ARRL Field Day 2009

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2009-fd-logo-298x200The ARRL Field Day is one of the more popular and fun ham radio events during the year. You or your club can make Field Day whatever you want: a real contest, some time out in the woods, a public service event, drinking beer with your buddies …. whatever.

Field Day this year is June 27-28.

The ARRL promotional materials for Field Day are now available on their web site.

Here is the Public Service Announcement video:

By the way, the ARRL logo for Field Day looks good. Nice work by the ARRL graphics department!

73, Bob K0NR

Added on April 12th: Noticed a good Field Day post by K3NG

Paying My Dues

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hamIn the past few years, I have noticed that it is easy for me to miss paying my membership dues for the various amateur radio clubs I’ve joined. Despite the trend towards electronic mail, there is a huge pile of paper mail that ends up on our kitchen table. Somewhere in there is a little postcard or letter reminding me to pay my dues. It often gets swept into the junk mail pile and into the trash can. Worse yet, many clubs just put out the blanket message that “all dues are due” in the club newsletter or an email message.

I did a little inventory last night of my membership status with the various clubs and sure enough, I am delinquent with several of them. Some of these organizations are repeater groups that only meet once per year, so there is no natural reminder built in. It is interesting that none of the clubs have followed up with me and asked “did you really intend to drop your membership?”  Many clubs are seeing a flat to declining roster due to the demographics of the ham community, so you’d think they would focus on retention.

Based on my experience, I reached these conclusions:

  • With some clubs struggling, I will pay more attention to this renewal issue so that I am supporting the local ham community.
  • Even though I operate my own UHF repeater and tend to hang out there, I’ve decided to increase my support to several of the local repeater groups. I’ve focused on the ones that actively support ARES and RACES activities, an important part of the amateur radio service.
  • Radio clubs can really benefit from monitoring their rosters and being a little more assertive on retaining members. I bet they could bump their rolls by 10 to 20% with just a little follow up.

What do you think?

73, Bob K0NR

This Spewed Out Of The Internet #2

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0511-0701-3118-0930Been spending time on airplanes again. I think my business card should show my office as Seat 8C (always go for the aisle seat).

Here’s a few things flying at me on the web. K3NG reports that the new FCC Chairman has a reputation for being data driven, you know, like using facts and everything. I can go for that. Here’s the ARRL story on the FCC Chairman (Julius Genachowski).

In case you missed it (I did), Woz has been on Dancing with the Stars.  Woz is a cool guy, but who cares?

Fark.com had an interesting photoshop sequence that started with a guy adjusting some sort of antenna. Lots of creativity by the photoshopping readers. The poor guy is probably trying to figure out how to receive digital television.

From the Things That Really Matter Department, a big friggin’ asteroid just missed hitting the earth. OK, it missed us by 49,000 miles but in cosmic terms that is half a freckle.

I just noticed this article on the ARRL web site about Laura Smith, the FCC Special Counsel for amateur radio enforcement. She says will probably get her amateur radio license someday but thinks she needs to learn Morse Code first (read the story to understand why).

Closer to home, I have been tuning up my packet radio gear which has been sitting on APRS for the past year or so. It seems the local RACES folks want to use Winlink for emergency comms but I am not sure my TNC is up to the task.

—   73, Bob K0NR

Tweaking the Blog a Bit

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wordpress logoThis evening, I am messing around with the blog a bit. I recently updated WordPress to version 2.7, which is a significant upgrade. I am still figuring out what’s new.

I decided the old template had just too much blue, so I switched over to “Journalist”…nice and clean. Also, the main text column is set up wider, which fits most computer monitors better. Maybe too boring, we’ll see. It is soooooo easy to change themes in WordPress.

For several months now, I’ve been using WP-SpamFree which does an awesome job of keeping the comments spamfree.

I finally got around to adding a blogroll. It seemed like just another thing to keep up to date, so I resisted doing it. However, I noticed that my web page was getting lots of hits off some of the other blogs that had me on their blogroll, so time to return the favor.

73, Bob K0NR

International Standards

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radio_47I just got back from Mobile World Congress, the biggest mobile wireless show in the world.

The hot topic is an emerging mobile phone technology called Long Term Evolution (LTE). The basic idea is that there will be only one 4th Generation (4G) mobile phone standard worldwide. What a concept…one mobile phone standard that you can use anywhere on earth. (Well, there is that small detail of different frequency bands being available in different regions. And there are really two variations of LTE hiding in the standard. But we can still tell each other this is a single standard.) Of course, there is that competing 4G standard called WiMAX.

Worldwide technical standards are a good thing.

The show was in Spain and I stopped in the U.K. on the way home. This reminded me of another worldwide standard that doesn’t exist: driving on the right side of the road. In this case, a country only has two choices: drive on the right side or drive on the left side. Most of Europe drives on the right side but the U.K. drives on the left. You would think that the world could have agreed on this but apparently not. Go figure. According to wikipedia, 66% of the world population live in right-hand drive countries, which means that is the right approach (weak pun sort of intended).

Another world non-standard is electrical power. Around the world there are various combinations of line voltage, ranging from 100 Volts to 240 volts RMS with a frequency of either 50 Hz or 60 Hz.  I am not sure how all of these different choices evolved but by now they are very entrenched. My engineering mind wishes that we were all on the same power line standard, so that we can all be more efficient: one power plug could be used all around the world.  The adoption of switching power regulators has helped this situation, since one power supply can handle all of the power line definitions around the world. Add in a small collection of plug adapters and the problem is solved.

One defacto standard that is common around the world is the QWERTY keyboard, which originated with the typewriter. Later it transferred over to computer keyboards and now it shows up on many of the so-called Smartphones (see BlackBerry). This is another example of a very entrenched standard….there is probably a more optimum keyboard layout but this is the one that everyone has been trained on. The Apple iPhone delivers an innovative touchscreen interface (that everyone else is trying to copy and one up) that is redefining the accepted smartphone user interface. Even the iPhone chose to implement the QWERTY keyboard in touch form as the way to enter text.

The one non-standard that has caused the most pain and suffering around the world is the lack of a common connector on wall-wart chargers. I blogged about this a while ago. It seems that every manufacturer does it differently and they are not even consistent within their own product lines. In response to some pressure from the European Union (and my blog, I am sure), a coalition of mobile phone manufacturers have announced they will implement a common charger format:

The GSMA and 17 leading mobile operators and manufacturers today announced that they are committed to implementing a cross-industry standard for a universal charger for new mobile phones. The aim of the initiative, led by the GSMA, is to ensure that the mobile industry adopts a common format for mobile phone charger connections and energy-efficient chargers resulting in an estimated 50 per cent reduction in standby energy consumption, the potential elimination of up to 51,000 tonnes of duplicate chargers1 and the enhancement of the customer experience by simplifying the charging of mobile phones.

The group has set an ambitious target that by 2012 a universal charging solution (UCS) will be widely available in the market worldwide and will use Micro-USB as the common universal charging interface. The group agreed that by the 1st January 2012, the majority of all new mobile phone models available will support a universal charging connector and the majority of chargers shipped will meet the high efficiency targets set out by the OMTP (Open Mobile Terminal Platform), the industry body who developed the technical requirements behind UCS.

The Micro-USB seems like an obvious choice. I wonder why it takes until 2012 to get this done? If they do get this accomplished, manufacturers of other electronic devices will follow. Heck, we might even see it on a 2 Meter handheld.

73, Bob K0NR

Update (19 Dec 2009): I came across this article from Mental Floss on the history of driving on the right/left side of the road.

This Spewed Out Of The Internet #1

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I’ve been on airplanes again, so trying to catch up. Here’s some things that have spewed out of the internet onto my computer.

Netbooks are the hot item in the computer world (see my previous posting). There is a recession on, you know, so people want to spend less money. It turns out that Psion has trademarked™ the word NetBook™, even though they don’t actually produce a netbook™.

It turns out that the US Congress, in its infinite wisdom, has decided to delay the DTV Transition….sort of. President Obama signed into law the DTV Delay Act. This law moves the mandatory changover from analog TV to Digital TV (DTV) from Feb 17th to June 12th. Except this is optional, so one third of the television broadcast stations are expected to change on Feb 17th. So if you and Grandma are confused, you are not alone. The FCC published a list of stations that are planning to change over on Feb 17th. See my previous post for more drivel.

PC Mag published their list of The Best Free Software. This is worth checking out.

Russia decided to exit the space tourist business. I have to admit that I have enjoyed having a few space tourists with amateur radio licenses operating from the ISS. On the other hand, when did the International Space Station become a tourist destination?

Laura L. Smith was named as the Riley replacement. It is good to see the position filled. There is some concern because she is not a licensed radio amateur. OK, let’s give her a chance and see what she can do. Of course, I did have to comment on the surplus of lawyers in the FCC.

Here in Colorado, the legislature is working on a bill to deal with Driving While Cellphoning. Concerned that this could impact amateur radio mobile operating, our ARRL Section Manager Jeff Ryan, K0RM, and Public Information Coordinator Robert Wareham, N0ESQ, took action to get the bill modified to accommodate amateur radio operation. Thanks, Jeff and Robert, for taking this on.

73, Bob K0NR

The FCC Gets Technical

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While we wait for the official announcement that Julius Genachowski will be the head of the FCC, I have been pondering how the FCC management seems to be mostly lawyers by training. Last night I had this strange dream:

In a surprise move, President Obama announced that Fred Technofarble will head the Federal Communications Commission. Technofarble is uniquely qualified for this role due to his strong educational background in both engineering and law. His undergraduate degree in electrical engineering is from MIT and his law degree is from Harvard. His main area of study has been the use of government policy and regulation to encourage technological innovation. Most recently, he has been employed as the Chief Technology Officer for a Fortune 500 electronics company.

Technofarble is well-known as a computer and ham radio geek, spending his precious free time tinkering with electronic projects in his basement. He told the press that his first action will be to institute a mandatory testing policy for all FCC employees in professional positions.

“We’ll give them a very basic test that covers electromagnetics, communications and electronics. You can’t be making up regulations for something that you don’t understand, so we’ll insist on a basic level of technical knowledge for all FCC staff. This will be an easy test…the typical engineer or technician will be able to pass without studying but I expect about half of the lawyers to fail. Anyone that fails will be given 3 months to study and successfully retake the test, otherwise they will be terminated.”

Technofarble also indicated that anyone holding a valid Amateur Radio License would be given full credit for the required test.

Then I woke up.

73, Bob K0NR

Agilent FieldFox RF Analyzer

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Photo © Agilent Technologies 2009 All Rights Reserved

I am a bit of a test equipment junkie….it has something to do with working in the electronic measurement business for most of my career. There are many great pieces of test equipment out there but every once in a while, one comes along that really captures the imagination. Over the weekend, I got my hands on the new FieldFox RF Analyzer from Agilent Technologies. This analyzer is a combination 2-port network analyzer, cable tester and spectrum analyzer in one compact package. Add in an external sensor and it measures RF power, too. [Disclosure: I am employed by Agilent.]

With a base price of $7600, this instrument is probably out of the price range of most radio amateurs. However, the RF engineers and technicians out there in the electronics industry will appreciate its measurement capability and value.

The first thing I did was connect it up to my vertical antenna used for 2 Meters and 70 centimeters. I was able to check a few things on the antenna system and monitor some signals. Funny thing, when I tuned to the 2 Meter ham band, I didn’t see any transmitters on the air <sigh>.  So I switched over to the FM broadcast band and did a scan of 86 to 110 MHz. The spectral lines you see sticking up are the FM broadcast transmitters in my area.

Then I checked the VSWR of the antenna system (as seen looking through the end of the cable).  The sweep below shows the VSWR of the antenna system versus frequency. The center of screen is 146 MHz and the marker is set at 146.52 MHz. The VSWR doesn’t quite stay under 2.0 over the entire band.

Then I switched to the Cable Tester mode and displayed Distance to Fault (DTF). The DTF display shows the return loss of the cable as a function of the distance along the cable. (The FieldFox analyzer can correct for the propagation velocity but I did not have this feature turned on. So the distance shown is in error by that amount.)

The bump in the middle of the display is about 60 feet down the line, which corresponds to where an inline surge supressor is installed. Apparently, there is a small “impedance bump” in the line at that point. At the right hand side of the display, around 110 feet is an impedance change due to the antenna. If I had a good 50 ohm load on the end of the cable, we would not see this blip. The DTF measurement is a broadband measurement so anything that is not a good 50 ohms across all frequencyes (such as a high Q antenna) shows up as an impedance blip.

These results are not bad but I expected the impedance of the antenna system to be better than this. If I can hang onto the analyzer for a few more days, I’ll be sure to investigate the antenna system more carefully. Nothing like having the right test equipment to make useful and accurate measurements.

73, Bob K0NR

January VHF Contest – 2 Meters at 9500 Feet

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Activity was light during the ARRL January VHF Sweepstakes, but I had fun anyway, working more grids on 2 Meters than I expected. The January VHF contest is not a big deal for me but I try to at least get on the air. In previous years, I have operated backpack portable for the contest.

This year, I was up at our cabin near Trout Creek Pass in the western part of DM78. The cabin sits at about 9500 feet in elevation with a good radio horizon in most directions. It is blocked a bit to the west due to some 14,000 foot mountains. I don’t have serious antennas up there (yet), so I decided I would just temporarily install a 2 Meter yagi and focus on working that band. (I am thinking I need to get serious about 2M VUCC.) The snow can be quite deep so I wasn’t sure that I could get the SUV up the driveway. Since we might have had to carry everything up on snowshoes, I was thinking minimal equipment. (It turns out the neighbor with a frontloader cleared the driveway, so this was not a problem.)

The rig is a Yaesu FT-847 (one of my all-time favorite rigs) that puts out 50 Watts on 144 MHz. I probably should have brought my Mirage amplifier along but, again, I was going for minimal equipment. With only one band to worry about my operating focus was, well, only on one band. This basically meant hanging out on the calling frequency (144.200 MHz) listening for activity and making calls. During other contests, I’d be jumping around from band to band, trying to make sure I didn’t miss anyone. The one band approach certainly is simpler…perhaps a bit boring.

I was careful to set up my station for both SSB and CW modes. In previous contests, I’d forget about CW until I really needed it….then scramble around for my keyer, frantically trying to plug the right cable into the right jack and get it all working.  For CW, I had my XT-4 CW Memory Keyer, which is a simple, but effective 4-memory keyer. I loaded up the first memory with a “CQ CQ CQ de K0NR” message. The second memory was loaded with “R R R DM78 DM78″….which sends my vhf grid to the other station. The third memory is used for calling a specific station. I manually send the other stations call sign, then punch the third memory “de K0NR K0NR DM78 DM78”. The fourth memory is to acknowledge that the contact is complete: “QSL QSL 73 de K0NR K0NR”.

I put the 2M9 Yagi from M2 on a TV mast strapped to the front deck of the cabin. There was very little wind so I didn’t bother to guy the mast, but I did take it down at night in case the wind came up.

Most of the stations I worked were in my grid and DM79 (greater Denver).  I made only 20 Qs but picked up 9 grids (DM68, DM69, DM78, DM79, DN70, DN80, DM89, DM98 and EM09). This is a rather high grid/Q ratio and I felt like I did pretty well in terms of picking up the available grids.

I worked N0KE over in the western part of the state in DM69. On this path, some of the adjacent mountains get in the way. I heard Phil calling on CW on 144.200 MHz and worked him on that mode. I doubt that we would have completed the contact on SSB. CW really does get through when you are operating near the noise floor. I also managed to snag N0LL over in EM09 Kansas using CW. I have worked Larry in the past on 2M from other locations but not from this far west. I figure that he is about 390 miles away from the cabin….not bad for 50 Watts on 2 Meters. Of course, Larry has an awesome station on VHF and puts out a big signal. My wife Joyce K0JJW did an impromptu rover run over to DM68 (about 6 miles away) to activate that grid. Another nice surprise was finding KI0SK out roving in DN80 and DM89. Those are relatively rare/unpopulated grids so the only way they get activated is via a rover station.

So my summary is a poor showing on number of QSOs but pretty decent on number of vhf grids. And a weekend in the mountains messing around with ham radio is always a good time.

73, Bob K0NR

ARRL January VHF Sweepstakes This Weekend

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Just a reminder that the January VHF contest is this weekend, starting at noon on Saturday Mountain time. I will be at our cabin up in the mountains (DM78av) with no real antennas up yet but I’ll have a decent Yagi set up temporarily for working 2 Meters. I’ll listen on the calling frequency 144.200 MHz for SSB contacts (if it gets busy, I’ll move up to 144.220 MHz). I’ll also have a radio listening on 147.42 MHz for anyone working FM. (Use of 146.52 MHz is prohibited for contest contacts. Dumb rule, long story.)

This is a great opportunity to try out weak-signal VHF since there will be stations on working the contest. See the contest rules on the ARRL web site.  If you are new to VHF contests, see my page: How to Work A VHF Contest.

73, Bob K0NR

Been Reading Stuff Again

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There have been quite a few news items, blog posts and tweets flying across the net lately. Here’s what I have been reading:

It looks like the FCC Chairman Kevin Martin is out and Julius Genachowski is in. I’ve only found “Julius is a good guy” articles without much detail behind them, so I guess we wait and see.

A company called CellAntenna wants to be able to sell cellphone jammers. I am totally in favor of it as long as I am the only one that gets one. I’d keep it in the car and jam all of the people driving while cellphoning (except for me, of course).

Check out this new cellphone from “Sumsing”, pretty funny video.

Interesting post from Kelly AB9RF about Why the Hell Would You Want a Ham Radio?

Jeff KE9V wants his QST electronically. I think he has a point.

Bruce Vaughan, NR5Q, from Springdale, Arkansas survived WWII with a few stories to tell. He loves to build radios and got an email from a musician that said he was in a band called The Eagles. Bruce invites him over to the house….turns out it is Joe Walsh.

Obama thinks we need to delay the shutoff of analog TV. He is wrong….time to go through the transition and deal with it. Rip the band-aid off quickly. (Did you notice that watching television is now a right guaranteed by the US Constitution?)

CQ Magazine embraces eQSL for their awards program. Jeff KE9V questions whether we are headed done the wrong path with electronic QSLs.

K3NG gives us a list of things to test Whether We Are Part of the Problem.  Close call for me, as I do think saying 73s is dumb….but I don’t correct people on the air.

Good reading and 73,  Bob K0NR

How Many Gigafarbles is That?

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As the storage capacity and cost of computer hard drives continue to improve, it just amazes me how many bytes you can store for a reasonable cost. For example, you can purchase an external 1 terabyte drive for less than $150….which is probably a good thing, since downloading a few videos and your daily email will fill that up in no time.

This got me thinking about how megabyte and gigabyte have made it into everyday language. Even Grandma knows that you want lots of gigabytes in your hard drive. Expect terabyte to make it into dinner conversation shortly. These prefixes that help us handle humongoid numbers come from the International System of Units (SI).

When I first started out messing around with electronics as a kid, I had to get used to these units. Back then it was mostly kilohertz and megahertz, along with kilohm and megohm. Not too bad. Capacitance was in microfarads and picofarads. (There was this strange usage of micro-microfarad, which I eventually figured out was the same as picofarad.) I didn’t know a tera from a giga.

There are twenty SI prefixes listed on the NIST web page, including:

1024 yotta Y
1021 zetta Z
1018 exa E
1015 peta P
1012 tera T
109 giga G
106 mega M
103 kilo k

When we get to 1000 terabytes, that will equal a petabyte. I don’t think I’ve ever used peta to refer to any numerical value, and certainly not exa, zetta and yotta. I kind of like the sound of yotta, as I can hear myself saying “there’s a yotta bytes on that 5 yottabyte hard drive.”

On the low end, we some other prefixes to deal with:

10-3 milli m
10-6 micro µ
10-9 nano n
10-12 pico p
10-15 femto f
10-18 atto a
10-21 zepto z
10-24 yocto y

I have often used the prefixes up to femto and might have said atto once or twice in my career, but never zepto or yocto. Isn’t zepto the name of one of the Marx brothers? 🙂 I’ve noticed that nano has worked its way into dinner conversation, via terminology such as nanotechnology. I’ve even heard a few non-technical people say something like “that will last about a nanosecond.”

It seems that things are getting more numerous (bytes on hard drives) and smaller (width of a transistor element) at the same time. This stretches out the dynamic range that we end up dealing with, and not just related to technical fields.

We just seem to have a lot of stuff.

73, Bob K0NR

Podcast: Linux in the Ham Shack

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Over the past few years, I have developed the habit of listening to podcasts on my iPod as an alternative to broadcast radio. (See my post from April 2006: Competing for Ears.) Of course, some of my favorite podcasts are on the topic of amateur radio. I’ve noticed that some of them have come and gone, and my interest in them varies over time.

Recently, I just came across a new podcast called Linux in the Ham Shack, by Richard KB5JBV and Russ K5TUX. Richard also does the Resonant Frequency podcast. Both of these podcasts are available via iTunes and probably a whole bunch of other feeds. For you Linux enthusiasts, Russ’s call sign is a vanity call chosen for its Linux significance.

Most of my PCs run some version of Windows, but lately I have gotten more interested in what Linux can do for me. Earlier this year, I took one of my old PCs running Win98 and gave it some new Linux brains (Ubuntu). I have to admit that I have just been running non-ham radio apps such as OpenOffice and Firefox on that machine. I’d like to turn on PSK31, APRS, WinLink and other digital modes so this new podcast sounds like a great resource.

The first few episodes of Linux in the Ham Shack were interesting and helpful, with a nice interplay between Russ and Richard. Keep up the good work, guys!

73, Bob K0NR

Managing Twitter Overload

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Twitter is The Next Big Thing on the web…sometimes referred to as microblogging.  (For some background on Twitter, see my earlier post: Twitter: Yet Another Web Thing.)  Several of the ham radio bloggers have tried Twitter and have gotten frustrated with it. Steve K9ZW says that

Basically the few unique bits of information passed are overwhelmed by endless droning Tweets about microcosms of banality trying to add value to the mundane.

I think NØHR captured the issue succinctly by describing Twitter as having a poor Signal-to-Noise Ratio.

I suppose this is what you get from a free, web-based communication service that asks you “What Are You Doing?” and gives you 140 characters to form the answer.

My view is that we are living in a world where the barriers to communication have been dramatically lowered, meaning that there is more information flying in our direction than ever before. Twitter is just the latest example of this. If you “follow” a hundred or so people all tweeting away with their What Are You Doing? stream of consciousness,  you are going to end up with a Pile-O-Stuff of questionable value. To make this useful, you must be careful about who and how many people you follow or apply some kind of filtering/sorting mechanism to keep it under control. I noticed that WA4D expressed a similar view.

This is really no different from when we subscribe to other forms of electronic distribution, such as email lists (e.g., Yahoo groups) and RSS feeds. The reality is that you can easily get overloaded by all of the content out there….more than any human has time or energy to read. So be selective…it is the only way to survive the Information Diarrhea Age.

73, Bob K0NR

Followup on 30 Dec:

I guess I should have specifically stated: I am finding value in Twitter….usually in the form of a pointer to an interesting web page or an insightful observation by one of the people I am following. Your Mileage May Vary.

Favorite Radio Videos

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As we head for the end of 2008, I am resisting the urge to do some kind of year-end retrospective. Instead, I’ll pull out some of the best amateur radio and technology-related videos on the web. OK, some of these were completed in earlier years, but this collection represents my favorite video finds on the internet.

Old Goat Field Day

Steve NØTU has captured a number of videos about his hiking / ham radio adventures with his two goats. This one is from Field Day 2008, operating from one of my favorite mountains: Mount Herman. If you like this one, check out Steve’s blog for other videos.

Digital Television Transition

This is a funny video about the transition to Digital TV (fasten your seat belts for that event, coming up in February 2009). It might be poking fun at the elderly, but it is also poking fun at the mess the FCC has created concerning this transition. Why can’t television be simple?

Mountain Dew Commercial with Ham Radio

This is a short Mountain Dew commercial with a reference to vintage ham radio in it.

“Radio Hams” Film

This Pete Smith movie is an oldie but goodie about ham radio….a trip back in time.

N2JMH PSYCHO ROVER

Operating rover in a VHF contest is a fun activity, one that I have been known to do. It does take a bit of a warped mind to truly excel at this….as shown in this video.

The Ham Band

This is a music video by by OZ1XJ and friends, with a ham radio theme to it. You gotta love the guys singing while hanging from a tower!

The Neighbors Find Out About The Ham Radio

This is what happens when the neighbors suspect you of operating a ham radio set.

Amateur Radio Today

This ARRL video with Walter Cronkite narrating is one of my all time favorites as it does a good job of telling the ham radio public service story. It is special to me since it includes coverage of the Hayman Fire….the biggest wildfire in Colorado history, which happened about 15 miles from my home

Investigating the D-STAR Modulation Format

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The D-STAR buzz continues to build in Colorado with a few repeaters on the air and more to come. For an overview of D-STAR, take a look at the article I wrote for CQ VHF magazine. I decided to dig into the digital modulation format that is used in D-STAR so I could understand it better. (Moving Forward!) At first, I figured that this newfangled digital modulation had nothing to do with FM but later realized that this is not completely true. (No, FM and D-STAR do not interoperate.)

It turns out that D-STAR uses Gaussian Minimum Shift Keying (GMSK), the same modulation format that GSM mobile phones use. What is that, you say? Let’s start with Frequency Shift Keying (FSK)…when the digital signal is a logical one, a particular frequency is generated. When the digital signal changes to a logical zero, a different frequency is generated. On the receive end, we just keep an eye on the frequency and decode the digital signal accordingly. In concept, we could generate this FSK signal by hosing the digital signal into an FM modulator. Minimum Shift Keying is a special case of FSK where the frequency shift (and the phase changes) are carefully controlled (modulation index of 0.5) to keep the phase discontinuities low and the bandwidth minimal. Add a Gaussian filter on the front end of this and you have GMSK. (The gaussian filter smooths out the digital transitions and gives an even narrower bandwidth.) I found this GMSK tutorial to be very helpful.

On the air, a GMSK signal has a constant amplitude, just like FM. It will switch back and forth between two frequencies as the digital signal goes high and low. The digital signal can be recovered using an FM detector but the output of the detector is the digital format.

Of course, GMSK is only part of the D-STAR modulation system. The other key component is the vocoder, which is the AMBE-2020™ Vocoder from Digital Voice Systems, Inc (DVSI). This chip performs the magic of smooshing the digitized voice signal into a reasonable number of bits per second so that when they are turned into GMSK they fit within the rather narrow bandwidth (6 kHz nominal). Since this vocoder chip is proprietary, it has caused some hams to grumble about the lack of an “open” vocoder algorithm. I think they have a point but it does get overblown. I have heard statements that this proprietary algorithm adds $100s to $1000s of dollars to the price of a D-STAR radio. My sources tell me the chip sells for about $20, a very reasonable price for this functionality.

I’m in the process of turning this investigation into my FM column for the Winter issue of CQ VHF, so there will be more detail there. I hope this short note gets your brain thinking.

73, Bob K0NR

Digital TV Transition

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The February 2009 shutdown of analog TV is approaching fast so I am actually starting to prepare for it. I previously wrote about this topic in Here Comes Digital TV. The FCC has asked the ARRL (really the amateur radio community) for help in getting the word out. This request emphasizes information sharing, not hands-on installation and troubleshooting of DTV systems. This is going to be interesting to watch….people that are served by cable or satellite are likely to be buffered from this change. The Over The Air User may have a different experience.

The FCC is pushing these settop converter boxes that allow people to convert their old analog TVs to digital. They will probably work fine for many people, especially if they have some technical knowledge. I really wonder about the less sophisticated consumers that are already struggling with their VCR and TV combo….now with a converter box in the middle of the system. “Let’s see, to record off the air I set the VCR to Channel 3 and the converter box to Channel 8 and then….” I am thinking there will be quite a few analog TVs headed to the trash heap. (Please recycle responsibly.)

An additional wrinkle that I just realized is that many of the VHF television stations are are moving to UHF for digital….but they will keep their existing channel designator. It turns out that the DTV system is defined such that the channel number that the user sees has nothing to do with the actual over-the-air channel that is used. For example, an analog TV station on VHF Channel 4 might move to UHF channel 35 for DTV but still be called “Channel 4” on the DTV screen. This is supposed to keep things simple for the consumer. This will work out OK if the consumer has a TV antenna that handles both VHF and UHF. However, in some regions VHF is so dominant, people may not have bothered with a UHF-capable antenna. They will have to make an antenna change to receive the new DTV signals.

In Denver it is going to be even more interesting. Channels 7 and 9 are starting out on UHF for their digital broadcasts and then will move back to VHF after the analog signals go off the air. This leaves them on their original VHF channel after the dust settles. So a viewer watching digital Channel 7 needs to view them on UHF Channel 17 right now, but it will be referred to as Channel 7. Later, their DTV signal will move over to the “real” VHF Channel 7.

This is going to be interesting.

73, Bob K0NR

Update 22 Dec 2008:

Take a look at this humorous video about the Digital TV transition:

http://www.wca.org/davidw/digitalconversion.wmv

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Moving Forward or Stuck in the Past?

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Are you moving forward or stuck in the past? This all started with a blog posting by Dan KB6NU appropriately titled I’m Tired of Pessimism. Dan basically said he has grown weary of the folks that specialize in displaying a negative attitude in ham radio. Jeff KE9V responded with a post of his own, writing:

The final determination of whether amateur radio remains an avocation of any significance will be made by those who actually enjoy the hobby. My advice for them on that fast-paced journey is to trample the slow and hurdle the dead lest they become bogged down by the rotting corpses of the “old guard” who refused to change.

This reminded me of one of my postings from January, titled Paul Rinaldo’s Rule of Amateur Radio Progress, which related some words of wisdom (not mine):

Progress is made in Amateur Radio by letting energetic individuals move forward. Conversly, nothing in Amateur Radio is accomplished by complaining about other individual’s projects. Simple summary: If you don’t like their project, then go do or support your own choices. Get out of their way.

Note the common theme of lead, follow or get out of the way but don’t be the curmudgeon that spoils everyone’s fun. If you have spent much time with me, you would know that I can get as cynical as the next guy. I specialize in sarcasm and can derive great satisfaction from pointing out the errors in other people’s thinking and actions. The only problem with cynicism is that it doesn’t accomplish anything beyond generating that smug feeling of being right. It doesn’t move anything forward — it just complains loudly about the situation.

The older I get, the more I try to avoid the easy out of that soothing cynical attitude. For me the test is simple: does an attitude/statement/question/action move things forward or keep the situation stuck? Things that move forward have value; things that keep us stuck are worthless. See Paul Rinaldo’s comments.

Lately, I have been applying the Moving Forward / Stuck in the Past Test to ham radio activities. I flip through the ham magazines and I see quite a number of articles on vintage radios. Moving Forward? I don’t think so. How about AM operation? Stuck in the Past. Ham radio connected via the internet? Moving forward. Sound-card digital modes? Moving forward.  What about CW operation? (Be careful here.) I actually think this one is Moving Forward. Why? Because CW still represents an extremely efficient operating mode in terms of bandwidth usage, simplicity of equipment and versatility. I can do a lot with just a simple QRP rig and my brain on CW. (I know some of you will argue that it is Stuck in the Past and you might be right.) Radio amateurs that are helpful Elmers? Moving Forward. Grumpy old men that look down on newcomers: Stuck in the Past.

Now there is nothing wrong with Stuck in the Past activities….as long as they don’t get in the way of Moving Forward. I know some guys that get great pleasure out of running their old AM rigs on HF. I am glad they are having fun with it. But we don’t use up all of the 20 Meter phone band running such an inefficient mode….we keep it to a few frequencies.

So where are you: Moving Forward or Stuck in the Past?

73, Bob K0NR

My Tweaks to the Aspire One Netbook

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I need to document the tweaks that I made to the Acer Aspire One netbook, so I figured I might as well post them here since someone else may find them useful. All of this info is available with sufficient googling but here’s the condensed version.

Background

The PC is the Acer Aspire One, Linux  version with 8GB SSD, referred to in these previous postings:

https://www.k0nr.com/wordpress/archives/200

https://www.k0nr.com/wordpress/archives/430

My basic approach to hacking this PC is to leave most of it alone and make minimal adjustments:

  • Enable the advanced mode user interface
  • Load Thunderbird in place of the original email client
  • Load a few more games

Enable Advanced Mode

This one is easy. Get into the Terminal mode (AKA linux command line) by pressing ALT – F2 on the keyboard.  Type in: xfce-setting-show which will bring up a window with several icons on it. Click on Desktop to get to the Desktop Preferences and choose the Behavior tab. Now mark under Menus the Show desktop menu on right click option and close the window. Now you can access a much expanded menu selection by selecting a Right Click on the desktop.

See http://www.aspireoneuser.com/2008/07/09/aspire-one-advance-linpus-mode-hack/ for more information or if you find my instructions inadequate.

Load New Software

Now that Advanced Mode is enabled, we’ll go load up some new software. Do a Right Click with the mouse on the desktop to bring up the advanced menu. Select SYSTEM and ADD/REMOVE SOFTWARE, which brings up the dialog box for managing the installed software. It will probably take a little while for it to load the list of available choices. Then use the SEARCH tab to find these software programs and add them in:

  • thunderbird
  • any other programs (I just added a few games)

Follow the prompts to get the software to load and be patient.

Fixing the Main Menu (So Email points to Thunderbird)

There is one more thing to fix. The Desktop Menu icon for “Email” still points to Aspire One Mail, not Thunderbird. You could choose to just live with this and select Thunderbird from the Advanced Menu (Right Click on Desktop). Warning: You can royally screw up your computer if you make an error, so all disclaimers apply!

To change the Desktop Menu, we need to edit one of the files that defines how the menus are configured. This forum discussion has all of the info but I will also summarize it here.

Edit this file using Mousepad or some other editor:

/home/user/.config/xfce4/desktop/group-app.xml

You should be able to use the standard file manager to find this file. A double-click on the file should launch the editor.

Find the line that begins <app sequence=”3″ acs=”email”>
Change AME.desktop to mozilla-thunderbird.desktop
Save the file and reboot the PC (you may want to save the original file somewhere in case you need to reverse this edit). Be Sure to Reboot the PC for this change to take effect.

One More Thing
To stop Aspire One Mail from checking for new messages:

Open Aspire One Mail (you may need to use the advanced menu now for this)
Tools>Options
Uncheck: “Check for Messages Every:” and “Play sound when new messages arrive.”