Friday, December 14, 2012

RF Overkill?


I ran across this item this morning.  (Read the post.) Somehow, it rang a bell for me about ham radio - QRO, "radiosport", etc.  It's interesting what the average deer hunter pays out each year. It puts radio into some perspective.

Wednesday, December 12, 2012

Chromebook printer gotcha

The Samsung Chromebook (previous post) is a fine little machine. Simple setup, simple operation. What could go wrong? Well, try to integrate it with your home network! You can't directly connect to anything, like your printers on the network. (There are SSH and FTP apps, but they seem to work through a proxy outside the local net.) Google wants you to use its Cloud Print service (beta!), which allows you to print to a file in the cloud which is then queued for any cloud-connected print server for which you have permission.

It's on you to create a cloud print server for your local printers if you want to print from the 'book. To do this, you must 1) log in to your PC (under your ID of course), 2) run the Chrome browser, 3) set up a server process, and 4) configure sharing with any Google IDs you want to have printing. Your local PC becomes a server (and it has to be turned on), and you have to be logged in.

It's a little more complicated than that for us, since we have a number of local PC user accounts between several family members. The print server has to be configured separately for each user who might be using the PC, and each user has to share the access properly. There is no simple way to run the server as a daemon or service. (It can be done, however. See this article for a Linux method.)

What they really suggest you do is to buy a new Cloud Print friendly printer, with the server capability built it.  HP calls this "ePrint". There are quite a few models available in a low to moderate price range.  For example, the HP 6600 all-in-one. Turns out we've got the HP 6500, with no Cloud Print...

That adds $100 or so to the price of the Chromebook.  Caveat emptor.

Tuesday, December 11, 2012

Samsung Chromebook for the XYL

We have been struggling with some equipment failures while trying to provide a good platform for Eva to do her e-mail and other moderate computing stuff.  (Alas, our beautiful old VAIO laptop has given up the ghost.)

Enter the Samsung Chromebook.  It's really well priced, and for someone who really does NOT want the complexity of a traditional OS, and who will always have WiFi, it's just the ticket.   We think!

One more foot in the Google world, for better or worse...

Wednesday, November 21, 2012

DC power grid still runs in San Francisco

DC Elevator Motor
Fascinating bit of techno-history persisting in the modern day.

http://spectrum.ieee.org/energy/the-smarter-grid/san-franciscos-secret-dc-grid .
In the early days (ca 1920) some hams could run their radios with the "B+" (plate voltage) coming straight from the DC power mains, saving money on expensive power supplies.  But if you needed high voltage for your transmitter's final, you might have needed a motor-generator (dynamotor). That would have been a big expense compared with an AC transformer/rectifier.

Sunday, October 28, 2012

Least Helpful Message Yet

"...government officials are urging people to plan for the worst." (CNN Report, concerning NYC & Hurricane Sandy.)

As in the end of the world?  I'm more optimistic than that.

Saturday, October 27, 2012

Antenna repair


Andrew from XX Towers inspected and adjusted the AA6E antenna farm today.  The SteppIR and mast are now pinned to the rotator.  No more windmilling unless something breaks!  We have a new Hallas-style 80 / 30 M sleeve coupled dipole, too.

So we are now officially restored after Tropical Storm Irene last year. Just.in.time.for.Sandy.  Grit teeth.

If this is the new climate regime in Connecticut -- one Tropical Storm / Hurricane per year -- I don't care for it.

Monday, October 22, 2012

Sic Transit Gloria Mundi

I see that the Hilberling PT-8000A has replaced my Elecraft KX-3 on the top line of the Sherwood receiver test results.

The Hilberling commands about 17x the price of the Elecraft.  On the other hand, it is provided in your choice of five designer colors.

(tks I0GEJ.)

Sunday, September 30, 2012

High Tech Infrastructure

Weil-McLain Boiler / DHW system
We've replaced our 30 year old oil boiler and hot water system with new 95% efficient natural gas equipment.

Bringing in the gas line from the street was a job, since we had to trench through granite ledge. Fortunately, the gas company was willing to do it on their nickle.

Our friends at Viglione Heating & Cooling produced a nice bit of industrial art in our basement.

Now we just have to count on a rising oil to gas price ratio and the passage of time (8 years?) to start making a profit. Meanwhile, we can feel green (less CO2) and happy not to import oil -- but sad about dirty fracking. Nothing is simple.

And there's an on-board microcomputer to be hacked!

Friday, September 07, 2012

Reinventing Ham Radio? - Pogue

"You might think that we’ve exhausted every variation on electronic communication — text, audio, video — but you’d be wrong. A new one is quietly winning over millions of gadget fans. They’re free apps with names like Voxer, HeyTell and Zello, and they really do mess with the rules of the game."  -- David Pogue, New York Times
It's Ham Radio (e.g., D-Star) without the license.  Seriously,  Amateur Radio may need to lose some of its exclusive focus on FCC-licensed communications, to bring in a little new energy.

Sunday, August 12, 2012

A New Leaf: QRP and the KX-3

The latest project is to put the Elecraft KX-3 through its paces.  The kit arrived Thursday afternoon.  Assembly was complete on Friday, and now we're on the air.  The preferred mode is 5 Watts CW, leaving a little headroom in case of "difficult conditions" (up to 12 Watts available).

The receiver is doing very well.  (See the latest Sherwood results.)  The transmitter is fine so far, but it gets some help from the 3-element SteppIR antenna upstairs.

First Q's: DK2SC (20 M), CT1EDJ (15 M)

It's very impressive how much functionality is compressed into this little box.  I calculate its volume is about 1/20th of the Ten-Tec Orion on the main desk. The Orion does deliver 8X the power, and it has a few other nice features, but I'm thinking how I could better use that desk space.

Monday, July 16, 2012

Interesting Little Boards

Shortly, I'll have three little computer boards to understand, play with, and possibly (just possibly) build into some useful projects.

The Arduino Uno is "slow" (16 MHz) ATmega328, has limited RAM and OS support, but is very flexible for interfacing and control applications. Easy C-style programming for simple applications. $27 at Digikey.
The Raspberry Pi is fast (700 MHz ARM) with 256 MB RAM, Fedora Linux, etc., and it's amazingly cheap ($35 US at Allied Electronics, if you can get one!).

As a full-blown Linux system, the Raspberry (and BeagleBoard, below) will require somewhat more software sophistication to get in the game.
The BeagleBoard XM is fastest (800-1000 MHZ ARM) with 512 MB RAM and full set of peripheral connections, running Ubuntu Linux, Android, and others. $149 at DigiKey.

This board has the makings of a DIY netbook computer or tablet, even including a camera interface.

You get extra points if you can program the built-in TMS320 DSP processor.  Usually for audio and video codecs, the DSP development environment is complicated. (To be charitable)

I've mostly been working the the BeagleBoard XM, and I use a lot of its I/O capabilities.  (This is the only board of the three that seems to directly support audio input.)  It provides all the fun and frustration of working in a full Linux environment (including video display, mouse and keyboard if you want), but there are few extra headaches dealing with the embedded aspect.  (E.g., configuring GPIO pins and boot files.)

The rule seems to be: use the simplest board that will support your project without elaborate daughter cards, etc.  In a one-off project it's really easy to use many hours and dollars to shoehorn a project onto a board that doesn't quite fit.  On the other hand, if all you need is blinking lights of one sort or another (even a complex Morse keyer) the Arduino's easy programming system can really save time.

These are all open source boards, making it possible to do your whole project in an open style (software and hardware), a big plus for Amateur Radio DIY work.  There is a huge amount of online information and help forums for all these boards.

Friday, July 06, 2012

Software Defined Radio for Every Purpose

"Right now, most people probably couldn't imagine why they'd want software-defined radio hardware in their homes. But people said the same thing about microcomputers in the 1970s."
 Interesting overview of SDR vs the communications world at Ars Technica, featuring USRP and Phi.

Sunday, June 24, 2012

Amateur Radio and Innovation in an Age of Austerity

Eben Moglen
Why would I watch an 88 minute YouTube speech by Eben Moglen?  It was John Naughton's hearty recommendation for  his talk given at F2C:Freedom to Connect 2012, Washington DC on May 22.

In a nutshell, Moglen gives an eloquent and provocative story about how what will save us all, economically, is innovation, and innovation in these economic times (austerity all around) will only succeed if we promote free (as in free speech) software and place tools for experimentation in the hands of young people around the world. (Jabbed for their closed nature: Apple, Facebook, etc.)  We need control of our own servers. (and logs!) Powerful stuff that folks in the Linux / GNU camp can all believe in.

So should everybody go spend an hour and a half on this?  Maybe not, but there were several comments at the end of the Q&A session that were related to Amateur Radio.   An unexpected reward for persevering!

Some folks brought up the Maker Movement as an example of a community that is developing along the lines Moglen is describing.   Then (at about 1:17:00), Doc Searls confessed that he had started out in life as a radio amateur, and he called on an audience member, Dwayne Hendricks (WA8DZP), to give a short spiel on Amateur Radio - no, it's not dead, and in fact it provides a great platform for open technology development.

Dwayne relates some of his work, suggesting among other things that hams can develop platforms for non-hams to use.  (This raises some questions for me!)  He also takes an unfortunate dig at the ARRL in these comments to this professional internet/computing audience.  (In another setting, his point about ARRL's stance vis-a-vis innovation deserves discussion.)

For your convenience, here is the full video:


Thursday, May 24, 2012

QST & digital QST


The new digital QST edition is now on the web, accessible to ARRL members.  It's a good effort -- at least if you like the new web magazine reading experience.   It is being provided to members as a no-extra-cost addition to the traditional print version.

I hope the pdf version won't go away completely.  That's the format that appears on the annual publications CDROM and on the QST web archives up through 2011. The new format is fine (well, if you like it!) for on-line reading and limited off-line reading, too, but it is a proprietary and DRM-restricted format that probably won't be convenient (if readable at all) 50 years from now.

I was interested in the new QST logos that are cropping up.  There are several variations. One is at the top of this post (I understand it is for the iOS app), and here is another:


But I like to look through the QST archives to how QST presented itself in the very earliest days.  The first "logo", from 1915, was this neoclassical marvel:


Then, in the late teens and into the twenties, you might have seen this one.  (Color added.)


This is the classical logo for me.  Its block lettering and at least some of the lightning bolts continue into the modern era.  The slogan now says "Amateur Radio" instead of "the Wireless Amateur".  I like this old graphic, but I'm pleased that there is so much continuity in today's version.

Finally, take a look at the first digital QST cover (June, 2012):


Bold and hyperactive design, and presented twice for good measure!

Monday, April 09, 2012

Adventures in Platform Independence

So I have this nice program developed that will allow us to transmit compressed communications audio over an Internet link.  It will be part of a remote Internet receiver that will support W1HQ, the club station at ARRL, Newington, CT.

The program came together fairly easily, using old-fashioned Linux / C programming, together with the Speex and Portaudio libraries.  The sending program runs on an ARM-based Beagleboard card, and the receiving side should run on any Linux box running Ubuntu or your favorite Linux distro.

Along with the audio software, there is an independent rig control function using Python, wxWidgets, and Hamlib.  That should run nicely on Linux, Windows, or what-have-you.

Since our W1HQ crew really needs to keep their Windows station computer, we do need to make the audio receive software run under Windows, along with rig control.  That's where today's lesson begins.

Porting to Windows!

The problem of porting Linux C code to Windows is the subject of a lot of Internet discussion.  It needs to be done frequently, but the process is not simple.  For one thing, the programming tools are rather different.  While the basic principles are the same, all the details are different.  In Windows you generally code within a complex IDE system (Interactive Development Environment).  Managing libraries, dealing with the graphic user interface, and even finding useful "help" files are all a challenge. But the killer, for me, is the unavoidable fact that the underlying operating system just does things differently from Linux.  This shows up in many ways, but my problem specifically was dealing with Internet communications (sockets).

I looked at 3 approaches, before finding a solution that might work for us:
  1. Visual C++ and Visual Studio.  This is Microsoft's preferred development system, using the big IDE model.  Fortunately, there is a free "express" version that might work for us.  I could get the Portaudio and Speex libraries to compile, but the socket programming model seems to require serious recoding work.  It would be possible, but it's almost like starting from scratch.  Furthermore, we'd end up with  Windows source code and Linux source code that would have to be maintained in parallel.
  2. CygwinCygwin is software that runs under Windows and provides a Linux command line interface.  Compiling with gcc works in Linux style, so that's good.  However, there is no support for Linux sockets model, so it's no help in the end.
  3. MinGWMinGW does not provide a full Linux run environment, but it has a number of features that help you compile Linux code to run under Windows.  Compiling the libraries is no problem, but still there is no sockets compatibility.
Not Porting to Windows!

The only solution I've found that won't require investing time in Windows C programming, is to virtualize the problem.  That is, set up a virtual Linux PC inside our Windows box using the free Oracle VirtualBox.  A good modern PC should have enough horsepower for this.  (We'll see about the W1HQ machine!)  Once this is set up, you can run all the code the way it was meant to be run.  The price to be paid is 4-8 GB of disk space and 300-500 MB of RAM.  Since our needs on the Linux side are very modest, we may be able to pare down the memory requirements substantially.

VirtualBox runs the audio software fine under Windows 7 on my home machine.

Update 9/8/2012:  VirtualBox works nicely, but it has a large footprint on any average size computer, so it's probably too much to run at W1HQ without an upgrade.  RAM upgrades are cheap, but it's probably worth another look at Windows coding.  I've simplified the audio transport to use UDP, so there's probably less OS dependency.  We'll see.

Friday, February 17, 2012

ABCs of SDR

The new book is out.  It's a concise low-math (almost zero math) description of what SDR (software defined radio) is all about, for the general ham radio audience.

The short message:  It's the main technology at the core of about every HF radio you can buy these days.  If a radio has "IF DSP" it normally has an SDR back end.  Front ends vary, from minimal ("pure" SDR) to conventional, but the digitization and digital signal processing is mostly the same.

Order from ARRL or your favorite bookseller.

Wednesday, January 18, 2012

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