Hamming internationally

Historically, one of the major appeals of ham radio was the opportunity to use amateur radio to talk to people in far-off lands.  While the Internet and cheap international long distance has cut into this somewhat, it's still a significant draw of the amateur service, and in fact building international goodwill is an explicit purpose of the amateur radio service (§97.1).  Radio signals have a nasty habit of not respecting national boundaries, and as all of the HF bands have at least long-range if not world-wide propagation at least some of the time, it's very likely that any ham with HF privileges will at some time be involved in a conversation with someone in another country; even someone without HF privileges has a decent chance of it.  The availability of direct, personal international communications via ham radio has been quite controversial historically, and some of the special rules that apply to international communications can be clearly tied to the geopolitical history of the 20th century.

The general rule for international communications for amateur radio operators is that they are allowed.  However, if the national communications authority of either country involved has notified the ITU that it objects to international amateur radio communications, then the communication is prohibited.  The United States does not currently ban any countries, and at the present time there are, in fact, no banned countries.

In addition, all international communications must be "limited to communications incidental to the purposes of the amateur service and to remarks of a personal character" (§97.117).  This is much more restrictive than the rules for domestic amateur radio communications.  The main purpose of these restrictions is to prohibit communications of a political nature, and it is, in fact, a very bad idea in many countries.  Communications of a political nature are permitted in the US (although many of us believe they should be discouraged), but they are, in fact, forbidden across national boundaries and hams would be well advised to avoid them. 

In addition, when operating internationally there are limits on your authority to forward messages on behalf of others (so-called "third party communications").  Third party communications (messages forwarded for people who are not themselves amateur radio operators) are limited to the same terms mentioned above regarding content.  In addition, the general rule for third party communications is that they are prohibited except when specifically authorized, except for emergency and disaster relief communications.  So, while amateurs have the presumptive right to chat with one another, they do not have a presumptive right to pass messages for third parties.  Passing messages for third parties requires that a "third party message agreement" be in effect between the countries involved.  The United States presently has such agreements with about four dozen countries; the current list can be found on the FCC's website.  It should be noted that virtually none of Europe is on this list: third party traffic to European stations is generally prohibited.  This rule also applies to the situation where a nonlicensed person participates in the sending of a message (usually, by allowing someone other than a licensed amateur talk into the microphone).  In other words, if you're in the US talking to a ham in Germany, you may not put your kid on the radio unless your kid is also a licensed ham (the third party rule does not apply if the third party is eligible to be the control operator of the transmitting station).

Another small note: when operating internationally (or domestically, for that matter) it's perfectly acceptable to carry out the conversation in a language other than English.  However, you are required to identify in English, even if the conversation is progressing in some other language.  The internationally-standardized NATO phonetic alphabet, which is encouraged in the amateur service anyway, counts as "English" for the purpose of this rule (which is, for the record, §97.119(b)(2)).

This post has been brought to you by pool questions T1C10, T2B07, T2D05, G1E05, G1E07, G1E08, G1E09, G1E10, and E1F16.  Section references above are to Title 47 of the Code of Federal Regulations, browsable via the GPO Access eCFR service.

Getting along with others: Primary and secondary allocations

There is a general rule of radio operation that says that a station is entitled to operate free of harmful interference from other stations in the same or other services, and at the same time all stations are obliged to operate so that they does not interfere with other stations in the same or other services.  Stations that suffer harmful interference from other stations are generally entitled to relief from such interference; that is, the national administration responsible for supervising the interfering station is generally obliged, under law or treaty, to take steps to cure the interference, if the interfering station doesn't do so first.  However, this rule is a very general one, and (like most rules) is subject to some exceptions.  This post is about one of those exceptions: the system of primary and secondary allocations.

I've mentioned the ITU a few times now, and that one of their major responsibilities is frequency management.  One of the things that the ITU, and also national regulators such as the FCC, do in furtherance of this is sometimes allocate a band to more than one use.  When they do so, they will typically designate one of those uses as "primary" and the other(s) as "secondary".  When a band has been designated with both a primary allocation and a secondary allocation (either by the ITU or by the FCC), this modifies the general rule regarding cross-service interference.  Specifically, a station in a service which has a secondary allocation in a particular band has no right of protection against interference, harmful or not, from stations in a service which has a primary allocation in that band.  Such stations, more succinctly referred to as "secondary stations" in §2.105(c)(2), must at all times yield to primary stations and take steps to avoid interference.

Many of the bands allocated to amateurs are also allocated to other services.  For example, the entire 70cm UHF band (420-450 MHz, in the United States) is a secondary allocation for amateurs; the primary allocation is federal and the principal user is the military, who mainly uses this band for various radar systems, most notably the PAVE PAWS early warning system deployed at Beale AFB and at Cape Cod AFS (which leads to limitations on the use of the 70cm band for hams in proximity to either of these sites).  Another band for which the amateur service is a secondary allocation is the 60 meter HF band.  The 60 meter band is channelized and is the only band on which an amateur may not transmit Morse code.  It is shared with the federal government (the primary user) and amateurs must immediately cease operation if interference is caused with a federal station.

The situation with the 30 meter band is even stranger.  While 30 meters is primarily allocated to hams by the FCC, that allocation is only valid within the United States and its outlying insular regions.  Outside that area, the 10100–10150 kHz band is allocated primary to the fixed service, and a footnote (footnote US247) to the Table of Frequency Allocations (§2.106) states that "[t]he band 10100–10150 kHz is allocated to the fixed service on a primary basis outside the United States and its insular areas. Transmissions from stations in the amateur service shall not cause harmful interference to this fixed service use and stations in the amateur service shall make all necessary adjustments (including termination of transmission) if harmful interference is caused."  Because 30 meters has worldwide propagation (and in fact is one of the most interesting bands there is in terms of propagation), interference is pretty easy here, which is probably part of why hams in the US are limited to 200 watts in this band (instead of the more usual 1500), and why this band is the only amateur band with no voice privileges anywhere within the band.  (I've yet to find out the specific, historical reason why this band has this rather unusual noninterference restriction and to what purpose the other fixed stations in this band used it or if they're still there.  If anyone knows, please do let me know.)

This post has been brought to you by pool questions T1C09, G1A14, and G1A15.  Section references above are to Title 47 of the Code of Federal Regulations, browsable via the GPO Access eCFR service.

How long is your band?

When talking about frequency, and especially about "bands" (divisions of spectrum made for the purpose of allocation), it's very common to see frequencies specified in units of length (meters and centimeters being most common) instead of in units of frequency (kilohertz, megahertz, or gigahertz, or, more archaically, kilocycles or megacycles).  When a length unit is used, it specifies the wavelength involved.  The wavelength of a light wave is, of course, directly related to its frequency: the wavelength is the distance the wave travels (at the fixed speed of light) over the period of one oscillation, and so wavelength is just speed divided by frequency (and frequency is speed divided by wavelength).

Fortunately, the math for this is pretty simple, especially in the metric system (which even us backward Americans use when doing ham radio, thankfully).  By pure serendipity, the speed of light (in a vacuum) is approximately 299,792,458 meters per second; this is close enough to 300,000,000 meters per second that for most purposes the latter value can be used.  So to convert a wavelength in meters to a frequency in megahertz (or vice versa), one must merely divide 300 by the wavelength (or frequency).  Hams routinely refer to all the amateur bands below 200 MHz by their wavelength instead of their frequency, and it's quite common to hear the higher frequency bands by wavelength as well, so it's important to be able to do this translation on the fly (at least until you memorize the more common ones).  Fortunately, dividing into 300 isn't that hard.

So when a ham talks about the "160 meter band", they're not talking about a really long parade; instead, they're talking about a band whose wavelength is approximately 160 meters, which corresponds to a frequency of about 1875 kHz.  The 160 meter band is actually 1800 to 2000 kHz, so this is pretty close.  Other examples (more pertinent to the student preparing for the Technician exam) include the 6 meter band (50 to 54 MHz), the 2 meter band (144 to 148 MHz), the 1.25 meter band (222 to 225 MHz), the 70 centimeter band (420 to 450 MHz), and the 23 centimeter band (1240 to 1300 MHz).  Please do note also that these band definitions apply only in ITU Region 2 (and obviously only in the United States or other places where the FCC regulates amateur radio), and that other restrictions based on location may also apply (especially with respect to the 70 centimeter band, which has a lot of interesting restrictions on it).

Of the questions on the Technician exam related to this, two (T1C04 and T1C06) present an additional challenge that cannot be resolved simply by dividing into 300, as there are incorrect answers that are "close enough" that you can't eliminate them based solely on approximate wavelength.  Therefore, it's very important that you commit to memory the limits of the 6 meter, 2 meter, and 70 centimeter bands given above, not only for the purpose of passing the exam but also for the purpose of responsible operation.

This post has been brought to you by pool questions T1C04, T1C05, T1C06, T1C07, and T1C08.

Mayday, mayday, mayday: Emergency operations

Quite a lot of people get into amateur radio for the purpose of emergency communications.  There are two meanings to that phrase, too, and it's important to keep them straight.  The first, "emergency communications", is the provision of communication assistance during an "emergency"; that is, responding to a station in distress and, based on the ensuing communication, providing assistance directly or dispatching others to provide assistance.  The second is more strictly a "communications emergency", which is when an emergency situation cause (or is likely to cause) a failure or breakdown of ordinary communications systems.  Amateur radio operators have specific powers and duties in both of these situations.  Providing emergency communication is one of the declared purposes of the amateur radio service, so hams should have some understanding of these powers and responsibilities.

Amateurs are, generally speaking, not permitted to communicate with stations in other services using their amateur radio station.  This includes the licensed-by-rule Family Radio, General Mobile Radio, Citizen's Band, or Multi-Use Radio services.  Even though all of these services are available to anyone (other than a representative of a foreign country) who possesses the appropriate equipment, hams are not exempted from the requirements in these services to use type-accepted equipment and hams who wish to operate in these services must ordinarily meet these same equipment limitations and requirements as any non-ham would.  Nor may a ham use his or her equipment to communicate with public safety entities.  There are, of course, exceptions to this general rule, almost entirely for emergency situations. 

There are three major exceptions for "emergency" situations:  First, an amateur may use any means of radiocommunication at his or her disposal in order to provide essential communications needs during an emergency which immediately threatens human life or property, when other forms of communication are unavailable or disrupted.  Second, an amateur station which is actually in distress ("distress" also being a term of art which in this case means "in immediate threat of loss of life or serious permanent injury") may use any means at its disposal to attract attention and obtain assistance.  Third, an amateur station who is aware of a station in distress may respond to that station in distress or make any other communications necessary to obtain assistance for that station in distress, even if that would involve transmitting to stations outside the amateur service or using frequencies not authorized to the amateur.

These exceptions are to be construed very narrowly, in practice.  The communications must be "essential", the threat to life or property must be "immediate", and other forms of communication must be "unavailable".  Don't use this one lightly; if you have a choice between running next door to use their phone to call 911 or transmitting on the local fire department's general frequency, please go next door and call 911.  This is intended as an absolute last resort "when all else fails", not an option to used when other options are merely inconvenient.  Similarly, if you are monitoring, say, the marine HF bands and you hear a Mayday call, do not immediately respond; you might interfere with other ships or the Coast Guard responding.  Only if you do not hear a response, or if the calling station repeats the call (instead of responding to a response to their Mayday call) should you "unlock" your gear and respond to the calling station, or relay the call.

In addition, the FCC may declare a "communications emergency" when a disaster causes the loss of normal communications in an area.  During such a declaration, amateurs must refrain from using any frequencies designated in the disaster declaration unless they are actively involved in providing assistance.  Such declarations are common during major disasters, such as hurricanes and earthquakes, which tend to disrupt normal communications.   The FCC may also authorize amateurs involved in providing assistance to use frequencies other than those which are normally available to amateurs, or to communicate with stations not in the amateur service, during a communications emergency; amateurs are required to comply with the directions of the FCC and its Field Engineers in such situations.

Outside of an FCC declaration of an emergency, no frequencies are reserved for emergency communication; there is no amateur equivalent of CB channel 9 or marine channel 16.  In general, the best frequencies to use for declaring an emergency in the amateur bands would be the various national calling frequencies, because there's a better chance that someone will be listening on one of these.  However, emergency traffic always takes priority over non-emergency traffic, on all frequencies and at all times.

It should go without saying that if you hear a station calling with an emergency (for which the most proper method to call "Mayday" three times, followed by identification) any non-emergency communications on the same frequency must immediately suspend until the emergency is resolved.  At the very least, do not interfere with emergency communications, and to the extent that you are able, you should assist the station in distress.  (But avoid creating confusion; listen closely and think before you transmit.)  You should always assume that a declaration of emergency is real; if it's not, the station calling the emergency is the one on the hook for making a false distress call.  In the United States, making a false distress call is a federal felony; offenders will almost certainly lose their FCC licenses, and will face stiff fines (in one recent instance, $45,000) and even the possibility of prison time, so don't do that.

This post has been brought to you by pool questions T1C03, T8A01, T8A02, T8A03, T8A04, T8A06, T8A08, T8A09, T8A10, T8A11, T8A12, T8B08, T8B11, and T8C01.

What's in a call sign, anyway?

Most people have some familiarity with call signs, if nothing else from broadcast radio stations, which in the US tend to be four letters starting with either K or W.  The more knowledgeable will know that in the broadcast services, K stations are west of the Mississippi and W stations east of it (with some grandfathered exceptions).  Those near the borders may know that Canadian stations start with a C, and Mexican stations with an X.  But, unless you're a shortwave listener or a ham, you probably don't know why the letters used are K and W, or what other letters might be used for, if anything.

The ITU, which I talked about in my last post, is the entity that makes the rules that everyone has to follow for call signs.  Each member country is assigned one or more one or two character prefixes (or, in two cases, three character), and all call issued by that country have to start with one of those prefixes.  There are nine one-character prefixes: B, F, G, I, K, M, N, R, and W; the United States, being a charter member of the ITU and the largest at the time that it was decided to regularize call signs, got three of them; (N, K, and W); the UK gets two (G and M), and the other four go to China (B), France (F),  Italy (I), and Russia (R).  Everyone else has to use at least two characters for national identification; Canada, for example, is allocated CF through CK, and Mexico is allocated XA through XI.  (Both countries have other allocations.)  Some countries even have prefixes that start with digits instead of letters.

So why N, K, and W for the US?  France, Italy, and Russia got their initials, after all.  Well, during the early years the US military used A call signs for Army stations and N call signs for Navy stations.  W (. - -) and K (- . -) are what you get when you add a dah to the Morse code for A (. -) and N (- .), and so commercial stations adopted those letters.  The United States has since given up part of A for the use of other nations, and now only has AA through AL (in addition to all of W, K, and N).

In addition to allocating prefixes to the many member nations, the ITU also sets standards for the parts of the callsign after the prefix, at least in certain services.  For amateur radio stations, the ITU mandates a one or two character national prefix, then a digit, and then up to four additional characters, the last of which must be a letter.  For the United States, which has three one-character prefixes, that means a callsign can be as short as three characters or (in theory) as long as 7.  The FCC, however, does not issue four-character suffixes yet, and reserves the so-called "one-over-one" callsigns (one letter, one digit, and one more letter) as "special event stations" (which are issued for short-term use by any ham who requests and obtains one from the NCVEC, who administers that program, and never permanently), so all FCC-issued amateur call signs are four to six characters long.  Not all combinations within this space are used, either; the FCC excludes for the moment all "two-over-three" (two letters, one digit, and three letters) call signs beginning with A and N from the amateur service, and excludes certain others combinations for a variety of other reasons.  Also, while the ITU regs would allow for the issuance of a call sign containing more than one digit, the FCC does not do this; US amateur call signs always contain exactly one digit.  And that digit is not entirely without meaning.

For the purpose of the amateur radio service, the FCC divides the country into 13 regions.  The first 10 regions, numbered 1 through 9, and 0, are groupings within the "lower 48" (see map to right).  Regions 11 through 13 are Alaska; Puerto Rico and other Caribbean islands; and Hawaii and other Pacific islands.  The FCC issues call signs based on what region the amateur's mailing address is in, and within each region based also on the amateur class of license, using what is called the sequential call sign system.  For those in regions 1 through 10, the digit in the call sign corresponds to the region number; for regions 11, 12, and 13 the digit used also depends on location (typically, which island you're on).  Every amateur gets a sequentially-issued call sign initially; after that a ham's call sign will only change (barring extraordinary events) if the amateur, applies for a vanity call sign or requests a new sequentially-issued call sign.  Also, once the FCC has issued a call sign, it will never issue it again via the sequential system; the only way for a call sign that has been abandoned to be used again is via the vanity call sign system. 

In addition to dividing the country into 13 regions, the call signs available in each region are further divided into four groups, A through D.  Calls in Group A are reserved only to Extras; those in Group B are available to Extras and Advanceds; those in Group C to everyone except Novices; and those in Group D are available to any amateurs.  Because of this, you can tell from a call sign what the minimum license class someone has: someone with a two-over-one or a one-over-two is necessarily an Extra.  But you cannot assume that someone with a two-over-three is a Novice (and in fact that's almost certainly not the case), for three reasons.  First, a ham who upgrades does not automatically get a new call (anymore; that used to be different), and so could have a higher license class than his or her call sign group indicates.  Second, a ham may request any call sign which is permitted to his or her license class through the vanity program.  The third, and perhaps most common, for call signs that don't fully reflect the licensee's operating class is that Group C is exhausted in almost all regions, which means new General and Technician licensees (in the lower 48, at least) now get two-over-three "Novice" calls (as do initial club licenses, which are applied for through Club Station Call Sign Administrators, instead of the usual VE process). 

This post has been brought to you by pool questions T1B03, T1B04, T1B05, T1B06, T1B08, T1B09, and T1B10.