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HOWTO: Configure Hamlib for Linux Hams - Part 1
radio : by Tommy - December 2nd 2013, 8:11PM
radio
Linux and ham radio, where two of the geek worlds collide. Fortunately, with so many geeks involved in both pursuits, a lot of great tools have emerged. Unfortunately, documentation on how to configure some of it was hard to come by. (At least, it seemed that way to me.) Here, I hope to layout as quickly and easily as possible the steps required for other hams to configure hamlib on their linux computers. I'm going to assume you're running a modern version of linux and have a USB connection to your radio and/or rotator.

What is Hamlib?
First of all, Hamlib is a set of ham radio control libraries that allows amateur radio operators to control their radio and antenna rotators via their computer. Hamlib abstracts many device-specific control issues from application developers, allowing for a more robust user experience across several programs. Prior to hamlib, there were several different tools and libraries. None of these tools provided a common API for programmers to interface. As a result, the application landscape was fragmented and functionality suffered. Now, with hamlib, programmers can utilize hamlib to interact with a whole range of devices.

Interface
To use hamlib, you must first have a computer interface cable from your radio to your computer. Without this, everything else here is pretty useless. If you don't have a cable yet, look on eBay for cables tailored to your radio. (It's where I found mine.)
My radio is a Yaesu FT-847 which has a DB9 serial port for CAT computer control. To interface with my computer, I use a cheap USB-to-serial adapter - nothing special. My antenna rotator is a Yaesu FT-5500 with the brilliantly simple WA8SME Satellite Tracker Interface from the ARRL.

USB, Linux and udev
Most modern distributions of Linux include a subsystem to handle when USB devices are inserted.

Continue reading...

tags: ham radio hamlib linux satellite

( Comments : 0 | Full article )

 
Higher Ed Enrollment Database
news : by Tommy - September 3rd 2013, 11:45PM
news
This is something I thought today during a meeting...

I recently learned we have had several students not report *all* institutions they've attended before. (Ex: One student "forgot" to mention they had taken courses with Univ of Phoenix for ~70hrs and stopped attending. Univ of Phoenix is holding that student's transcript until they settle up on their bill. [Transcripts are the one thing a school can hold over a student for failure to pay.] It came to light when the student's Financial Aid was processing...)
School's usually require this because prior scholastic work is taken into consideration when placing the student in courses, academic standing, etc. and ensures a students will make good on their financial obligations - like a gentlemen's agreement among institutions. I asked in our Registrar's office what happens if a student doesn't divulge all schools they've attended, "What's the worst that could happen to them?" "It could get them suspended from our school." In the grand scheme of things, so what? They could move down the road to another school and take classes there. It would be a huge headache for the student, but a driven and motivated student could navigate the system and get their degree one way or another from some institution. (especially from certain schools that are willing to do anything to get money and could care less about the other schools down the road...)

So. What's the big deal? The trouble is Financial Aid fraud.
Unscrupulous individuals will solicit the school for financial aid, scholarships, grants, etc. in hopes the grants and loan money comes to them directly and/or any overage in scholarship/grant money gets sent to them directly, all the while never intending to *actually* take classes. Before any financial aid is disbursed, the student will usually sign a short-term loan with the school to cover the courses in the meantime.

Continue reading...

tags: highered college education

( Comments : 0 | Full article )

 
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 )

 
RTL Software Defined Radio
hardware : by Tommy - May 9th 2013, 10:56PM
hardware
Last week I got my newest toy in. It's a USB DVB RTL Receiver featuring the Realtek chipset beloved by radio enthusiasts. The chip functions by receiving radio signals and converting them to audio streams which the computer can decode/demodulate using software. The software tells the chip what frequency to tune to, and demodulates the signal. This concept is known as a Software Defined Radio or SDR for short.

The Realtek is cheap and agile enough to tune a wide range of frequencies (52 MHz-2200 MHz). Thanks to free (as in beer) software like SDRSharp, the "work" of setting up this complex sounding setup is almost trivial. (Especially if you use the install script in the downloads section of SDRSharp. Other websites can show you how to setup a trunking radio scanner for police/fire/EMS in your area. [So long as your local fire responders don't use a trunked P25 Phase II system])

If you're looking to get started, check out this USB DVB Dongle (any RTL2832U receiver should work). I would also recommend getting an antenna pigtail so you can use a bigger/better antenna for whatever frequencies you want to receive.

tags: radio sdr rtl

( Comments : 1 | Full article )

 
Ham Radio PDF Archive
radio : by Tommy - March 26th 2013, 04:11PM
radio
The other day I went looking for an old issue of the once-free publication WorldRadio Online, but had trouble finding all the issues in a single repository. I decided to make myself one once I found all the files. So here it is: www.n5dux.com/ham/pubs

WorldRadio used to be a very low key, cheap publication about amateur radio. The kits and homebrew articles were worth a look. WorldRadio had a small following but when the much larger CQ magazine offered to buy-out WorldRadio, the owners of WorldRadio gave in. CQ has far more advertising dollars to support their publications (CQ, CQ-VHF and PopComm) - for them, it's a business wrapped around a hobby. WorldRadio was more of a hobby wrapped around a hobby.

So CQ Magazine bought the small WorldRadio, moved their "lifetime subscription" members to a one or two year CQ magazine subscription (crummy deal) and made WorldRadio into a free, online-only publication titled WorldRadio Online. (A move that jilted many of the older, not-quite-so-tech-savvy readership.) Many of the longtime readers said it was the end of WorldRadio, some said it was the start of online publications for ham radio. Both were right. WorldRadio Online was a great monthly treat because it was free. The transition to online was made easier in that the reader wasn't having to pay for it. The content got watered down somewhat as CQ wasn't making much money on the project, but you get what you pay for: no complaints. Still, longtime readers still said the end was near for WorldRadio. In October 2011, they were proven more correct. WorldRadio Online became a paid-for, online-only publication. The once-free PDFs were taken down and any new content would have to be paid for. I'm unaware of any widespread fanbase of the now online-only paid publication which can only mean it's a matter of time before the publisher pulls the plug on the project altogether.

Also succumbing to similar commercial/financial pressures is the European publication HamMag.

Continue reading...

tags: WRO WorldRadio HamMag Ham Radio

( Comments : 0 | Full article )

 
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