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HOWTO: NOAA Weather Satellites
radio : by Tommy - August 7th 2013, 11:31AM
radio
Most people are aware that every day weather satellites pass overhead to get a glimpse of the nation's weather patterns. Many people, especially those outside the ham radio community, are unaware that the signals these NOAA weather satellites transmit are readily accessible with a minimum amount of equipment. These satellites use a technology known as APT, or Automatic Picture Transmission. NOAA-19 is perhaps the easiest APT satellite to receive because it provides the best, strongest signal for visual satellite imagery. Because of this, we'll focus on NOAA-19 for this post.

Hardware
All you really need to receive the satellite's signal is a radio receiver like an old police scanner (found at thrift stores) or a simple 2m ham radio handitalkie (like the Baofeng UV5R). An external antenna is usually better, but not a requirement for casual reception of the image. Other than the radio, the only other pieces are a computer with sound input and an audio cable (to get the audio out from the radio to the input on the computer).
If you would like to get the best images possible from every pass of the satellite, use an outdoor antenna connected to your radio. Discone antennas for scanners work well, as will any 2m amateur radio antenna. These antennas do suffer from "fades" where the gain of the antenna is weakest. To minimize these anomalies, eggbeater antennas or the very common quadrifilar helical antenna are used by serious hobbyists and weather professionals.

Software
Once you have the required hardware, download the free WxToImg software which is available for Windows, Mac and Linux. There are other features and enhancements to the software if you upgrade, but it's still not a requirement.
Once the program installs, the first time you start the program you will be prompted to enter your Latitude and Longitude.

Continue reading...

tags: radio noaa-19 wx satellite howto

( Comments : 1 | Full article )

 
HOWTO: Intro to Twitter
neodux : by Tommy - February 16th 2012, 11:40AM
neodux
For anyone online you've no doubt heard that social media is defined by sites like Reddit, Facebook and Twitter. A lot of people talk about Twitter, but a vast majority of people don't know how to use Twitter. I must admit that I've had an account for years but wrote it off because it seemed so limited. The power of Twitter is not found in the brevity of the "tweets" (posts that users make on Twitter), but in the ability to monitor tweets of others.

Flow of news
In the traditional model of news aggregation, you would turn on the TV or radio, open a newspaper or seek a sole source of information. That organization would have already done the leg work of finding news, picking out what they thought the majority of their viewers/listeners/readers would find appealing and put that news out there. With the introduction of "social media", suddenly people can discern for themselves what is important. The early days of Digg brought this idea to reality and reddit took over where Digg left off. The users were now in control of the information, not the producer, publisher or editor. I'm not saying that Twitter affords this ability, but it allows you to search for items that have been flagged with certain key terms. In Twitter parlance, this flag is known as a hashtag. Until I understood hashtags, I didn't "get" Twitter - now I do.

#Hashtags - The key to Twitter
Hashtags allow you to share information that you tweet with others within a community of individuals that are, themselves, looking for information relevant to a subject. The same way that you search for things with a search engine through key words, you can also hunt for tweets with a hashtag.
I deal a lot with Education Technology, so when I'm looking for news, links and information related to Education Technology, I'll look at the Twitter hashtag #edtech.

Continue reading...

tags: twitter howto

( Comments : 0 | Full article )

 
HOWTO: Getting Started with CW
radio : by Tommy - October 18th 2011, 05:50PM
radio
It's been a year since my post about Morse Code: Brief History, and I figure I might as well shed some light on how to get started operating with Morse Code. Since the Morse code requirement for ham radio was lifted in 2007, the number of amateurs getting their HF privileges has grown substantially, but with the "repeal" of code, entry level Technicians are granted privileges in certain portions of the bands. Most commonly, Technicians can operate SSB in the 10m band, but can also operate CW, or Morse Code, in 80m, 40m, 15m, and 10m. So, if you're a ham, you already have privileges to operate CW - you just need to learn where to start.

Learning the Code
For starters, you will need to learn Morse Code, one way or another. (duh.) While it may not be the universally agreed upon best way, I learned Morse Code through the Code Quick program. It really is an easy way to learn and quickly remember the code. There are countless gimmicks and "5 Minute Ab"-type programs that try to rush you through the learning process as fast as humanly possible, but few are ever successful. You just can't hurry the learning process. The downside of the CodeQuick method is not immediately known until you're trying to copy signals that are faster and faster. Once you hit about 10wpm, the CodeQuick lessons that you've used as a crutch finally become a hindrance and make copying code faster more difficult. The big plus is how quickly you'll learn the code in relatively enjoyable lessons compared to other methods.
Another alternative to learning the code is one of dozens of Koch method trainers. The Koch method, and most others, ram the code into your head seemingly through brute force.

Continue reading...

tags: ham radio cw morse code howto

( Comments : 0 | Full article )

 
HOWTO: ISS Viewing
outdoors : by Tommy - October 5th 2011, 09:08PM
outdoors
The fact that there's a space station orbiting above the globe right now has become somewhat passe in pop culture. Not many people are truly wowed at the news of it. Within seconds, a few clicks of a mouse will take you to hundreds of pictures and videos of the International Space Station; but did you know you can see the space station yourself? No binoculars or telescopes needed! I figured I would write up a HOWTO for the uninitiated. It isn't hard, it just takes a little know how.

For starters, you need to know a few terms used when talking about satellites (the ISS is a satellite of the planet Earth).

Azimuth
The first term when dealing with satellites is azimuth. Azimuth is a technical term that means the same thing as heading, bearing or direction. Most people are comfortable with the cardinal directions North, South, East and West. The cardinal directions are fine for general directions, but to know exactly where something is we need to be more specific. When dealing with an azimuth, a number of degrees is stated. 0 is North, 90 is East, 180 is South, 270 is West, and on around to North again. Kinda get the picture? It's a full circle divided into 360 degrees. (Also note, there's technically no such thing as 360 when dealing with Azimuth, because 360 would be the same as North, but that's already 0.)

Altitude
It's not entirely what you think. Sure altitude means height, but we're not talking in feet or meters here. Remember, we're dealing with observational angles here, so knowing how high something is is of little consequence to us. Altitude in astronomy means "angle above the horizon". Altitude is expressed in degrees, just like azimuth. 0 is at the horizon, 90 is straight up. 45, you guessed it, is right in the middle.

Continue reading...

tags: iss space astronomy satellite howto

( Comments : 1 | Full article )

 
HOWTO: Working FM Ham Satellites
radio : by Tommy - January 22nd 2011, 03:37PM
radio
A local ham recently asked me the best way to talk on ham radio satellites using what he already has on hand. It doesn't take much, although some more specialized equipment does make it much easier, but the point is - you don't need much beyond what you may already own if you have a basic VHF/UHF station. The following is my email to him:

Which birds to target and how to track them
"The best satellites to start with are AO-27, AO-Echo and SaudiSat-1C. (Satellites go by different names depending on where you're getting your info.)

I usually direct people to Heavens-Above to get the latest pass information. The exact time and angle of each pass varies from day to day, so you either need tracking software or a website to tell you when the next pass is over your location. With Heavens Above, you need to enter your longitude and latitude, so it can figure out the information for you.

I've put in the longitude and latitude in for my QTH here in Longview on this link:
http://www.heavens-above.com/main.aspx?Lat=32.5560&Lng=-94.7474&Alt=365&Loc=N5DUX&TZ=CST
(change the location by editing the link or click on the link under Configuration at the top of the page)

When you go to the website, you'll be shown a lot of different links. For our purposes, we're interested in "Radio Amateur Satellites". Click on that link.

Now you'll be presented a table of all the various satellites that Heavens Above is tracking. I usually find the satellites I'm interested in working, then look over at the "maximum elevation" - this is how high in the sky the "bird" will get. Generally the higher the pass, the better chance of hitting the satellite you'll have. If all you're using is a vertical, 45-degree passes will give you a good shot. But anything greater than 30-degrees should be doable.

Continue reading...

tags: satellite ham radio intro howto

( Comments : 2 | Full article )

 
mod_rewrite: URL modification
programming : by Corey - October 2nd 2010, 07:22AM
programming
To say that there is extensive documentation on Apache and its various plugins, including mod_rewrite, is to grossly understate the term. Documentation is voluminous to the point of beginning to wonder if the various authors had a combined total of more than five dates with actual girls in the history of their lives.

Disgruntled, then, was I to discover that on the entirety of the Internet, there was no documentation surrounding what I needed to accomplish. I've since come to realize that this is likely due to the obscurity of the issue or the availability of other commonly known tools to accomplish the task I had before me.

That task: Rewriting and redirecting a URL from my local environment using Apache and mod_rewrite.

Without delving into specifics, I needed to take an HTTP request generated by a page viewed in my browser and direct that request to another location, including a change of domain.

Now, the more seasoned among you may resolve that the very purpose of mod_alias is to perform this task. However, just because I'm a glutton for punishment, in this particular case, I also need to change the value of a query string parameter in the URL having its domain changed. Gaze upon the domain of mod_rewrite, ye mighty, and despair.

While mod_alias is designed to handle the translation of domains, mod_rewrite is designed to handle that and query string parameters (as well as a bunch of other stuff that I have no idea about). Before we can start directing URLs to and fro, we must first setup Apache.

I'll not regale the reader with the riveting tale of that process as it is rather well (and usefully) documented. The mod_rewrite module must be included in httpd.conf and the Apache instance must be configured to run as 127.0.0.1 on port 80. Do be wary of configuring the server value as localhost because sometimes the value does not translate, especially in Windows.

Continue reading...

tags: Apache mod_rewrite URL modification redirection cake pie howto

( Comments : 1 | Full article )

 

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