Friday, September 19, 2008

Where's David?

Been a while since I posted. Most of the summer was spent doing various projects; some for pay and some for fun. One of my new interests is APRS - Automated Packet Reporting System. It started when a ham friend of mine decided to hike the John Muir Trail and wanted me to keep in touch with him and his girlfriend as they hiked. He carried a Kenwood TH-D7A(G) APRS handheld; so I decided that I would set up APRS to track him.

In the process of doing this I learned a lot about APRS and the mechanics of routing packets through RF. I set up an "I-Gate" which is a system that passes received RF packets into the APRS servers via the Internet. Turns out this was quite useful to some local hams that carried Kenwood TH-D7A(G) APRS handhelds which could not normally reach the mountain-top APRS repeaters aka "digipeaters". So now my station's running 24/7; not great for keeping the electric bill small but I guess that's why I have a 3 KW solar PV array on my roof, yeah?

In exploring APRS I learned that when it comes to digipeaters "more" is not necessarily equated to "better". RF packet is about passing packets to the target (or targets) with little (or ideally no) redundancy. For the most part we enjoy a great VHF environment here in the Bay Area; the Silicon Valley is ringed by mountain ranges which provide line-of-sight at nearly any time to at least one of the wide-area digipeaters. Any additional digipeaters are redundant and therefore create extra packet traffic. (The exception to this is of course low-level/low-power "fill-in digipeaters" designed to serve small pocket valleys, urban canyons, etc.) With a dense population and a lot of hams using APRS it's a constant battle to keep the 144.390 MHz APRS channel from becoming too crowded. I-Gates don't contribute to the crowding problem; that is if they're set up as receive-only I-Gates.

I'm having a good time with APRS; besides just being able to track locations I've also been exploring how it can be used for text communication; I had a nice QSO with YB2TJV in Indonesia recently. It's also proving useful to study VHF propogation in the area. I have no idea why my callsign was used by OH7LZB as an example in his blog post on the new I-Gate coverage function on; but I was flattered anyway!

I'll be hosting a forum on APRS at Pacificon 2008 which runs from October 17th - 19th in San Bruno, CA. My forum is scheduled for 8:00am Sunday the 19th; if you're in town please do come by and say hi!

Thursday, May 29, 2008

Tech Note: Radio Shack Pro-2018 Scanner

I recently purchased a cheap radio scanner to replace my venerable I recently purchased a cheap radio scanner to replace my venerable Electra Bearcat 250. I bought a Radio Shack Pro-2018 (catalog # 20-424). Reading through the Radio Shack website a few days ago I was amazed to find that they were selling the programming cable for my scanner for 97 cents!? The cable (catalog # 20-429) is being discontinued, apparently. I found a store which had one and picked it up.

Radio Shack also offers a free programming software package. It is quite frankly one of the lamest applications I've ever seen; an absolutely horrid GUI and it would only import from DBase III format (.dbf) files. A quick Google search revealed an open-source scanner loader application "ProLink" which looked promising. It doesn't specifically state support for the Pro-2018 but it does support the Pro-2017 and the Pro-79 which are (from a serial port interface perspective) the same.

The nice thing about ProLink is that it can open text and CSV files, so creating a frequency list from copied text is fairly easy. I used Excel, and copied a lot of data from and K6SCC's page. Caveat: Apparently most of these low-end scanners don't have a download function. So don't expect to use ProLink to download the painstakingly-created frequencies you may have already on your scanner.

I ran into two small but annoying glitches which I'd like to share. One glitch was that when I initially tried to open my CSV in ProLink the application would lock up and require a process-kill. I knew the application could open CSV files because it successfully opened a sample file included with the application install. Examining the good vs the bad CSV revealed that Excel did not maintain all of the commas and quotation-marks around text which apparently ProLink expects. So I had to open the CSV in a text editor and manually reformat the file. Thank you, Bill Gates.

The second glitch was in trying to get the serial interface to work. Turns out the I needed to reconfigure my USB-serial dongle for the following config: 4800-8-N-2 (4800 bps, 8 data bits, Parity=None, 2 Stop bits) and Flow control set to "None".

Once I did this the data file loaded into the scanner no problem. I'm not sure I saved any time doing it this way, but at least now I know that I have a soft copy of my frequency list and should I need to make any changes I can do this in the file and then reprogram the scanner.

Tuesday, May 6, 2008

Wireless at Maker Faire 2008

Last weekend my wife went on a short trip with some friends, leaving me home to try my hand at single fatherhood. Still, I managed to get away from my "Mr. Mom Weekend" for a few hours on Friday and Saturday nights (paid a babysitter on Friday, and cajoled my mother-in-law into service on Saturday). On Friday I attended the PAARA amateur radio club meeting in Menlo Park, and on Saturday I drove up to the Maker Faire in San Mateo. The role of wireless technology at the Maker Faire was very evident, but not in the way you might expect. For the uninitiated; the Maker Faire is a combination of Burning Man + science fair + flea market. People come to show off their contraptions and creations; robots, alternative fuel vehicles, lots of stuff which uses embedded controllers, and (especially after the sun went down on Saturday) enough fire and explosions to satisfy even the most ardent pyromaniac. The highlights for me were:
The contrasts at the Maker Faire are numerous and glaring. The parking lot is filled with hybrid cars, and the usual "Impeach Bush"/"Obama 2008" bumper-sticker polemic you expect to find in the SF Bay Area. So you'd think the Maker Faire would be focused heavily on eco-friendly and minimal carbon footprint exhibits. And yes, there were a huge number of exhibits showing off renewable energy and transportation technology; solar, wind, algae-fuel, bio-diesel, electric motorcycles, pluggable hybrids, etc. But after sunset there were also many combustion exhibits and shows using propane, kerosene, lamp oil, etc. The smell of incompletely burned hydrocarbon was everywhere, as tongues of smoke curled up against the deepening sunset in the chilly evening air. How to reconcile this? I don't know that I can. Is the Maker Faire a neutral zone in the global warming debate, a sort of United Nations of carbon consumption? Or is this yet another example of hippie hypocrisy? Best if we leave that one to the philosophers.

If you're still reading, you might be wondering how this all relates to wireless. It does, and thanks for sticking with me as I get around to that. Wireless technology of all types was very evident and widely used at the Maker Faire, but the operating word here is "used". There were no exhibits (that I saw) which showed off anything related to innovation in the wireless space. There were a ton of people using Wi-Fi, Bluetooth, proprietary ISM data-link radios, radio-controlled servos, etc. Wireless was everywhere, but in all cases it was "user wireless"; projects created with off-the-shelf modules and in some cases chipsets. Wireless is a tool to complete projects, not the project in and of itself. I find that this echoes a growing trend I've observed at the WCA and in the wireless industry as a whole: Put plainly, wireless technology is becoming a commodity.

Some of the hams from PAARA set up an amateur radio special-event station to make 20m and 2m/70cm contacts from the Maker Faire. I never found this exhibit, but a few people on the N6NFI repeater say the station had to contend with some bad RFI; which I can imagine given that a giant Tesla generator was operating nearby. I'm quite sure that most of the Maker Faire was essentially a gigantic FCC Part 15 violation.

It's unfortunate that the hams did not have a bigger role at Maker, because amateur radio has its roots in innovation and home-brewed technology; ham radio is a great-great-granduncle of the Maker movement and should rightfully hold a place of honor and respect in the Maker community. I think that the problem is that a lot of amateur radio has become consumerized and is now ironically an example of the "culture of learned helplessness"; ironic because the technology consumerism which is the fastest growing segment of amateur radio (i.e. people who chose to buy versus make) is at odds with the hacking/creation/innovation core elements of the Maker movement.

The amateur radio community still certainly has a lot to say about innovation and technology; the huge number of hamfests, tech days, field days, DXpeditions, etc is evidence of this. The problem seems to be that amateur radio events have become somewhat insular; we're doing events for ourselves, and not reaching out as much as we should to non-hams. By way of example; this month's AM-TECH Day is on May 10th. Past proof shows that it will be popular, or at least popular with hams. Wouldn't it have been better to push AM-TECH up a week and hold it at the Maker Faire? How many Makers could we have licensed if we'd held AM-TECH and a VE test session a week earlier at the Maker Faire?

I also think that we need to seriously rethink our approach to new technologies. Hams are spending way too much energy on "maintaining the tradition" in modes of operation such as CW and voice, and not exploring how amateur radio might benefit from integration with other technology. I think radio amateurs still have a lot to offer the wider technical community, but we need to reach out and open our doors. This means far less worrying about nurturing traditions and whining about the evils of no-code HF, and a lot more mold-breaking. The concept of the Maker Faire and amateur radio is to hack, to repurpose, to change forms and function. We can learn a lot from the Maker community, and they from us. How do we make this happen?

Friday, March 21, 2008

$20 Billion dollars later [700 MHz auction]

Article from InformationWeek which talks about the 700 MHz spectrum auction. (Verizon, AT&T Big Winners In 700 MHz Auction) I'd been hearing projections of between $15-$20 Billion; so this tracks with expectations.

The point I think nobody has yet addressed is "what will happen to all the money that didn't win the auctions?" Presume that in total the amount of money which smaller players had available to bid was equal to the amount that was bid by the winners. This is a conservative estimate; in fact I suspect the number is larger. So that means that as of yesterday there's $20 Billion dollars sitting around which must now be re-purposed.

Let's look at this in perspective... The worldwide semiconductor market is approximately $200 Billion dollars. The entire worldwide electronics industry is approximately $1 Trillion dollars. Presuming that all of the unspent bidding dollars are put back into technology; this means that the worldwide electronics industry as a whole grew yesterday by 2%. If my suspicions are well-founded, it could in fact be greater than 2%.

So...where's the money going to be spent? What's if anything is the net effect on the technology markets?

Wednesday, February 27, 2008

The Sound of Silence

Last November we drove down to Disneyland in my wife's van, and I wired up a VHF/UHF rig and mag mount for the trip. Ever since the phone systems failed due to overloading during the relatively minor October 2007 Alum Rock quake I've been nervous about relying on cellphones in emergencies. I spent some time researching repeaters along the route, and more time programming everything into the radio.

All for naught, apparently. During the trip I was struck by the almost complete lack of traffic on every repeater I tuned in. It wasn't a problem with my equipment; there just wasn't anyone on the air. Even in the densely populated Los Angeles area, the entire twelve hour trip was mostly a never-ending chain of silence. The most traffic I heard was on linked systems such as the Cactus Intertie and the WinSystem, but that's to be expected because they have dozens of connected repeaters and all it takes is one person talking somewhere on the system to light them all up.

On my base and mobile rigs I have a lot of local repeaters programmed, ready to go. And yet at any given time; nobody's talking. Pick up the mic, announce "W6DTW monitoring".... and listen to silence. Reminds me of the This Week In Amateur Radio "Random Access Thought" segment by Bill N2FNH about a repeater that died when a spider crawled across a circuit board; shorted himself across a resistor; killed the repeater...and nobody noticed. And yet; try asking your local frequency coordination council for a frequency pair and you'll get told "there's nothing available". The howling wind of silent FM static is blowing through most of our local repeaters just as it was through the repeaters I tuned into on the trip to Southern California. So how is it that all of the frequencies are spoken for..?

Things are not much better down in the HF bands, or perhaps I should say not much better in the legal HF bands. Given that we're currently coming out of a low point in the 11-year sunspot cycle you might be tempted to allow that the amount of traffic will be low. Especially in the higher frequency bands like 10 meters, where popular wisdom says there's little propagation during the day and certainly none at night. So the 40 and 20 meters bands have some traffic (mostly contesting), 17 meters opens up around noon for a while, and we're starting to hear folks on 15 meters. But for the most part; few stations are on the air and silence above 21.5 MHz is the rule.

So then why is it that on any given weekend day, if you listen above 27.405 MHz into what's been termed the Freeband, you'll very likely hear a lot of traffic? I hear strong stations coming in from around the Western US and Mexico. Is there something odd about propagation that creates a difference between 27.915 MHz (aka the freeband "Redneck Skip Calling Frequency") and 28.400 MHz (aka the amateur "10 Meter Calling Frequency") so that one is active and the other not? Surely the Freebanders don't have some kind of secret technical prowess that allows them to punch through where amateurs cannot? The reality is likely that amateurs simply don't believe that there's good propagation without sunspots, so they don't tune in and "no propagation" becomes a self-fulfilling prophecy.

I find it amazing that while the great swaths of spectrum which amateurs can legally use sit idle; another group of people who are sometimes called "pirates" (agree or disagree with the term as you wish) are happily making use of frequencies which are right next to a band that amateurs will effectively ignore for a good 25%-40% of every sunspot cycle. Yes, Freebanders are operating illegally according to FCC regulations. No, I'm not a Freebander. However; I do have a sense of respect for them. They are (from what I can see) more enthusiastic and aggressive about pursuing the hands-on technical aspects of radio than many hams. They're out there modifying radio equipment on their own---which they have to do because there's no legal way to buy freeband radios. They're not sitting around waiting for sunspots to come back so they can get good propagation; they get on the air and take what the sun gives them on that day.

That's real radio.

Monday, February 11, 2008

Expensive Desktop Mic Get Pwned By $12 VOIP Headset

A while back I purchased an entire amateur radio set from a ham who was getting out of the hobby. A rare occurrence, mind you. I really only wanted the radio (a Yaesu FT-1000D) but the guy sold me everything except the feedlines and antennas for less than I'd expected to pay for the radio. Everything worked as expected. In the plethora of boxes I lugged home were a lot of accessories; among them a West Mountain Radio RigBlaster Pro.

The RigBlaster sat in storage for almost a year, until recently when I watched K7AGE on YouTube talking about his homebrew Bluetooth headset interface. One of the accessories which came with the FT-1000D was a Yaesu MD-100A8X desk mic. I've frankly been less than pleased with performance of that mic; it's very sensitive to any change in sound level due to distance from my mouth which means that keeping the FT-1000D's ALC from kicking requires that I constantly ride the PA drive control--and that's tough to do when I'm focused on maintaining a constant mouth-to-mic distance. So I started thinking about getting a headset. Of course, you can spend a ton of money on a "good" headset; e.g. Heil Sound is the name in radio mics and headgear and their stuff starts over $100 and goes up from there. Being the cheapskate I am I decided to experiment with a $12 General Electric VOIP headset I got from Target to do Skype while I was traveling through Asia in 2006.

Interface to Yaesu was a snap using the RigBlaster. As with most amateur radio accessory companies, West Mountain Radio's website and manuals are poorly written but I was able to decipher them enough to set the jumpers properly for the Yaesu. Most computer headsets are have electret voice elements which require a 5 VDC bias on the ring terminal; the RigBlaster can provide bias on the MIC2 jack which also happens to be the perfect size for a PC headset plug. I didn't bother to route any of the receive audio paths; for now I just have the receive side plugged into the headphone jack. I have the MD-100 plugged into the RigBlaster--just in case--but its primary function now is to act as a PTT switch.

The results were impressive. I checked in to the 75M late night net and got an unsolicited report of "great sounding audio" from W6EZV. A flattering report, considering that the 75M late night guys are used to hearing perfectly processed and equalized audio from people like W6OBB aka Art Bell. I'm now able to operate with both hands free, and the headphone has an added benefit of making sure the receive audio is not bothering my family after they've gone to bed. My audio settings are a lot more consistent and don't require constant fussing with the PA drive and speech processor levels. Best of all I'm no longer inclined to go out and spent hundreds of dollars to get a high-end Heil headset. I'm now curious to find out if my successful experiment is unique to this particular VOIP headset or if I can get the same results with other brands.

Sunday, January 13, 2008

Pimp My Rig

During the recent severe storms we lost power at home a few times. I had my radios on battery power monitoring various emergency frequencies but at times I was struggling to read some of my equipment with non-backlit displays. A small LED flashlight worked well in a pinch, but afterwards I started to think about how I might improve the lighting at my station without using wall-socket power and/or consuming a lot of my station's reserve battery power.

The answer came to me while I was wandering around a Target store. There's a company called WinPlus that makes a line of auto accessories under the brand name "Type-S"; they offer a lot of dashboard gizmos, LED map lights, gadget holders, etc. Their stuff is actually quite well-conceived, for the most part. One of the items they sell is a "Dash Mood Light Set" which consists of two small "LEDs in a barrel" with 3M adhesive-backed swivel-mounts and a "cigarette lighter" accessory plug. Setup was very simple; all I had to do was plug in the lights (using an accessory socket) and stick the swivel-mounts on the radio faceplates. The lights draw less than 10 mA of current and provide great illumination of the displays even in total darkness. The wires are very slender so I was able to tape them down with black electrical tape and now they're essentially invisible.

Friday, January 4, 2008

What a day....

So today was quite a day. The stock market (and my 401k) tanked on job data and high oil prices. Britney Spears got carted away for observation at a mental hospital after a standoff with police. And the Silicon Valley got slammed by a major storm that toppled trees, knocked over my backyard fence, ripped the roof off of our rental property (complete with flying roof tiles smashing a car window in the process), and bending my Comet CHA-250BX antenna. I'd probably be more upset by all this (except the Britney Spears part) if not for the fact that I'm sick as a dog right now with some kind of nasty virus.

I'm hopeful that the amount of misery in any given year is limited and that I'm getting all of my ick for 2008 out of the way early.