Let's get basic for a few paragraphs... and if you're an old-timer, you might want to read through this section just to see if we got it right.
First, what exactly is a "repeater"? And why do we use them?
Without repeaters, the communication range between Amateur VHF-FM mobile and handheld radios at ground level is limited -- five to fifteen miles for mobiles, and just a couple of miles for handhelds. The distance you can communicate is usually referred to as "line-of-sight" -- you can talk about as far as you can see (if you cut down the trees).
To extend our range, we use repeaters. A repeater is a specially designed receiver/transmitter combination. When you operate through a repeater, its receiver picks up your signal on the inputfrequency, and the transmitter re-transmits -- or "repeats" -- you on the outputfrequency. For example, one of the RARS repeaters hears you as you transmit on 146.04 MHz, and repeats you onto 146.64 MHz. You'll hear this repeater referred to as Six-Four.
Repeater antennas are located on tall towers, buildings, or mountains, giving them much greater range than radios with antennas near the ground. And when you're in range of a repeater, you can talk to everyone else in range of that repeater.
RARS' 146.64 repeater is located in west Raleigh, near the beltline and Hillsboro St. Its antenna is on the side of a tower that puts it about 350 feet above average terrain. A mobile station running 50 watts can reliably communicate through the repeater out to about 35 miles. So if you were 35 miles north of the repeater, you could talk to someone 35 miles south of the repeater. That's 70 miles between you -- a whole lot better than the 10 or so miles you could cover without the repeater!
Repeaters can have many features
beyond just extending the range of mobile or handheld radios. One
especially useful feature is called Autopatch. A telephone line
and special control equipment at the repeater allow you to make local
phone calls from your radio. Now, this is not exactly a replacement for
a cell phone. You can't use Amateur Radio for your business,
including autopatch. You can't receive calls, you can make only local
calls, and your conversation is not private! Everybody
else listening to the repeater hears your call. Still, autopatch is
handy, within its limitations.
There are literally thousands of repeaters across the US (and the world). Each one can have it's own peculiarities and unique operating procedures, but there are some basics that apply to almost all of them. Really complete instructions would fill a book, bore you to tears, and start some fights about what's correct and what's not (operating procedure is a matter of strong opinion in Ham Radio!). We'll risk all of that now, but try not to fill a book.
PLAIN OLD TALKING. Mostly, you're here to get on the air and chat, right? OK, first you set your radio for the repeater you want to use. Don't know how to find a local repeater frequency? The RARS web site has a list of the Triangle area 2-meter repeaters. Check it out here. If you're outside the Triangle area, you'll need a repeater directory. They're available from the ARRL and the SouthEastern Repeater Association. At the very least, you can just scan across the band for activity using this chart as your guide (click on the chart for a larger view):
Once you've selected a repeater and dialed it up on your radio, the first thing you should do is... LISTEN for a minute. Repeaters are party lines. Lots of people use them on and off throughout the day, and the one you've selected may be busy with another conversation right now. So listen for a minute. (Does anyone remember what party lines are? Kids, ask your grandparents!)
If the repeater isn't busy, key your transmitter and say something like "KN4AQ listening. Anybody want to chat?" (Use your own call, not mine, please). You could call CQ, but that time-honored method of seeking a contact never caught on with FM operators. Somebody may even tell you your not supposed to call CQ on FM, but you can. What the heck, go ahead and call CQ.
When you release your transmit button, most repeaters will stay on the air for a few seconds, and many will send some kind of beep. Then, the repeater transmitter drops off the air. This little interlude is called hang time. The beep is there to remind everyone to leave a pause between transmissions in case someone wants to break in. Even if there's no beep, leave a pause anyway. Somebody may have just come across a traffic accident and needs the repeater to report it. If nobody leaves a pause between transmissions, they can't break in.
If somebody answers you, then have a good time! You can talk about anything you want – there are not many rules about the content of Amateur conversation. You can't use Ham Radio to conduct your business, but you can talk about where you work and what you do. Prime time TV language has been peppered with some hells and damns, and so has language on some repeaters. RARS discourages that. You're not having a private conversation – you may have lots of listeners, some of them children. Keep that in mind as you choose language and subject matter.
How long do you talk? I see you're catching on to the party-line concept. Maybe somebody else wants to use the repeater when you're done. There's no hard rule. It depends on the time of day (rush hours are prime time for mobiles, evening is also a busy time, while 2 AM is pretty empty), and who else might want to use the repeater. If you've been interrupted several times by others needing the repeater to call someone, maybe you've been on a bit too long.
THREE-WAY RADIO. Not all conversations are strictly two-way. Three, four or five or more Hams can be part of a roundtable conversation (five or more will be pretty unwieldy). A free-wheeling roundtable is a lot of fun... and it poses a problem: when the person transmitting now is done, who transmits next? Too often, the answer is everybody transmits next, and the result is a mess. The solution is simple -- when you finish your transmission in the roundtable, specify who is to transmit next. "... Over to you, Rick. KN4AQ."
WE PAUSE FOR STATION IDENTIFICATION.The Rules say you must ID once every 10 minutes. RARS is big on clear identification when you use our repeaters, but you don't have to overdo it. Give your callsign when you first get on (this isn't specifically required by the rules, but RARS encourages it on our repeaters), then once every 10 minutes, and again when you sign off.
You don't have to give anyone else's callsign at any time, although sometimes its a nice acknowledgment of the person you're talking to, like a handshake.
BREAKING IN. Repeaters are shared resources -- the party-line. There are many times and reasons that a conversation in progress might be interrupted. You might break in to join the group and add your comments on the subject at hand. Someone might break in on you to reach someone else who is listening to the repeater. You might have to report an emergency. How to break in is the subject of debate and disagreement. Here are some suggestions:
Cool down. It doesn't happen often, but it does happen – it's a big world out there, and there are some bad people in it. Some of them find a Ham Radio now and then, and discover the delight of offending an audience. The key word is audience. Deliberate interference and bad language are designed to make you react. The person doing it wants to hear you get mad. They love it. And if they don't get it, they go away, usually quickly. So when you hear the rare nasty stuff on the repeater, just ignore it. Don't mention it at all on the air. Don't mention that you're not mentioning it.
Sometimes a repeater control operator will decide that the best way to handle the situation is to turn off the repeater or one of its functions for a while, but the rest of us should bite our tongues and be silent.
MAKING AN AUTOPATCH CALL. An Autopatch allows you to make local phone calls from your Amateur Radio, through special control equipment and a telephone line connected to a repeater. Before call phones became ubiquitous, autopatch was extremely popular. Today, it's rarely used. But you should know how because... you never know...
The autopatch may require an access code, much like a computer password, but sent in Touch-Tones. Some repeaters have open autopatch, allowing anyone to use it. Their access code is usually just a * (STAR). Other repeaters have closed autopatch. The patch codes are disclosed to members only, although members are encouraged to place calls for hams traveling through town. (RARS' 64 autopatch is open.and there is no access code. Following the procedure below, just ID, let go, key up again and dial the number.)
The procedure for using an autopatch depends on the policy of the repeater's sponsor, and on the design of the control system. This is a basic guide:
First, make sure the repeater isn't busy. If you've just turned on your radio and don't want to wait a minute to see if the channel is active, you might ask "is this frequency in use? KN4AQ." If you have a clear channel, then here's what you do:
On some basic patches, you identify yourself and your intentions ("KN4AQ Autopatch"), dial the access code, unkey your transmitter and listen for a dial tone. Then dial the number.
On other patches, you dial the access code and telephone number as one string, and it stores and then regenerates the number. You then hear it dial and ring. The party you called says hello, and you transmit and talk.
Most people on the telephone end get a little confused by autopatches until they've had some experience with them. When you are transmitting, they can't interrupt you, but they don't know that. So even though they're being rude by interrupting, they will think you are being rude by continuing to talk and "ignoring" them. You can reduce this problem by keeping your comments very short, and releasing your transmit button immediately after your last word.
Another common source of autopatch confusion is the Dead Phone Effect. When you transmit, some noise accompanies your voice on the phone line, even if you have a very good signal into the repeater. And when you stop transmitting, there's usually a little click or pop on the line, then it goes dead silent. The party on the line thinks the phone's gone dead. They will say "hello? hello? Are you still there?" or something like that. We enjoy it.
When you're done with the call, say good-bye, just like on a regular phone call, and let the party on the phone hang up. Then you hit the kill code, which on many autopatches is the # button. And identify again ("KN4AQ, clear autopatch"). Listen to make sure you successfully killed the patch (the repeater may talk to you, or beep, or just drop).
Business calls on an Amateur autopatch are a sensitive area. In September 1993, the FCC relaxed the rules on some business-type communication. You should get a copy of the rules and become familiar with all of them, but here we're specifically talking about 97.113 "Prohibited Communications."
The FCC says you can not use Amateur Radio for your business or employment, but now you can use Amateur Radio for personal communications that involve dealing with a business. The often-cited example is using an autopatch to order a pizza – in the past, this would have been illegal. Now, this kind of call is legal. RARS policy is to keep the business calls to a minimum, and to not disrupt ongoing repeater traffic for a business-type call. Some clubs still prohibit all types of business traffic. Over the years, this has not become a problem. The most frequent (but still rare) violation is hams calling their work to say they're coming in late – that's a no-no!.
Specific RARS autopatch instructions are included later in this GUIDE.
DX! Well, you probably won't be hearing Albania on two-meters anytime soon, but VHF does have it's own form of DX. A few paragraphs ago we mentioned that the RARS .64 repeater had about a 35 mile range. Usually. Sometimes, though, VHF/UHF opens up, and stations can be heard for hundreds of miles. This is another book-length subject. We'll just squeeze in that VHF/UHF band openings are a double-edged sword.
It's exciting to talk to someone 200 miles away, and it's OK, too. But keep in mind that repeaters were designed to cover local territory, not half the country. So when the band opens up, there is the potential for lots of interference as well as lots of fun. Repeaters on the same frequency will suddenly be too close together. You could very easily be keying up two or more of them at once. To be responsible, get to know where your signal is going (a repeater directory will help). Use a directional antenna, minimum power and keep your conversation short.
On .64, we have to be particularly sensitive to another 146.64 repeater in Winston-Salem, about 100 miles west. When the band opens, even just a little, their mobiles begin keying up our repeater, and we begin keying up their repeater. While normally not fatal, this can be irritating. Running minimum power, either mobile or from home, will help. That repeater uses 100 Hz tone full-time, and our antenna and tower put a deep null in their direction, so it's not a big problem anymore.
How much power is too much? Within 15 miles of the .64 repeater (that's every place in Raleigh), two to five watts into a mobile antenna is all you need. 50 watts is excessive. At home, with an antenna up on the roof, 50 watts is really excessive for talking through a local repeater. When the band is open, even a five-watt mobile signal can travel from Raleigh to Winston-Salem. At those times, patience and courtesy will help a lot.
SIMPLEX. This may come as a shock, but you don't have to use a repeater to communicate on two-meter FM. You can use simplex, which means your radio talking to my radio directly. We do have that five to fifteen mile range – much more if we're on our home stations. Why not use it? But don't just pick any old frequency your radio can generate to talk simplex! You may end up on the input of a repeater and interfere with people you can't hear. Use the Band Plan simplex channels:
BAND PLAN? Yes, there is a plan organizing frequency use for two-meters (and, for that matter, every Amateur band). For the most part, band plans are voluntary – the FCC regulates only a few modes and band segments. Band plans for HF are international, and you'll find them on the ARRL web site. Band plans for VHF/UHF are developed by regional coordinating groups. North Carolina is a part of the SouthEastern Repeater Association (usually called SERA, and pronounced like Sarah).
Here's a simple block diagram based on SERA's Two Meter
The complete two-meter band plan is much more detailed than this chart shows. The Repeater and Packet segments are divided into more than 100 individual "channels" for repeaters and simplex operation. For a really complete look at the two meter band, download this PDF file, containing a chart showing every channel in the band plan, with information on the closest repeater to Raleigh for each channel. The chart will print on an 81/2x11 sheet. You'll need your reading glasses (sorry).
(And if you bought a dual-band radio, the chart also shows the UHF repeaters and band plan.)
The two-meter band plan looks complex, perhaps even convoluted, doesn't it? That's because two-meters grew in spurts, a little here, a little there. In the early 1960's, there was just a little AM and SSB activity concentrated just above 145.0 MHz. FM and repeaters were barely getting started, around 146.94 MHz. The rest of the band was empty. FM began to grow, but it was constrained by FCC regulations that let Techs use only 145.0 to 147.0MHz. Satellites were launched, packet was invented, and rules changes moved Techs and repeaters around the band. Everyone needed a slice of the pie, and the result is the band plan you see in the chart. (When I teach a class in the fall, I say that two meters is carved up like a Halloween Pumpkin.)
Check out the frequency coverage of your shiny new two-meter FM handheld. It covers the whole band, doesn't it? But if you use it any-old-where, you might interfere with someone - maybe an SSB operator, or a satellite station, or a repeater input. Please stick to the Band Plan channels. If we all do that, we'll get maximum use and enjoyment out of the band.
EMERGENCIES. Helping to communicate in emergencies is Amateur Radio's #1 reason for existence. Repeaters, especially with autopatch, are excellent tools for emergency communication, and the most frequent type of emergency called in is the traffic accident. Details on the 911-autopatch are included in this publication. And that's why we leave a pause between transmissions – you never know when someone (you) will need the repeater in an emergency.
SKYWARN / ARES. We also use repeaters to help the National Weather Service in an operation called SKYWARN. When severe weather threatens the area, listen to the 146.88 repeater, and follow instructions from the net-control station. Details on Central Carolina SKYWARN are available at their web site.
ARESis the Amateur Radio Emergency Service. During any kind of emergency, ARES operators will be using repeaters for local coordination and traffic-passing. Visit the Wake County ARES web site.
During these operations, the active repeater will probably be closed to regular conversations. But unless a major disaster has hit the area, there will be other repeaters available for regular activity. Ask the net control station for the status of the repeater.
PUBLIC SERVICE. Hams across the country regularly help charitable organizations with communications during fund-raising events like bike-a-thons. Repeaters and simplex are both used for public service events. Their activity isn't too compatible with other hams rag-chewing on the same channel, so during the event a repeater will again be "closed." If you need to make a call or a quick autopatch, call the net control station and most likely you can use the repeater for a minute with no problem. Check the Public-Service web page for details on activities you can help with.
GIVING DIRECTIONS.What's giving directions doing in a repeater operating guide? Just listen for a while, and you'll hear why. We give a lot of directions on repeaters, to locals in an unfamiliar part of town, and to traveling hams visiting the area. And, sad to say, too often we do it badly. One person will give adequate directions, and someone else just has to break in to give his favorite shortcut. Or somebody gives a two-minute long string of street names and landmarks, non-stop. The poor, lost ham who asked will then thank everyone politely, turn off the radio, and pull into a gas station to try again. We literally fall all over each other trying to be too helpful!
If someone has given directions that will get the traveler to her destination, let it be. Make a correction only if the directions are dead wrong (they'll end up in Albania?). If it's your turn to give the directions, keep them short and simple. And it might be helpful to find out where the mobile station is before telling him where to go!
NETS. Repeaters are great places for nets, and there are lots of nets. A net is an organized on-the-air activity. We've mentioned a few already, like SKYWARN and ARES, but there can be many other types – traffic nets, rag-chew nets, specialty topic nets, club information nets, and more. When a net is active on a repeater, the repeater is closed to other activity. The net-control is in charge of the frequency, and all communication should be directed to that station first.
TIMERS. Almost all repeaters have something called timers. A timer is a clock that starts counting when you begin to transmit through the repeater. Typically, this clock is set to time-out after about three minutes. That means that if you transmit continuously through the repeater for more than three minutes, the repeater will go off the air (we call it timing out). Repeater timers usually reset to zero when you, the user, stop transmitting. If the repeater has a beep, the timer probably resets when you hear the beep. So you have to keep your transmissions under three minutes, and always wait for the beep, to avoid having your transmission dumped by the repeater timer.
The three-minute timers are one way to comply with the FCC rules for stations being operated by remote control (most repeaters are remotely controlled). They are not designed as punitive measures for gabby hams... but come to think of it, given the party-line nature of repeaters, and the potential for that emergency traffic, it's a good idea to keep your brilliant monologues a bit shorter anyway. If you must ramble on, orator that you are, don't forget to let the timer reset, and check if somebody else needs the repeater, after a minute or two.
CODED SQUELCH. There are two kinds of Coded Squelch commonly available to Amateurs: CTCSS, commonly called PL® (Private-Line, a Motorola trade name, and also called Subaudible Tone), and DTMF, more generally known as Touch-Tone® (an AT&T trade name). The purpose of coded squelch is to allow special signaling from a transmitter to a receiver, either to turn the receiver on, or to access special functions (like autopatch).
CTCSS (Continuous Tone Coded Squelch System) keeps your receiver quiet on a busy channel until the station you want calls. It adds a "subaudible" tone to your audio, one of 37 very specific frequencies between 67 and 250.3 Hz. Yes, humans can hear these frequencies quite well, so they're "subaudible" because your receiver's audio circuit is supposed to filter them out. A receiver with CTCSS will remain silent to all traffic on a channel unless the transmitting station is sending the correct tone. Then the receiver sends the received audio to its speaker.
In commercial radio service, this allows Jane's Taxi Company and Bob's Towing Service to use the same channel without having to listen to each other's traffic.
In Amateur Radio, many repeaters require users to send the correct CTCSS tone to use the repeater. This rarely means the repeater is closed, for use only by members. More likely it's simply used to avoid having the repeater keyed up by users of another repeater on the same frequency, or by noise at the repeater site.
You can use CTCSS yourself, if you have a decoder in your radio, to silently monitor a busy channel for stations calling just you. Arrange the tone to use in advance, and set your radio to CTCSS decode mode. Have your friend send your tone when she calls. You won't hear anyone else.
But, be sure to turn your decoder OFF before you make a call, or when you answer one, or you might interfere with someone you aren't hearing. Note that many repeaters will not pass these low frequencies, so test the repeater you're planning to use before you count on it as a signal path. Some repeaters will pass the higher tones, but not the lower tones.
DTMF (Dual Tone Multi Frequency, more commenly known as Touch-Tone) is used all over Amateur Radio for autopatching and remote control.