn’t make any contacts but had a good time trying. I am sure there are many hams that might read this and know far more than I do about meteor scatter so please feel free to update, correct, or otherwise point out some good information for next time.

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