Understanding repeater frequencies

To communicate through a repeater you have to know the frequency on which it’s listening and the frequency on which it’s transmitting. The listening frequency (the one that listens for your signal) is called the repeater’s input frequency, and the frequency that you listen to is called the repeater’s output frequency. The difference between the two frequencies is called the repeater’s offset. The combination of a repeater’s input and output frequencies is called a repeater pair.

As Figure 9-2 shows, repeater pairs are organized in groups, with their inputs in one part of the band and their outputs in another, all of them having a common offset. Each pair leapfrogs its neighbor, the channels all spaced equally in frequency; this is the channel spacing. The input channel may be at a lower frequency than the output, or vice versa.

Figure 9-3 shows the locations of repeater segments on the five primary VHF/UHF bands. The 6 meter band has three groups of repeaters: 51.12 to 51.98 MHz, 52 to 53 MHz, and 53 to 54 MHz. The 2 meter band also has three groups: 144.6 to 145.5 MHz, 146.01 to 147 MHz, and 147 to 147.99 MHz. The 70 cm band hosts one segment with a large simplex segment in the middle: from 440 to 449.99 MHz. The 222 and 1296 MHz bands have a single group. Repeaters are allowed on the 902 MHz and 2304 MHz bands but aren’t common. If you have a license with HF privileges, you may want to give the 10 meter FM repeaters a try. They have output frequencies between 29.610 and 29.700 MHz and an offset of –100 kHz.

Finding repeater frequencies

Not all channels are occupied in every area. Also, around the country, some local variations exist in channel spacing and, in rare cases, offset. To find out where the repeater inputs and outputs are for a specific area, you need a repeater directory (see Chapter 8). You’ll also find a growing number of repeaters in the 902-928 MHz (33 cm) band.

The online directory at www.artscipub.com/repeaters/welcome.html is a good resource for locating repeaters in your area. It also provides information about any access codes, whether the system is digital or analog, and if it is part of a network of repeaters, as discussed later in this chapter.

If you don’t have a repeater directory and are just tuning across the band, try using Table 9-1, which lists the most common output frequencies and repeater offsets to try. Tune to different output frequencies, and listen for activity.

Most FM VHF/UHF radios are capable of scanning so they can switch among channels rapidly, stopping when they receive a signal. Scanning allows you to monitor several repeaters for activity without having to switch channels manually. You can learn more about scanners and scanning in my Dummies book Two-Way Radios and Scanners For Dummies.

Set your radio’s offset appropriately for each band, and tune to the center frequency of each channel to avoid signal distortion from being off-frequency.

There are two geographic restrictions for U.S. hams using repeaters on the 440 MHz or 70 cm band. Operating on some frequencies is not allowed in Canada and the FCC rules restrict U.S. hams from operating near the border to prevent interference. Look up “Line A” in your Technician study guide for more information. Hams near U.S. Air Force bases with Pave PAWS radars may also find repeater operation curtailed. The 70 cm band is shared with the primary radiolocation and military users so hams have to avoid interference with these important installations.

Using tone access

Regardless of what it’s called, tone access works this way: When you transmit to a repeater, a low-frequency tone (between 67 Hz and 254.1Hz) is added to your voice. (You can find a list of these tones and how to select them in your radio’s operating manual.) When the repeater receives your transmission, it checks your transmitted signal for the correct tone. If it detects the correct tone, the repeater forwards your voice to the repeater output. This system prevents interfering signals from activating the repeater transmitter; those signals won’t carry the correct tone signal and aren’t retransmitted.

For a more detailed discussion of tone access, see The ARRL Handbook or the article “Decoding the Secrets of CTCSS,” by Ken Collier (KO6UX), at olyham.net/library/CTSS%20Secrets.pdf.

Most radios also offer tone squelch, which uses the same set of tones to control the squelch circuit. It works just like the repeater receiver’s tone access, in that only signals with the right tone are output as audio. Most of the time, the same tone is used for both transmitting and receiving.

Many recent radio models also have a tone-decoder function that detects which tone a repeater is using. If your radio doesn’t have this function, and you don’t know the correct tone, you can’t use the repeater. How can you find out what the proper tone is? Check a repeater directory, which lists the tone and other vital statistics about the repeater. When you determine the correct tone, either via the tone-decoder function or the repeater directory, you can program your radio to send the correct tone and activate the repeater.

Using Digital Coded Squelch (DCS)

DCS is another method of reducing interference. It allows you to hear only audio transmitted by selected stations. DCS consists of a continuous sequence of low-frequency tones that accompanies the transmitted voice. If your receiver is set to the same code sequence, it passes the audio to the radio’s speaker. If the transmission uses a different code, your radio remains silent.

Most people use DCS to keep from having to listen to all the chatter on a repeater, hearing only the audio of others who use the same DCS sequence, such as friends or club members.

Not all repeaters pass the tone access or DCS tones through to the transmitter and may filter them out.

Time-out

Repeaters have a time-out function that disables the transmitter if the input is busy for more than just a few minutes (typically, three). This function prevents the transmitter from overheating and also keeps a long-winded speaker from locking out other users. If you stop transmitting and no repeater signal comes back, you may have “timed out” the repeater. Just let the repeater rest for 10 or 15 seconds until the receiver is reenabled and the timer resets. There’s no need to be embarrassed about timing out a repeater (unless you keep doing it), because it’s a rare ham who hasn’t done it.

Autopatch

Some repeaters have a feature called autopatch, which allows a repeater user to make a telephone call through the repeater. You may think that mobile phones make autopatch unnecessary and mostly, you’re right! Autopatch is not widely used today. However, even in a world full of mobile phones, autopatch can still come in handy if your mobile phone’s battery goes out or the network malfunctions.

All autopatch calls occur over the air; they’re not private.

Remote receivers

Within a local or regional area, many repeater systems may use remote receivers that relay weak signals from outlying areas back to the main repeater transmitter. The relayed signal is transmitted over a control link, which is a dedicated transmitter and receiver operating on a VHF or UHF band. It’s not unusual for a repeater to have three or more remote receivers. To link repeaters over wide areas and long distances, however, it is common for repeater systems to use the Internet.

Open and closed repeaters

If you purchase a repeater directory, you may see some repeaters that are marked as closed, meaning that they’re not open to the ham-radio public. Some repeaters are closed because they’re dedicated to a specific purpose, such as emergency communications. Other repeaters are intended to be used only by members of their supporting group.

Rest assured that you can use a closed repeater in case of emergency, but respect the wishes of its owners, and don’t use it for casual operation. If you aren’t sure whether a repeater is closed or not, transmit to it and say something like this: “This is NØAX. Is a control operator monitoring?” If you get a response, that person is the one to ask.

Using radio programming software

The manufacturers of portable radios recognize that having so much flexibility and so many features can make setting up a radio a long process. Most of them offer a simple software package to help you configure your radio. You can do it through the radio’s keypad or front panel, but this is often a cumbersome process for all but the basic steps, particularly creating easy-to-read labels for channels and storing messages.

Software for programming radios is also available from independent groups. Two of the most popular are from RT Systems (www.rtsystemsinc.com) and Chirp Software (chirpsoftware.com). Figure 9-4 shows a programming table for the popular Wouxon KG-UV6 handheld radio. The RT Systems software programs each memory channel with frequencies and all the necessary control or access code information. This is far easier than entering each channel through the radio’s small keypad! Chirp is a free open-source programming package. RT Systems is not free, but it is a more complete programming system with cables and USB adapters.

The typical programming package includes a CD-ROM or downloadable file and a programming cable that connects to a PC. The interface to most radios is a serial port (RS-232 or COM). Few portable or mobile radios have USB interfaces as of 2018. You may need a USB-to-COM port adapter if your PC doesn’t have a COM port. The cable usually plugs into some kind of audio jack that does double-duty for programming. Make sure you have the right cable as the required connections are usually different than standard audio cables and the software won’t work.

Check for sales and package deals, particularly at the bigger hamfests, where vendors may include programming software and cables in a single package at a discount.

The process begins with installing the software and following the instructions about when to connect your radio and turn it on. The software then “detects” your radio (it’s not plug-and-play, but similar). If necessary, you can “read” your radio and transfer all its internal channels and other setup information to the software. At this point, save your radio’s data (see the software help function) in the event there is a mistake or other problem and you want to return the radio to its previous configuration.

Now go through the process of selecting all the options and features your radio offers. This is a good time to enter all the local repeaters and simplex channels with a label so you don’t have to remember all the frequencies. For example, my local St. Charles Radio Club primary repeater is labeled “SCARC1.” You can also program in call signs if that’s easier to remember. Be sure to get all the access control tones and codes in there, as well. Then save a copy of all the information so you can reload it later, if necessary. I use the radio model number and date as the file name, such as VX8-7-OCT-2017.

Most 2 meter (VHF) radios can also receive frequencies close to the ham bands, such as the common 136 to 174 MHz. When setting up your radio, program a few channels to receive the NOAA National Weather Service broadcasts of weather information and severe weather alerts (www.nws.noaa.gov/os/marine/wxradio.htm). There are seven channels just above 162 MHz, WX1 through WX7, and at least one will be receivable almost anywhere in the U.S. If your radio has “extended receive,” it may also be able to receive commercial wideband FM broadcasts (88–108 MHz), aircraft Civil Aviation Band channels (wiki.radioreference.com/index.php/Aircraft, 108–136 MHz, AM), and even AM broadcasts (550–1700 kHz, AM).

Cloning radio configurations

Most radios can also be “cloned,” that is, the configuration of one radio can be transferred to another radio of the same model without having to do the full programming operation. This time-saving feature can be very useful in the field where a PC with the host software isn’t available. The ability to clone radios is a good reason for public service or emergency response teams to use radios of the same type.

Your manual shows the exact the steps for your radio. The usual procedure involves turning both radios off and holding down a switch or key when turning the power back on. The user’s manual provides the necessary instructions and the order in which each step is to be performed. The cloning process then transfers the necessary information from the “master” radio. The radios notify you when the process is finished. You then cycle power on each radio, and the job is done!

You must use the right cable for cloning. Cloning cables or adapters are often available with the software programming package. The order of the required steps in the manual must be followed exactly to start the process and to be sure you clone the right radio! Don’t interrupt the cloning process or the radio being reprogrammed may require a complete reset operation.

Voice over Internet Protocol (VoIP) systems

Two ham radio systems link repeaters via the Voice over Internet Protocol (VoIP): EchoLink (www.echolink.org) and the Internet Relay Linking Project (IRLP; www.irlp.net). Voice signals and control information is exchanged in much the same way that the Skype web communication application does. Figure 9-5 illustrates the basic IRLP system.

The links between repeaters and individual stations in the IRLP and EchoLink systems are controlled manually by the system users. When you’re connecting to either system beyond your local repeater, you must enter an access code manually using the radio’s keypad. The code identifies the repeater system you want to use; then the system sets up the connection and routes the audio for you. When you finish, another code or a disconnect message ends the sharing. This overview is very simplified, of course, and both systems offer useful features beyond simple voice links.

EchoLink systems can also be accessed directly from a computer via the Internet, so users don’t have to have a radio at all, making EchoLink a popular way to communicate if you don’t have a radio handy or are traveling away from your home repeater but still want to have contacts with local stations. The best guide for learning about and using EchoLink is the Nifty E-Z Guide to EchoLink Operation by Bernie LaFreniere, N6FN (www.niftyaccessories.com/EchoLink_book.php).

An IRLP node is a regular FM repeater with an Internet link for relaying digitized voice. A user or control operator can direct an IRLP node to connect to any other IRLP node. When the node-to-node connection is made, the audio on the two repeaters is exchanged, just as though both users were talking on the same repeater. It’s common for a ham in Europe to communicate with a ham in New Zealand, for example, with both parties using handheld radios that put out just a watt or two.

You can also connect several nodes by using an IRLP reflector. The reflector exchanges digitized audio data from any node with several other nodes in real time. Even a user who doesn’t have a radio can join in by logging on to an IRLP reflector or node. (All users who create radio transmissions have to be licensed, however.)

To use the IRLP system you don’t need anything more than your radio, the IRLP system’s control-tone sequences for your repeater, and a list of the four-digit node on-codes that form the IRLP address of an active IRLP repeater. Using the IRLP system is described at www.irlp.net/guidelines.html. The introductory article at www.eham.net/newham/irlp gives a good overview of the system, as well.

The D-STAR system

D-STAR is not only a type of repeater system, but also a complete set of digital communication protocols for individual radios. D-STAR’s digital voice protocol must be used by everyone on the system, requiring the use of radios that are compatible with D-STAR. D-STAR’s fully digital system in Figure 9-6 also enables data-only operation, and many software applications have been developed to use that capability.

D-STAR repeaters are connected to the D-STAR system through gateways: computers that are connected to the repeater and to the Internet. Hams establish links from one D-STAR repeater to another by entering call signs into their D-STAR radios. The D-STAR system’s servers use these call signs to look up the low-level Internet network addresses of individual repeaters. Then the system directs each repeater to make the connection and share the voice data.

Call-sign lookup is an interesting feature because hams don’t have to know where another ham is to contact that person; the D-STAR system remembers where each ham last used a D-STAR repeater. Calls to a specific ham are routed to his or her last-known D-STAR repeater. This feature is a lot like the mobile phone system, which keeps track of where your phone is connected to the network so it can route your calls to that point.

The WIRES-X system

This system shown in Figure 9-7 is similar to the IRLP and EchoLink systems. Individual stations are connected to the Internet through WIRES-X routers, creating a WIRES-X node. The node has a unique ID that can be accessed by other WIRES-X nodes through the Internet.

The radio connected to the router can be used directly by a user so that talking into the microphone communicates through the Internet without transmitting an RF signal. Another radio, such as a nearby handheld or mobile radio, can communicate over the air to the node-connected host radio and be connected to other WIRES-X nodes through the Internet as well. This creates user-to-user communication.

On the Internet, computers can host a WIRES-X room, like an Internet chat room. When a node is connected to a room, the node user hears all the audio from every node connected to that room. This supports round-table contacts and nets. Rooms can be semi-permanent and have a theme, such as “DXing” or “Local Traffic” or they can be temporary, created for a specific need.

The DMR system

The DMR or Digital Mobile Radio system was originally designed by Motorola for shared communications systems used by public safety, government, and commercial users. It operates similarly to the earlier “trunked” systems that were intended to support fleet and department-level operations with many users. Hams adapted this technology as they had done with analog FM systems decades before. Because DMR was designed for commercial use, much low-cost equipment is available, although the user interface and programming are not as user-friendly as equipment designed for ham radio. DMR’s popularity is increasing rapidly.

In the DMR system (see Figure 9-8), each radio connects to the local repeater and is assigned one of two alternating time slots during which it can transmit and listen to the digital voice stream of the repeater. (DMR digital voice transmissions consist of two alternating streams of data. This is referred to as TDMA — Time-Division, Multiple Access.) Much like a mobile phone and its host system, the radio must request permission to transmit from the repeater.

The repeater is in constant communication with a local or regional “master” that manages all the data streams from the repeaters connected to it. This allows the DMR system to create “talk groups” so that groups of users can share the same repeater without interference. In addition, masters are also in communication with central “bridge” systems, creating networks that route communications between thousands of users. There are two primary bridge systems today (2017), the MARC (Motorola Amateur Radio Club) and the Bridge-Com systems.

There are numerous other features that make DMR the most flexible amateur communications network currently in use. Talk groups can be local, regional, or even international in scope. Various levels of authorization and authentication can be created. If you are interested in the technical details of DMR, the Amateur Radio Guide to Digital Mobile Radio (DMR) by John Burningham (W2XAB) is an excellent introduction (www.trbo.org/docs/Amateur_Radio_Guide_to_DMR.pdf).

HF bands

Below 30 MHz, all the bands have a similar structure. CW (Morse code) and digital modes occupy the lower third (more or less), and voice modes occupy the upper two-thirds (less or more).

Figure 9-9 shows where you can expect to find contacts of different styles on a typical HF band. You find the ragchewers mixed in with the long-distance (DX) contacts at the low end of the band. This is oversimplified, of course, but gives you an idea of how to start.

You can always find CW at the low frequencies of the HF bands. The faster operators tend to be at the bottom of the bands, with average code speed dropping slowly as you tune higher.

Digital signals nearly always cluster close to the published calling frequencies listed in the band plans for that particular mode unless a major contest or some other event is going on. Stations spread out higher in frequency from there.

You may think that ragchewers are buffeted from all sides, but that’s not really the case. Ragchew contacts take place all the time, so they tend to occupy just about any spare bit of band. To be sure, in the case of disasters (when a lot of nets are active), major operations from rare places, or weekends of big contests, the bands may seem to be too full for you to get a word in edgewise. In those cases, try a different band or mode; you’ll probably find plenty of room.

When the bands sound too full to use, try reducing your receiver’s sensitivity. It could be overloading or just making it too easy for you to hear noise. Turn off the preamp, turn down the RF Gain, or turn on the attenuator … or all three! You will probably be able to hear just fine, and the noise and “crud” will be a lot less objectionable. While you’re at it, turn off the Noise Blanker, which can generate distortion all by itself if strong signals are present.

The FCC can declare a communications emergency and designate certain frequencies for emergency traffic and other communications. Keeping those frequencies clear is every amateur’s responsibility. The ARRL transmits special bulletins over the air on W1AW, by email, and on its website if the FCC does make such a declaration. The restrictions are in place until the FCC lifts them.

VHF and UHF bands

On the VHF and UHF bands, you usually find ragchewing in the repeater sections, although wide-open spaces for an SSB, CW, or digital conversation are available in the so-called weak signal segments. Scan the wide-open spaces away from the repeater channels and you may come across a local group using a frequency as their “watering hole.” Join in and say hello!

The bottom portion of the VHF/UHF bands is referred to as weak signal, although that’s really a misnomer. The reason for the name is that contacts via CW and SSB can be made with considerably weaker signals than on FM. Most of the weak-signal signals you hear are sufficiently strong for excellent contacts, thank you!

Table 9-2 lists the calling frequencies and portions of the VHF/UHF bands. The operating style in this portion of the bands is similar to HF as far as calling CQ and making random contacts go, but the bands are far less crowded because propagation generally limits activity to regional contacts.

The digital repeater networks create Internet-like ways for people with similar interests to find each other. For example, the WIRES-X network has “rooms” and the DMR system has “talk groups.” These function similarly to the analog FM calling frequencies in that they are great ways to connect with other stations with a minimum of searching.

Good times

Assuming that you’re tuning an open band (with signals coming in from various points), when is a good time to ragchew? First, consider the social aspects of your contact timing. Weekdays generally are good days to ragchew, especially during the daylight hours, when hams who have day jobs are at work or student hams are in class.

You may want to revisit Chapter 8 when considering what band is best to use. If you like to talk regionally, you can always use a repeater or one of the low-frequency HF bands. For a coast-to-coast talk, one of the high-frequency bands is your best bet. The better your antenna system, the more options you have.

Lots of hams do their operating on weekends, but that’s also when special events and contests are held. Be prepared for a full band every weekend of the year. The silver lining of this cloud is that plenty of hams will be on the air for you to contact. If you know that one mode or band is hosting some major event, you can almost always find a quiet spot on another mode or band.

The WARC bands (see the nearby sidebar “What’s a WARC?”) never have contests and usually are wide open for ragchews and casual operating.

Not-so-good times

Because a ragchew can last for a long time, pick a time and band that offer stable conditions. Propagation changes rapidly around sunrise and sunset. Local noon can be difficult on the higher bands. Don’t be afraid to make contacts at any old time, though. You may surprise yourself and find out about propagation from the best teacher: experience.

Because weekends are busy times, you should check the contest and special-event calendars (see Chapter 11). A little warning keeps you from being surprised when you get on the air and allows you to be flexible in your operating.

It can be a very different time of day at the other end of a DX contact.

When the bands seem to be frustratingly full, here are some helpful strategies that keep you doing your thing:

• Try a nontraditional band. Most nets and all contests are run on the traditional bands. The WARC bands almost always have sufficient space for a QSO.
• Try a different mode. Very few big contests have activity on more than one mode. You can change modes and enjoy a nice ragchew, too.
• Be sure that you know how to operate your receiver. Cut back on the RF gain, use narrower filter settings, know how to use controls such as the IF Shift and Passband Tuning controls, and generally be a sharp operator. You can remove much interference and noise just by using all the adjustments that your receiver provides.
• Always have a backup plan. There’s no guarantee that any particular frequency will be clear on any given day. Hams have frequency freedom second to none, so use that big knob on the front of your radio.

Receivers are very sensitive and can easily be overloaded by strong signals, causing distortion that sounds like interference. You can make a huge improvement in listening quality by ensuring that your receiver is operating linearly. Start by turning off the preamp and noise blanker. Turn down the RF Gain control until the signal you’re listening to is at the lowest comfortable level; you’ll hear the noise background fade away. You can even switch on the receiver’s attenuator to knock down strong signals even more. Use the minimum amount of sensitivity required to make the contact, and you’ll enjoy listening a lot more.

Calling CQ for a ragchew

Although responding to someone else’s CQ is a good way to get started, it’s also fun to go fishing — to call CQ and see what the bands bring.

The best CQ is one that’s long enough to attract the attention of a station that’s tuning by but not so long that that station loses interest and tunes away again. If the band is quiet, you may want to send long CQs; a busy band may require only a short CQ. As with fishing, try different lures until you get a feel for what works.

On voice modes, the key is in the tone of the CQ. Use a relaxed tone of voice and an easy tempo. Remember that the other station hears only your voice, so speak clearly, and be sure to use phonetics when signing your call. Sometimes, a little extra information — such as “from the Windy City” — helps attract attention. Don’t overdo it, but don’t be afraid to have a little fun.

Be sure your transmitted audio is not distorted and that your RF signal is not splattering. Have a friend listen in and make sure you have a clear, clean signal. Take note of your transmitter settings and how the meters respond when you’re speaking.

Evaluate on-the-air technique as you tune across the bands. Consider what you like and dislike about the various styles. Adopt the practices you like, and try to make them better; that’s the amateur way.

Sharing a ragchew

Hams come from all walks of life and have all kinds of personalities, of course, so you’ll come across both garrulous types, for whom a ragchew that doesn’t last an hour is too short, and mike-shy hams, who consider more than a signal report to be a ragchew. Relax and enjoy the different people you meet.

If your radio has the capability to listen between CW dits and dahs (which your operating manual calls break-in or QSK), use it to listen for a station sending dits while you are CQing. That means “I hear you, so stop CQing and let me call!” Then you can finish with “DE [your call] K,” and the other station can call instead of waiting.

Roundtables — contacts among three or more hams on a single frequency — are also great ways to have a ragchew. Imagine getting together with your friends for lunch. If only one of you could talk at a time, that would be a roundtable. Roundtables aren’t formal, like nets; they generally just go around the circle, with each station talking in turn. Stations can sign off and join in at any time.

Brag tapes

Rather than type everything each time, common information such as operator or station information is saved in a brag tape file. A typical brag tape (also known as a macro) has information about the operator or the station or something else that is sent frequently enough to have recorded and not have to type every time.

For example, here’s a typical brag tape with station details:

• Rig: IC-7300 and MFJ-939 Auto-tuner
• Power: 25 watts
• Ant: HF-6V Vertical with 32 radials
• Software: FLDIGI 4.0.9
• OS: Windows 10

You can have brag tapes for all sorts of things and have them ready to play back with a single key press. If you find yourself having to type in the same information over and over, perhaps putting it in a brag tape is a good idea.

Brag tapes come from the old days of electromechanical teleprinters when “tape” literally meant “paper tape”! RTTY operators usually had several rolled up and ready to go with one loaded into the tape reader for CQs and that sort of thing. Today, brag tapes are typically a file on a computer that is sent with a key press.

Concluding the QSO

Finally, the end of a digital mode QSO looks a lot like the end of a CW QSO which is a lot like the end of a phone QSO. Refer to the section “The long goodbye” in Chapter 8 for that discussion.

Remember that most software in use today has a screen width of about 80 characters. If you don’t break up your lines of text, the characters may scroll out of the receive window of the receiving station! Keep your lines of characters reasonably short, like this example that shows a CQ message consisting of two lines. The “K” at the end of the second message is a prosign used for both Morse and digital modes to mean “I am done transmitting” when on voice you would say “Over”:

• CQ CQ CQ de NØAX NØAX NØAX (new line here)
• CQ CQ CQ de NØAX NØAX NØAX K (new line)

Many operators report good luck with 3-by-2-by-3 CQs (CQ CQ CQ de NØAX NØAX, repeated three times). It is also common to end with “PSE K” (please respond now, go ahead) instead of the plain “K.”