AmateurRadio.com

Goodbye Chrome. It was fun while it lasted. But in the last day or so Google Chrome has become so crash-prone that it is unusable. Suggested solutions amounted to disabling plugins and add-ons but my installation was pretty basic apart from AdBlock. Nevertheless I took the step of uninstalling Chrome completely and then reinstalling again. But it still crashes. Just trying to sign in to Yahoo is enough to crash it.

So it’s back to Firefox. I don’t have time for flaky browsers.

This morning Dave Akerman launched another of his HAB flights from Brightwalton, a few km to the south of me. For the first time since I have been tracking the balloon flights on 434MHz, Dave’s payload was taking pictures and sending them back to ground. Several transmissions from two balloons were available, and as the balloons rose to about 10km, I just tracked their position and altitude.

Then I wondered how I would get on decoding the data and pictures. I tuned the rig to the appropriate frequency and heard an interesting sounding signal. It turned out to be 600baud RTTY. I pressed Auto Configure on DL FLDIGI and was encouraged  immediately to see that data started to be decoded.

Rather pleasingly, on the SSDV Habhub site I noticed my call listed against the pictures that my data packets, which DL FLDIGI uploads to the server, had contributed to. SSDV seemed a very robust protocol and quite often, I would get a solid data packet from the image, where perhaps a position report had failed.

I had not tried SSDV before, but it turns out that if you press S whilst in DL FLDIGI, you can see the image that you are downloading, Here you can see one of the better images that I decoded, when the balloon was around 30km high.

If you’re coming from sotawatch.org, welcome!

—Details—
Peak: W5N/BA-005 – 7284 [Socorro Peak]
Location: Socorro, NM, DM64mb
Time: 20 July 2013, 1700 UTC
Bands: anything I can manage. Likely 20m and up, and 2m
Mode: SSB preferred, but I want to try to muddle through some CW. I’ve never done CW without a computer (shame on me) so PSE QRS!

On 20 July, I plan to activate a nearby mountain for SOTA. This isn’t any regular mountain – the some parts of the road up to the peak is owned by EMRTC, or, simply speaking, its a bombing range. Therefore access is permit-only and this plan is tentative at the moment [edit — It’s a go!!]. However, at last night’s Socorro ham club meeting, I met a guy willing to be my escort, so I don’t get blown up, and to make sure I don’t steal anything, I suppose.

Map of the area and the Summit. [http://sotamaps.wsstvc.org/]

BA-005 is known as 7284 on the SOTA map, but the peak is commonly referred to as M-Mountain or Socorro Peak. A nearby peak which has a large, limestone M on it isn’t included in the database because it’s too near the taller peak.They only differ in elevation by about 60 feet.

This shorter peak is the home of the famous Elfego Baca Golf Shoot, where participants tee off at about 1500ft above and 2 miles awaythe hole. I think it’s a par 36 😀

Instead of golf, we’re going to shoot for some QSOs.

I’ll be using my new fangled End Fed Half Wave coupler and some conveniently placed towers. If those don’t work, then I’ll revert to some hamsticks. Stay tuned for more on the antenna project, and the summaryof the activation!

Ham Radio Two-Day License Class

Monument, Colorado
Sat Oct 19 and Sat Oct 26 (8 AM to 5 PM) 2013

Location: Tri-Lakes Monument Fire Station 1

 The Technician license is your gateway to the world-wide excitement of Amateur Radio …

• Earn your ham radio Technician class radio privileges
• Pass your FCC amateur radio license exam right in class on the second day
• Multiple-choice exam, No Morse Code Required
• Live equipment demonstrations
• Learn to operate on the ham bands, 10 Meters and higher
• Learn to use the many VHF/UHF FM repeaters in Colorado
• Find out how to participate in emergency communications

There is a $25 registration fee for the class.

In addition, students must have the required study guide:

HamRadioSchool.com Technician License Course $19.95

Advance registration is required (no later than one week before the first session, earlier is better!)

To register for the class, contact: Bob Witte KØNR

Email: [email protected]  or Phone: 719 659-3727

Sponsored by the Tri-Lakes Monument Fire Radio Association

 For more information on amateur (ham) radio visit www.arrl.org
 or www.wedothat-radio.org   

Fresh from the Unless You’ve Been Living In a Cave, You’ve Heard of This department, there’s been much ado over the FCC Petition for Rulemaking seeking encryption for emergency communications.  I won’t go into the details of the petition as you can read that several places elsewhere.  Technically encryption on amateur radio bands is illegal.  However, in reality the FCC has been letting it happen for years and the ARRL has turned a blind eye to it.  D-STAR uses a proprietary vocoder that takes an analog voice signal and converts it into a data bitstream.  The algorithm isn’t publicly documented and you can’t decrypt it, unless you buy a proprietary chip.

Some may quote § 97.309 (4)(b) which basically says one can transmit an “unspecified digital code” as long as the digital code is not intended to obscure the meaning of the communication.  Presumably the people who created and use D-STAR don’t intend to obscure the meaning of the communication, so perhaps it is within the law.

So, say I create a new digital communication mode.  It features a compression algorithm and I just happen to XOR the data stream with a 10 million bit pseudorandom bitstream to randomize it so a long stream of zeros or ones won’t screw up a modulator.  I document the algorithm and the 10 million bit key on some corner of the Internet.  It’s technically publicly documented, but in practice no one will go to the trouble of attempting to build a decoder.  I’ve achieved encryption in a roundabout way.  Whether my intentions were to obscure the meaning of the communications or make a modulator-friendly bitstream is anyone’s guess.  But with the inaction over the D-STAR vocoder and the wording of § 97.309 (4)(b), intention rules the day.  So while this debate over the petition is being framed in a discussion of encryption, it’s really the intent to obscure communications that’s at the heart of this.

I don’t have a horse in this emcomm race, but I’m not in favor of allowing obscuring messaging.  If the FCC does allow it, others are going to want to use it for their noble causes, like preppers under the guise of “homeland security”.

(D-STAR is a registered trademark of Icom, Inc.)