I’m on a local ham radio mailing list. (Though I’m actually not sure how this came to be.)
So a few neat links. The first is a yagi for 160 meters. Antenna size is inversely proportional to frequency, and 160 meters is the lowest ham radio frequency out there. The notion of a 160 meter yagi is almost obscene. You can just barely make out that there are two people working in the antenna.
There are also photos as a neat site called Artificial Owl of the former Russian Woodpecker, a Cold War-era “over-the-horizon radar” meant at detecting incoming missiles. It’s rumored to have transmitted as much as 10 million Watts (ERP), spewing interference all over the HF/shortwave bands the world over.
You know those times when you decide to let yourself surf aimlessly? And an hour later, you have absolutely no idea how you got to where you did?
I found the K0S Strange Antenna Contest page from 2003, where some ham radio operators started using, well, strange things as antennas. Who’d think that a ladder works well? (No no, not ladder line, but an actual ladder.) In fact, after working some people off of a ladder, they got an even better idea, and stood several ladders up, using them to support a pair of extension ladders laid horizontally, forming a ladder dipole, with impressive results. Sadly, they report that combining two shopping carts to make a dipole did not get them any contacts, nor did a basketball hoop.
This has me wondering what else would work… An aluminum chain link fence? A railing? Train tracks? Power lines? (Kidding on that one. Please do not try to attach anything to power lines.) Curtain rods? A couple of cars? A section of guardrail? A metal lamppost?
I poked around the site some more, to see if they did it in subsequent years. And they did. 2004, for example, saw my joke about using two cars come to fruition. (Okay, so they beat me to it by four years.) 2005 saw someone use a bronze statue, and, the next year, he was at it again with railroad tracks, albeit not full ones, but some sort of art exhibit / monument. (Aside: I’m pretty certain that trying to hook up a bunch of wires to train tracks may arouse a bit of suspicion by the police?) 2006 also saw a pair of exercise machines being used, with a comment about how they weren’t very effective, but the apt comment, “On the other hand, we did in fact make two contacts with a pair of exercise machines standing only a few inches above the earth!” And, confusing everything I know about antennas, someone used a tree. And a football stadium (which includes a commentary about how the university police were initially slightly suspicious about someone getting out of their car and hooking wires up to the stadium for some reason). 2007 saw a bridge as an antenna.
And 2008? Well, see, here’s the best thing. The 2008 Challenge is this weekend!
Of course, as a Technician-class license, I don’t have many HF privileges… The Technician license was (before all license classes saw it eliminated) the only class that didn’t require a Morse code exam, so it’s somewhat ironic that almost all of the new HF privileges Techs were given are in the CW portions of various bands. I do get 28.3-28.5 MHz now, allowing SSB on HF…
Time to hit the books, I think. (I think mine–and that one–might be outdated, actually. Looks like the question pool got revised in 2007.) There are always sample exams online, and the feedback can be helpful. Study a bit and take an exam a day, and then review your answers. (Theoretically, actually, you could just learn the answers to each question without understanding the concepts, though that’s really missing the spirit and point of ham radio.)
There were a couple people screaming profanities outside my window. After about ten minutes one of them shouted, “Come drink with us” at some girl, and I looked out and saw that they had beer bottles.
Sufficiently irritated at this point, I called Campus Police. The dispatcher said, “I just sent someone up that way for this,” so I turned on my radio.
Sadly, the officers had the wrong location and missed them. But I was observing the whole thing through my window listening to them. I had to find a way to call back without divulging that I was listening to them, so I just stated that I’d seen the officers look in the wrong spot and leave. She asked me for a better description of their attire, in addition to my exact description of their location. I watched a couple cops slowly approach, observed the people I’d called about, and swooped in.
At this point I expected the students to stop yelling, apologize, and be asked to move back into their room. Instead, one of the students, upon seeing the police, threw his bottle down, screamed, and took off, with the second kid following him. The officers initially chased them into the woods.
One officer stopped chasing them as they got into the woods. I was slightly disappointed to see them get away, except that all I really wanted in the first place was for them to stop yelling profanities and derogatory comments at people. So I was happy.
But I was even happier when another officer radioed in that he had seen the kids come out of the woods and was picking up the chase.
At this point my batteries died, so I’m not yet sure how this ended. But suffice it to say that it ended up significantly more interesting than I’d initially expected. And the drunken jerks are gone.
As an aside, the school’s 100W repeater (into a high-gain antenna, it seems) seems to overload my poor little VX-2. I tried enabling its attenuator feature, but it still didn’t seem to cut it. I then tried removing the antenna, but then the signal was too weak. (Although still audible.) My IC-W32 holds up much better to the overwhelming nearby signal, but its batteries don’t. And my ASTRO Saber is entirely unphased by the signal, but its batteries died the other day and I hadn’t recharged them…
There are a few different technologies commonly used in two-way radio. One is digital voice, a la Motorola ASTRO / Project 25’s CAI (IMBE), which is a 9600bps (9.6kbps) digital stream. Another interesting technology is trunking: a city might have 12 talkgroups (think “virtual channels”), but only 4 frequencies. One frequency is designated as a “control channel,” which is a digital stream announcing system status. When you want to transmit, your radio will go out to the controller and get assigned one of the frequencies, and the system will then announce that you’re transmitting on one of them, and all radios in your group will switch over and listen. This allows much greater spectrum utilization: rather than needing a new frequency for every group that might want their own channel, you just need to license enough frequencies for however many simultaneous conversations you expect.
I’ve been thinking that it’d be interesting to merge the two technologies. Technologies like Speex will let you process audio at exceptionally low bitrates, seemingly as low as 3.4kbps. (And they have some neat technology, like variable bit-rate encoding and even further drops in data transfer in between words, dropping quite low for when it’s just background noise.) So I think it’d be neat to start a “data network” at 32 kbps, which could be done with relatively low bandwidth. You could keep one frequency, and yet fit as many as 7 or 8 simultaneous conversations on it. (And you can take its VBR support one step further, and have it scale to fit system capacity: on a system with minimal activity, allow 8-16 kbps, but when the system is starting to fill up, drop down to 4 kbps.) HE-AAC (also known as AACPlus) looks promising too, although it’s a proprietary technology.
And since it’s now a 100% data network, you can do what I’ve always thought mobile radio systems, especially those used by public safety agencies, ought to do: put a GPS unit in each radio, and have them embed GPS coordinates in each transmission, as well as periodically announcing their coordinates in the background.
The net result is insanely efficient (radio) bandwidth usage. For example, Boston PD has 16 frequencies licensed, but it’s rare for more than 2 or 3 to be in use at any given moment. They could get more efficient by switching to a trunking system, maybe with 5 frequencies (plus a control channel). Of course with an established system, there’s really no incentive to, but I digress. But if they could get entirely usable digital audio at 3-8 kbps, they could actually move to a single frequency and support multiple, simultaneous conversations.
Another neat side-effect is that linking the systems would get quite easy: the entire system, with multiple conversations, could even fit over a single dial-up modem link. And you can have better “emergency” support, although most trunking systems seem to do it anyway: public safety radios carry an “orange button,” which will signal an emergency to the radio system. Analog systems do this by basically making the radios “obnoxious”–they’ll just keep transmitting a distress signal over and over, increasing the odds that they get through. With an all-digital system, they can just send packets indicating an emergency, and have the network make way for them, going so far as to terminate existing conversations if needed.
Oh, and another novel benefit is power management. If I’m on a handheld radio and I’m standing twenty feet away from the tower, I can dial my power down as low as it goes and still make it in fine. But if I’m a few miles away, I need to be using the highest power I can to make sure I’m making it. Of course, no one in the field fiddles with power settings. (In fact, most radios don’t make this something the user can do.) But if you just exchange a bit of signal strength info in the data flowing between radios, you can make this automatic. As I talk to the tower, it’ll be periodically confirming that it’s hearing me. But when it does that, rather than just using a boolean, “Yup, got it,” it can send me signal strength data, and my radio can dial down power until it’s at a, “I’m still getting 100% of your packets but I wouldn’t go any lower in power…” point. The net result is longer battery life. (And potentially, less interference to distant users of the same frequency.) As a really obscure benefit, if you’re transmitting this information, and also embedding GPS coordinates in your transmissions, the system could silently log all of this and generate coverage maps, which would get more and more detailed over time.
So my building here is one in a “set” of three dormitories. There’s a walkway, and another building on the other side of it. (And the third is to their side.) As I came back from class, I noticed a rope running from a room on the floor above mine across to the room pretty much opposite mine. It was extremely nice out today, so even those of us not creating improvised clotheslines (?) had our windows open.
We took a partial interest in whatever they were up to, but mostly about our business, just periodically looking to see what they were up to. We could also hear everything they were saying. So I sat at my desk working on something or other, when I heard a “roger beep.” I instinctively knew that it was from an FRS radio. It’s one of those silly noises they make at the end of a transmission. (As compared to things like MODAT [.wav] or MDC1200 [.wav], which are useful for ANI.) I’ve only ever heard it on FRS, so I “just knew.”
Of course, merely thinking, “They must be using FRS” because of a sound I overheard wasn’t geeky enough. So without missing a beat, I picked up my ASTRO Saber and switched to the “Zone” I’d created for the FRS band, and threw it into scan mode. A couple minutes later they transmitted again, and the scan stopped on Channel 2. Sadly, they didn’t discuss the actual purpose of the wire, only the difficulties they were facing on one of the ends.
It was tempting to radio back, “What exactly are you guys doing?,” but I didn’t want to blow my cover just yet. And besides, this thing puts out five Watts, ten times the power allowed on the band. (And the deviation/bandwidth is probably wrong, and it’s not type-certified…) Oh, and I think I probably have it set up to send an MDC PTT-ID.
It really concerns me how my mind works sometimes.
So the Project 25 protocol, with its IMBE CAI digital voice, is being rolled out in huge numbers. Motorola’s ASTRO is the most commonly-used, although several other providers make radios that do the P25 standard, too.
They’re calling it interoperability. When you and the next town over both buy $3,000 radios doing a crappy 9600bps digital audio protocol, your radios can talk to each other! I’m really not sure who fell for this, since the existing strategy, analog voice, worked 100% of the time. They’re switching people over to a new, proprietary (kind of: the voice codec is proprietary, but it’s part of an open standard) digital system so that everyone’s radios can talk to each other. This has never made sense to me.
The other big problem is that there are multiple bands out there. In New Hampshire, VHF is most common. You’ll find police, fire, and ambulances between 152 and 161 MHz. (More or less: they expand a bit on both sides.) Massachusetts is big on UHF, with the police usually being between 460 and 490 MHz. But it’s not quite that standard–some municipalities do their own thing. The 800 MHz band is becoming big, too, especially with trunked radio systems. You find that a lot in big cities. (Indeed, I think Manchester and Nashua are on 800, though I don’t monitor either so I wouldn’t swear to it.) And now there’s a 700 MHz band coming out that’s slowly being introduced.
As a ham, we have allocations on VHF and UHF that are both very common: 144-148 MHz and 420 or 430 through 450 MHz. Since both are commonly used, a lot of ham radios will do both bands. So my ham radios merrily transmit on both VHF and UHF. But, for whatever reason, this never caught on with “commercial” radios, like the ones public safety agencies use. If you want your police cars to monitor VHF and UHF, you put two radios in them. God forbid you work for something like a huge city, or a regional task force, where you may need to communicate on VHF, UHF, and 800 MHz. That’s three radios everyone will need to carry.
Vertex (the “commercial” branch of Yaesu, a ham company) made a dual-band radio. Once. The FTH-2070 came out in the 80s (?) and did VHF and UHF in one radio. It was huge, but for people who needed both bands (lots), it was a huge boost. For some reason, no one ever made a radio to follow in its footsteps, and the radio hasn’t been made for several years.
So it’s actually a grand mess. You have four different bands that a public safety agency may be on. They might be using analog voice, or they might using digital. (And this isn’t even counting wacked-out proprietary standards like OpenSky / EDACS / SmartNet, which are all additional technologies that need their own radios.)
Finally, someone saw the light. Thales has announced The Liberty, a handheld that supports P25 digital (and, of course, analog voice), and covers all four major bands. Pricing is rumored to be around $5,000, but you have to keep in mind that it’s doing the job of four radios that would probably cost $2,500 each. It’s SDR-based, front-panel programmable, and supports several different encryption protocols as well.
Thales previous filled a bit of a niche market. It looks like they do a lot of government stuff, and I seem to recall them being bigger overseas (but maybe I’m confusing them with another company). But this radio has a lot of high-end radio afficionados over here drooling. They not only did a dual-band radio, but they did a multi-band radio. It’s got a big color screen. (What the functionality is remains to be seen.) I think a lot of people, not just me, are hoping that this will lead to more competition, which will lead to more innovation.
I’m a long-term radio geek, and I’ve realized that the technology interests me more than actually using it. Having worked with lots and lots of radios (I realized that I have three sitting on my desk, all of which I have used in the past 30 minutes), I’ve concluded that I’d like to start a radio company. Our motto would be, “Our radios don’t suck.”
One of my radios is a ham radio, which is front-panel programmable (FPP), meaning that you can punch in frequencies on the keypad. This is pretty common with ham radios. By contrast, land-mobile radios (things that, say, a police officer would carry) very rarely have FPP capability; in fact, the FCC frowns on certifying radios with that capability, except for certain federal agencies that need to be able to reprogram their radios in the field. However, it’s often offered as a software add-on. But even using the ham radio, it’s really hard to use. Part of the problem is that the radio’s probably a decade old, and the print on the keypad has worn off. So I’m guessing at what buttons do.
There are very few radios with a graphic LCD. Dot-matrix LCDs almost seem cutting-edge in the radio world. By contrast, try to find a cell phone that doesn’t have a big color LCD on it. I have an old Garmin GPS III, and still admire that screen. I think it’s four shades of gray, and fairly high resolution. It’s a nice graphic LCD. It’s so much easier to use, and introduces stuff like the ability to “arrow” around a screen, as opposed to trying to use obscure key combinations. I’d actually love to see something like a 2″ by 2″ e-ink display (which, in addition to looking amazing, would reduce power usage), but it’d be a pain since it’s slow to redraw.
Motorola’s MDC1200 technology is practically ubiquitious in the public safety industry, transmitting a 1200 bps data burst containing a four-digit identifier. This could be so easily improved. Put a little $20 GPS chip in it, and have it transmit GPS coordinates on each transmission. (You could also include stuff like battery level, if on a portable, and information on received signal strength. The latter would be useful to run in the background and plot a map of the radio system’s reach.)
Programming is always a pain. Some of Motorola’s radios are programmed in ways that are so obscure that they border on comical. (I think the goal there is security.) I want to write an XML file for my radio. Put a USB port on the side of the radio. Let me hook it up to a computer, or just plug a thumb drive in and reprogram from that. But consider bigger problems, though. Boston PD switched to an “improved” channel lineup last year. Apparently they worked for weeks to pull radios in at the end of a shift, load up the new set of data, but leave the radios set to old configuration, until all the radios had the new programming in them. And then, at a quiet time one day, they broadcast a message telling officers how to switch to the new configuration. Over-the-air programming is possible, but it’s generally used in some specific situations. (OTACS, Motorola’s Over The Air Channel Steering, to direct a radio to switch to a particular channel, and OTAR, Over the Air Rekeying, to send new encryption keys to the radios.) Why not let the system send out bursts of programming data when the radio system is idle, loading up new programming data in the background, until they’re ready? Obviously, all of these programming things need some security constraints, but that’s trivial to implement.
I’m pretty confident that software-defined radio is going to become ubiquitous in the next decade, but no one’s really making use of it yet, except for uber-geeks in labs. APCO’s Project 25 digital voice (IMBE) has emerged as a standard in digital voice, but it’s meant to be made obsolete in the future by a “Phase II” implementation. Various other technologies have come and gone, such as Motorola’s VSELP. And there exist myriad trunking protocols for larger networks. I want to embrace SDR and use it in everything, “future-proofing” radios. (Of course companies have an incentive to not future-proof their hardware, forcing people to upgrade… But you can still make your money on selling software upgrades!)
Oh, and put an SD slot on the darn thing. Record the audio it receives, letting people play back transmissions they miss. Or host applications. (Or, permit programming!)
Check out this radio’s description. It’s got excess value and pettiness! And a phrase-lock-loop. And “LCD aphellotropic lights of showing screen,facile operation in dark” has got to mean “backlit screen.” (Facile is Spanish for “easy,” no your mom jokes.) Oh, and you can’t forget the Auto-charger rabbet. And it comes with a chargeable battery.
Anyone else confused? (Bonus points: I tried to copy-and-paste a quote, and it carried over the HTML tags, which included <font face=”Wingdings”> at one point….?!)
Mr. T’s post jibed with something that was in the back of my head. I can’t sleep right now, and have sent my friends enough meandering e-mails, so I’ll post here.
For at least the past month, I’ve been in Linux exclusively. I have a 160 GB, 5400 RPM drive with Linux, and a 60 GB, 7200 RPM drive with Windows. (I also have a combination of network storage and external drives for moving/storing data.)
My roommates have been big into Orange Box lately, so I figured I’d give it a try. (It can apparently be made to run under Wine, actually, but I didn’t want to bother.) I swapped out disks, booting into Windows. And it was just one thing wrong after another after that. Admittedly, many of the problems weren’t directly the fault of Windows, but it was truly the worst experience I’ve had in a long time. (Steam was even more badly-behaved than Windows.)
Here are some things that really bug me:
Half-jokingly, I pondered over e-mail, “Why do people ask if Linux is ready for the desktop? The question, I think, is ‘Is Windows ready for the desktop?’ And I’m not sure.” But really, if I have constant headaches, I can only imagine how the people with 75 IE toolbars and lots of spyware and viruses and no idea how computers work must feel. I think my computer is slow? I have bizarre, unexplained errors? I’m confused by technobabble messages that pop up?
Of course, in the interest of fairness, there are two things that I’m liking about Windows:
Oh, see, this is exactly what I hate! As I’m writing this, I can hear my hard drive going. And the disk activity light is on solid. What’s going on? I have no clue! All I have open is Firefox. Some background process is apparently accessing my disk. What is it? I’m not quite sure!
So as anyone who’s seen me in person will surely know, I have a lot of radios. I’ve sold a few lately, but I’ve owned a wide variety. I have the VX-2R, one of the smallest radios ever produced. It’s got an incredible frequency range, too. I have the ASTRO Saber, one of the biggest radios ever made, capable of APCO25 digital voice, trunking, and MDC ID decoding. I’ve owned police scanners and mid-range radios.
Perhaps unsurprisingly, I’ve found that there are big differences between a tiny, $200 radio and a gigantic, $5,000-new ($250 on eBay a decade later) radio. But the huge expensive one doesn’t always win out. If I were designing a radio (which I’d like to!), here’s what it would be like….