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Ham radio 101, please
January 28, 2011 12:03 PM   Subscribe

Please tell me about ham radio. This thread on the blue about the protests in Egypt contains a number of comments about ham radio and its utility in situations where the Internet is unavailable. Assume I know nothing about equipment or the process of becoming an operator (because this is true).

(I put this in the sports/hobbies category because that's how I've always thought of ham and shortwave radio enthusiasts, but I know there's more to it than that.)
posted by catlet to Sports, Hobbies, & Recreation (35 answers total) 108 users marked this as a favorite
 
You need to read the FCC page on amateur radio.
posted by valkyryn at 12:15 PM on January 28, 2011 [7 favorites]


My husband is a ham and enjoys the hobby greatly. Ham enthusiasts are a tight group, so you could probably find someone to be your elmer (learning mentor) offline. The hams are so full of original geek that you'll learn about more than just radio. That's just my XYL bit.
posted by Calzephyr at 12:28 PM on January 28, 2011


If ham radio is useful in Egypt during the current conflict, it is only useful because few people have it, and it isn't on the government's list of media to crack down on.

Ham radio is a specific set of frequencies set aside for amateur radio communication. You can transmit plain voice / audio or you can encode and transmit data at low bitrates.

The problem is that radio broadcasting stations are easy to detect by virtue of the fact that they are broadcasting radio signals. A hostile government can send the army over to cut the power or just jam the signal.
posted by b1tr0t at 12:28 PM on January 28, 2011


In the US you need a license to transmit on the ham bands. There are three license levels, each one gives you more privileges than the one before. Two good study guides for the Technician (1st) and General (2nd) exams can be found here. The Extra (3rd) class exam is really the only one that you can't pass by spending a day memorizing things.

With the technician license you can transmit mostly on the VHF (very high frequency ex 144 Mhz) and higher bands. Signals on these bands are more limited to line of sight (ex 50 miles) and less likely to travel long distances by bouncing around in the atmosphere (ex 10,000 miles). A general or extra class license will allow you to transmit on the HF (high frequency (30 Mhz) and lower bands, which in theory allow for longer distance communication with less effort. To transmit of course you will need a transmitter and to receive you will need a receiver. When they are built together you have a transceiver. Of course you will also need at least one antenna. Most hams buy their equipment off the shelf but some still build at home, either from kits, plans or scratch. Most home-brewed equipment is QRP - low power.

You can communicate by using any number of modes - FM voice, AM voice, SSB voice (basicaly 1/2 an AM signal) or you can encode your data in morse code or a digital mode (similar to how an analog phone modem sounds). Most of the innovation these days in ham radio is around new digital formats and software defined radios.

Many hams practice field day events where they simulate responding to a disaster, operating from generator power or from a remote location. If you are interested in emergency communication systems you may want to see if any are scheduled near your home. The ARRL can be a good place to start, but be warned that although they are the main advocacy group for ham radio in the US they are fairly stodgy.

If you want to listen to the ham radio bands without spending any money WebSDR puts several receivers on the Internet and allows you to tune around as much as you want listening in to other conversations (which is not creepy in ham land).
posted by ChrisHartley at 12:32 PM on January 28, 2011 [13 favorites]


If you're actually in the Atlanta area, your local ARRL branch is at http://www.arrl-ga.org/. Some useful sites in no particular order: The ham radio culture has a whole lot of really old conservative white guys in it. There's starting to be a bit more crossover with more modern/younger hacker crowd, but it's not nearly as extensive as you might expect. The radio nerd and computer nerd cultures had a split somewhere along the line, and most young nerds got into computers and not radios. The folks at makezine have been pimping ham radio a bit, particularly with Diana Eng as a contributor. Also, amusingly, some of the steampunk folks are getting hip to telegraph keys and morse code and using them in projects. (morse code: it's not just a plot point in "Cryptonomicon" any more!)
posted by rmd1023 at 12:34 PM on January 28, 2011 [5 favorites]


That is a pretty broad question. There are the specifics and then the...harder to describe parts of ham radio operation.

The licensing requirements are different in every country. Are you in the US? The FCC runs licensing in America, and the process and resulting categories have gotten much simpler over the years. Right now, there's just Technician (multiple choice exam), General (Technician + another multiple choice exam), and something like Advanced Extra (all of the above plus another theory exam). The different classes give you different privileges and access to different bands - certain frequencies are only available to Amateur Extras, etc. There are a lot of books available to help you study, classes, and even full tests online. When I looked into it years ago, you were required to pass a Morse code proficiency exam and got access at first only to Morse-code-only bands, but that requirement is now gone.

A good way to start is to get involved in a local radio club. Those old guys will talk for days if you show the tiniest glimmer of interest, and there will always be somebody who will kind of take you under his wing. When you're ready to take the test, you can find one through your contacts or through ARRL.

You could also pick up a police scanner and just listen in (no license required). There are lists online of popular, well-traveled frequencies. It will give you a feel for the etiquette.

Basic equipment to get your home station going would be a transciever (transmitter/receiver) and an antenna. It seems to me that it would be easiest to buy the first pieces new at once, in a bundle, cables and all. Don't break the bank at first; you will inevitably develop obsessions over things as you follow your own particular rabbit hole of ham equipment interest. Your local guys would be a good source for specifcs, or my dad likes this review site a lot. You must have a license to get talking.

If you fall in love with it, there are hamfests to go to and a crazy online galaxy of ham-related content and interaction, Kelley Blue Book-like listings of equipment values to peruse, field days for emergency response practice, all kinds of stuff. You might find that you're one of the guys who loves the equipment, starts buying vintage pieces or rolling your own. You might find that you meet a lot of people and make a whole bunch of new friends. Or maybe you will find yourself the receiver of information out of a corner of the world where things have gone pear-shaped. People are very particular about what they like about ham radio. There are quite a lot of lonely weirdos. There are a lot of old guys with fantastic stories. Youth participation is declining; sadly; people keep trying to do outreach stuff to keep it alive. It can become a very (sometimes too) absorbing hobby.

Disclaimer: I never did get my novice license, but my dad is a passionate ham, one of those built-his-first-radio-out-of-a-spam-can-and-army-base-detritus-at-age-8 guys. I went to a lot of hamfests with him as a kid, hung out with his slightly off Vietnam vet ham friends. Most of his friends are people he met at one point over the radio. He has books full of old-school call sign cards he's received from all over the world and a basement full of beautiful vintage equipment in various states of repair, from pristine stuff he clucks over lovingly to battered military issue stuff he's cannibalized or opened up "just to see". He has insanely complex computer programs to control his (many) radios and Facebook open all the time to chat with his ham friends. His HOA at his new house yelled at him for erecting giant antennas in the woods behind his house. The soundtrack to my childhood Sundays is the particular squeal of the radio as he turned the dial (and my mom yelling at him to leave it alone, you're only home one day a week, we're right here, talk to us!). Most of the technical knowledge is pretty impenetrable to me, but when I go to visit and hang out with him in the basement I get it - the crackle and buzz and the voice coming at you, traveling on a wave from somewhere else far, far away.
posted by peachfuzz at 12:41 PM on January 28, 2011 [11 favorites]


Ham radio is a broad hobby. People get involved for a variety of reasons. The following are some activities that different ham radio operators might enjoy. And there are many other things I have certainly left out.

To become an amateur radio operator in the U.S. you must pass at least one multiple-choice examination which is administered by volunteers under the oversight of the FCC. There are three classes of licenses in the U.S.: Some other countries have similar license classes; others base their classes on different criteria such as transmit power rather than frequency access.

Amateur radio operators are allowed to build and operate their own experimental equipment, providing it complies with certain transmission characteristics (power emission, primarily). However, most amateurs purchase radios from commercial providers such as Icom, Yaesu, and Kenwood.

Amateurs also build their own antennas, though commercial antennas are also available.

With the right radio and the right antenna, it is possible to communicate with other amateurs around the world, given the right propagation characteristics.

In addition to voice communication (FM, AM, SSB, etc.) hams also use various digital modes. These are typically low-bandwidth (on the order of bytes per second) and require substantial error correction, especially over HF.

FCC regulations require U.S. hams to abide by certain regulations when it comes to the content of transmissions, whether voice or otherwise. Hams cannot transmit music, and are not allowed to use amateur frequencies for commercial purposes. Additionally, messages are only intended to be passed directly between hams. Messages passed on behalf of a non-ham third party (known as "third party traffic") are only allowed between certain countries where a thirty-party traffic agreement exists.
posted by Nothlit at 12:44 PM on January 28, 2011 [1 favorite]


Also, I should mention that, by law, ham radio transmissions cannot be encrypted. Voice transmissions cannot be scrambled, and any digital transmissions must use publicly available plaintext standards. Hams are also required to transmit their callsign at the end of every transmission, or at least once every 10 minutes during an ongoing communication. Therefore it's not intended to be used as a clandestine means of communication.
posted by Nothlit at 12:50 PM on January 28, 2011


The ARRL is probably the largest ham organization. eham.net and qsl.net are some relevant websites, if you want to take a look.

Ham radio really consists of a number of sub-hobbies. A lot of its utility/interest has waned since similar technology has made it into the consumer world— being able to communicate while out and about is something you can do with a cell phone now, and talking to people from around the world is something you do on the internet now. But a lot of the sub-hobbies are still active: And of course there are still places that cell phones don't reach, so it's not unusual for hikers, hunters, etc. to have a radio to keep in touch.
posted by hattifattener at 12:51 PM on January 28, 2011 [1 favorite]


When I looked into it years ago, you were required to pass a Morse code proficiency exam and got access at first only to Morse-code-only bands, but that requirement is now gone.
In fact even the Extra class no longer has any Morse requirement, a fact which I find kind of disappointing. For a little while I was planning on upgrading my license purely to give myself a motivation to learn Morse.
posted by hattifattener at 12:55 PM on January 28, 2011


A bit off topic from the original question but if you are interested in learning morse code LCWO.net is by far the best resource I've found, especially the MorseMachine tool. Morse code is really old but when you only have an old CFL lightbulb and you need to build a transmitter to get the word out.... Hard to beat.
posted by ChrisHartley at 1:06 PM on January 28, 2011 [1 favorite]


Some hams like to make the most out of the least, using minimal power (QRP) or using solar power (and batteries) or simple antennas. Which is what makes ham radio so valuable in a situation like Egypt where the government has control over so much of the normal communications infrastructure. A fairly simple setup can still get your signal out to the world.

But it's not without risk, as mentioned above. There's no encryption capability, even for digital transmissions, and your signal can be used to trace your station's location.
posted by tommasz at 1:09 PM on January 28, 2011 [1 favorite]


You can listen to ham radio in your area here
posted by jara1953 at 2:23 PM on January 28, 2011


Lots of good answers above. The beauty of ham radio is that an operator can talk across town or for long distances (or often both) using a pretty simple setup, making this invaluable for disaster or other situations, when commercial power and communications are disrupted.

S/he can do this off the power grid, using a generator, a bank of batteries that are charged and maintained for this purpose, or have this setup in a vehicle, hooked up to any car battery. A ham can pack up his/her equipment in a backpack, go almost anywhere, and transmit across town or halfway across the world. They can go set up and render assistance very quickly.

There are other hams who will scan the frequencies and listen for anyone who needs help or is trying to convey information, and are ready to offer any assistance.

Before I got into the hobby, I thought it was magic that hams could communicate news of loved ones out of an earthquake- or hurricane-stricken area. That feeling has not changed since I got my license.

Aside from the initial outlay for equipment, none of this is dependent on any service provider, unless you count the atmosphere as such.

Examples of cool things hams have done: Bonus cool thing: Do a google search on "ITU phonetic alphabet". Hams use this, because it's such an efficient way to spell out things. Have you ever awkwardly spelled out your name to somebody? "Ralph. R as in, um, radar. A as in, er, apple, L as in,... lampshade. P as in paddle. H as in Henry." A ham, using the phonetic alphabet, will rattle off "Ralph, I spell: Romeo Alpha, Lima, Papa, Hotel. Ralph" and be done with it without having to think about it, using example words that are easily understood in many languages. How cool is that? There's a software company that trains its tech support personnel in the use of the ITU phonetic alphabet. It's great for making those pesky, long, alphanumeric serial numbers more easily understood.

And to think, people who think antennas are unsightly go to all the trouble to enact homeowners' regulations to prevent people from putting them up. Huh. Antennas are actually quite beautiful, for the above-listed reasons, I think. /soapbox
posted by SillyShepherd at 2:50 PM on January 28, 2011 [1 favorite]


Oh, some hams will have much fun playing with signals. One will hide a low-power transmitter somewhere, and a bunch of other hams will use direction-sensitive antennas to find the transmitter. They call this fox hunting. It's also good for locating interference (jammers, a transmitter that might be malfunctioning, or something on a utility pole that is malfunctioning).
posted by SillyShepherd at 2:53 PM on January 28, 2011


There is a large cross-over between hams, volunteer firefighters and auxiliary police.
posted by gjc at 3:45 PM on January 28, 2011


LOL, I was just looking this up myself today. My dad used to have an Expert class license when I was a kid and I would sit on his lap and talk with people all over the world. I was his secret weapon in contests because the pitch of my little-girl voice cut through the buzz of other hams trying to work a contact from an obscure country, and everyone always wanted to talk to the "YL" (young lady). I started studying for my own license but never finished.

Anyhow, if you'd like some books, here is what is currently sitting in my Amazon shopping cart while I decide whether I really want to take it up again:
Ham Radio for Dummies
Technician Class 2010-2014
The ARRL Handbook for Radio Communications 2011
The ARRL Operating Manual For Radio Amateurs
Basic Radio: Understanding the Key Building Blocks
Understanding Basic Electronics
posted by Jacqueline at 3:49 PM on January 28, 2011 [1 favorite]


Thanks for all the great info so far! The start-up cost is out of my range right now, but I'm increasingly fascinated - particularly with the disaster/emergency applications.
posted by catlet at 4:35 PM on January 28, 2011


I don't know your budget but you can get started for about $100. I have a Puxing 777 2M handheld that I got for about $75. Out of the box I can talk to other local hams via repeater and for $15 in parts I built a J-Pole antenna that allows me to reach about 50 miles out with just 5 watts. My next project is going to be a $25 2M Yagi antenna for moon bounce and satellite communication.

The proliferation of cellphones has really supplanted ham radio in many disaster situations (everyone has their own personal pocket radio! that connects to the POTS!) but a 2M handitalki (HT - I don't know how any says handitalki with a straight face) could be a life saver next time a tornado takes your town apart/you need to coordinate a street protest against an oppressive government.

If you hack apart a cell phone hands-free cable you can hook the Puxing to a computer and start playing with digital modes like APRS - sort of similar to SMS but typically used for automatic position reporting.

If you already have electronics/soldering knowledge you could look at KB9YIG's softrock line kits - $20 to $74 and they offer performance in line with systems costing $200-$750. I'm still working on my transceiver kit from last summer so the cost per hour of building entertainment is also extremely low.
posted by ChrisHartley at 5:02 PM on January 28, 2011 [1 favorite]


Found this Wired how-to wiki via a link on the blue tonight: Become a Ham Radio Operator.
posted by MonkeyToes at 5:05 PM on January 28, 2011


Offtopic - if you have experience with shortwave reception in the Pacific Northwest, please MeMail me, I've got a few questions.
posted by b1tr0t at 9:17 AM on January 29, 2011


The Ethos:
The amateur license is like the $5 hurdle here at MetaFilter: just high enough to not be a drive-by formality but easily achievable without going to university for electrical engineering.

The fact that the demographics of amateur radio are tilted towards seniors might be responsible for the previous commenter's experience of prejudice, more than the radio hobby. In my experience amateur radio people have been community-minded and inclusive.

The Gear:
A power supply was the first thing I bought. A good sized solid state 50 amp Astron would cost about $250 new, but could power an average VHF, HF and UHF radio simultaneously, while a cheaper 'switching' power supply could be bought for about half that amount. (Solid state are much lighter, so if you plan on moving it around, this might trump the other advantages of going solid state.

If you're still interested, consider going to the next meeting of your local amateur radio club. Where I am for example, the club is planning to give away to the next person to get their license a spare used radio that was donated.
posted by HLD at 12:31 PM on January 29, 2011


As a student at MIT interested in developing technologies appropriate for protests under repressive regimes, I went to my local ham club to ask people about what sort of scenarios might be possible (I was imagining building cheap portable devices for clandestine digital coms).

I was disappointed that everyone in the club was interested in following the letter of the law, even in circumstances where the law is oppressive and unjust. Which means no news, no politics, no encrypted transmissions, no anonymous transmissions. The FCC only allows ham radio to exist because it's utterly toothless; and the community seems to have absorbed that line, and actively self-enforces it.

It's disappointing, because there could be so much potential there.
posted by yourcelf at 3:08 PM on January 29, 2011 [2 favorites]


A related question after failed searching: I want to give Ham a try but I live on the 12th floor so antenna space is limited. Does antenna size correlate with the reach of transmission and reception?
posted by vapidave at 4:38 PM on January 29, 2011


Yourcelf, there's nothing wrong with talking news or politics, although a professional journalist should not use the amateur service for commercial newsgathering.

You seem surprised that hams will defend their spectrum against commercial use. Why is that? Metafilter users do the same thing, and for the same reasons. You've got to fight it, otherwise commercial user will take over.


It's disappointing, because there could be so much potential there.

Yes, a lot of potential. The amateur radio service is the one and only non-commercial, non-governmental radio service we have. The only damn one.

If you want to play around with encrypted transmissions, why not do it on the unlicensed ISM bands? If you feel compelled to do something illegal, at least have the decency to crap on Clear Channel or some other non-critical commercial user, rather than a bunch of hobbyists.
posted by ryanrs at 4:48 PM on January 29, 2011 [4 favorites]


vapidave: yes, but you can do a lot with an antenna that fits indoors and which you take down when you're not using it. Just don't expect to work Punta Arenas with it.
posted by hattifattener at 4:52 PM on January 29, 2011 [1 favorite]


Does antenna size correlate with the reach of transmission and reception?

Yeah, sort of. The two main rules are:
1) Height is very important. The 12th floor is a good place for an antenna.
2) Antennas for low frequency bands are larger. VHF and higher are usually less than several feet long.

What band are you thinking of? Or more generally, how far? Got a balcony?

Don't forget you can chat on VHF via the local mountaintop repeater with nothing more than a handheld walkie-talkie.
posted by ryanrs at 5:01 PM on January 29, 2011


What band are you thinking of? Or more generally, how far? Got a balcony?

The furthest I can get, that's the part that initially appeals to me.
We have a balcony on the east and an openable window to the north that I could place an antenna outside of temporarily. This is in Winnipeg so line-of-sight is only limited by the curvature of the earth.
posted by vapidave at 5:41 PM on January 29, 2011


I don't mean to rile you up, ryanrs -- but the OP asks for use of Ham to support Egyptian protests. That's pretty risky without some means of anonymity.

If you want to play around with encrypted transmissions, why not do it on the unlicensed ISM bands? If you feel compelled to do something illegal, at least have the decency to crap on Clear Channel or some other non-critical commercial user, rather than a bunch of hobbyists.

When Mubarak is the law, a lot of folks find that it's worth doing something illegal. Reliable communications in a time of political, and not just natural disaster, requires skill and development. ISM and other bands are great too; but that's not what Hams do; it's different equipment and a different skill set.
posted by yourcelf at 5:56 PM on January 29, 2011


Oh, I'm not riled, I'm just letting you know where the hams are coming from. They're very protective of their spectrum.

Even in times of revolution though, I think you'll still want to stay away from them. It pains me to say it, but if anyone is going to track you down and tip off the authorities, it's the hams. They have the expertise, they have the equipment, and when the revolution comes, every last one of them will be on the air. And as you discovered, they're not a very revolutionary bunch.

But aside from the hams, who else do you think is going to be monitoring for clandestine transmitters? Certainly not the knuckle-draggers carrying the batons.

---
I fear that I'm dragging the conversation off-topic. Send me a memail if you'd like to chat some more, yourcelf. About ten years ago I charged a line of riot police while wielding a homebrew illegal transmitter. So I feel I have a fair amount of technical and practical experience in these matters. [not joking]
posted by ryanrs at 8:05 PM on January 29, 2011 [1 favorite]


Ham radio has been popular on and off, so you might be able to pick up equipment free on your local freecycle.org or cheap/free on Craigslist.
posted by theora55 at 4:39 AM on January 30, 2011


Here is a good article on stealth amateur radio including information on indoor antennas. You can have a lot of fun with ham radio even if you can't put a 40' tower outside.
posted by ChrisHartley at 6:50 AM on January 30, 2011 [4 favorites]


People interested in this thread should check out Devonian's excellent post on the blue, which addresses some of the issues of politics raised here.

Thanks, everyone, for your contributions.
posted by catlet at 7:40 AM on January 31, 2011


Very late add, but I've always been interested in radio receivers (built a few) and this year I just bought a NEW old-stock Chinese military receiver & transmitter (radio nerd heaven to unpack a brand-new military tube radio that was packed like 38 years ago) and I intend to get my licence, and learn Morse.

If you know or are willing to learn electronics, you can get on the air with salvaged & repaired, or home-grown equipment for quite cheap. This is the route I'm going, just because i enjoy the research/building part. Even without the electronic bg, you can get on the air for less than a grand, which isn't alot considering many will lay out more than that for a bicycle they ride a few times a year.
posted by Artful Codger at 7:13 AM on February 14, 2011 [1 favorite]


Ham Radio communications aren't easily blocked, so I doubt any govt can do that technology wise. Not only are the bands and frequency allotment vast, hams operate in several modes from AM, FM, TV, SSB (single sideband), CW (morse code), RTTY/Data! Not only that, but many ham radios operate in the shortwave band which means the signals shoot up in the sky and are refracted (bounce back) to earth, which means their signals can carry across the globe! On top of that, ham radio operators can bounce signals off of the moon and/or even use "satelites" in orbit to communicate! I think it's virtually impossible to stop these communications due to the vast amount of diversity the hobby offers.
posted by radioguy at 2:17 PM on October 2, 2011


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