Eslabón de la industria

Missed something?

If the receiving station didn’t receive all of the message, he will ask for fills. If the street was garbled, the receiving station will simply ask “street?” Perhaps the last part of the text wasn’t copied. The receiving station will ask you for “all after arrived.” The receiving station missed everything after the word “arrived,” so you will have to repeat the part of the message after “arrived.” Don’t repeat the whole message!

Common abbreviations used on CW for fills are AA (all after), AB (all before) WA (word after), WB (word before), or BN (between). Digital communication modes have hand- shaking between the transmitting station and the receiving station to ensure that all of the message is received. Receiving a Message

We’ve already covered “fills.” On phone, most stations let their VOX drop so that they can hear between sentences so if you miss something, you can easily let them know. On CW, most experienced ops use break-in, which lets the transmitting station hear between words, if not between letters! Even without break-in, the transmitting station can be broken when he pauses between AAs or BTs.

Relaying a Message

You know how to receive a message and how to transmit one. Relaying is a simple combination of both. You send the message just as it was received. The only thing you can change is to add a corrected check only if there is a problem with the word count. You send the original check corrected to the word count you have.

Delivering the Message

Suppose you pick up some traffic on a net that’s for someone in your immediate area. Delivery is the object of all message handling and a message should be delivered as soon as it is within non-toll telephone range. A good way to start out is to say, “This is Amateur Radio operator Bob Smith, and I’ve received a greeting message from a relative of yours.” Speak clearly and offer to handle a reply. If you can’t deliver the message for some reason, send a service message back to the originating station, explaining that the message can’t be delivered.

9.2 • The National Traffic System

The National Traffic System includes four different net levels which operate in an orderly time sequence to effect a definite flow pattern for traffic from origin to destination. A message flows through the National Traffic System in a manner similar to an airline passenger who starts out in a small residential town with a destination across the conti- nent in another small town. He has to change carriers many times in the process, starting with a local ground convey- ance to a feeder airline, to a transcontinental airline, to another feeder airline, then local transportation to deliver him to his destination. In a very similar manner, the trans- continental message starts with the originating station in a local net, is carried to the section net, the region net, the area net, via Transcontinental Corps (TCC) to a distant area net and then back down the line to delivery.

Of course the message, like the passenger, can “get on” or “get off” at any point if that’s the origin or destination. Thus, a message from, say, New York to Detroit would

never get on TCC, but would “get off” at area level. A message from San Francisco to Los Angeles would not go beyond region level, and one from Syracuse to Buffalo would remain inside the section net.

Messages may also be passed through NTS-affiliated Local and Section traffic nodes that employ digital modes such as AMTOR and packet, with store-and-forward capa- bilities and bulletin board operations. Long hauls can be made by NTS Digital Stations at HF, that interface with Section traffic nodes, and the traditional nets of the system. A detailed explanation of the National Traffic System is found in the Public Service Communications Manual, pub- lished by the ARRL.

9.3 • Emergency Net Operations

This discussion of net operations is from the 1996 Northern Florida ARES Plan. Thanks to Rudy Hubbard, WA4PUP, Northern Florida Section Manager and George Thurston, W4MLE, Northern Florida Section Emergency Coordinator.

Section Nets

Emergency nets function both as traffic nets and as an ARES official liaison net. A Section National Traffic System (NTS) net becomes an emergency net frequency when the Section Emergency Coordinator or Net Manager alerts the Emergency Net. During operation, the net uses the name Northern Florida Emergency Net

The Northern Florida Emergency Net operates on the frequency of the Northern Florida Phone Net and the Northern Florida ARES Net (3950 kHz), or their alternate (7254 kHz), plus or minus a few kHz as necessary to accommodate conditions. The Emergency net may oper- ate simultaneously on both the 40-meter and the 75 meter frequencies, each with its own Net Control and its own set of side frequencies. The “prime net” is where net control is. Frequencies on either side of the primary net, used for exchanging traffic, are called “secondary nets” or “side frequencies.” The primary frequency and all its secondary frequencies are referred to together as “the net.”

Each net is called the “Northern Florida Emergency Net.” They are distinguished from each other by reference to the band.

Net Management

The Emergency NM is directed by the SEC. During Emergency Net operation, the managers of the Phone Net and the ARES Net alternate as Emergency Net Managers, each having full authority while on duty. Between them, they cover the full 24-hour period of operation when neces- sary, arranging their duty periods to suit their mutual convenience. His/her duties include appointment of Net Control Stations (NCS), keeping attendance records and maintaining a work log of net activity while in emergency session. During simultaneous operation on both frequen- cies, the NM has overall responsibility for both nets, and designates and Assistant NM to supervise operations on one of them.

Responsibilities of the Net Manager include:

* Overall supervision of the net’s operation to maintain net discipline and efficiency, intervening as necessary to smooth out procedural problems.

* Arranging relief for NCS operators at reasonable inter- vals.

tive control of the net.

* Notifying the SEC or SM when, and if, the net encoun- ters persistent destructive interference.

* Recommending timely measures to the SEC to im- prove over-all operation of the ARES system in the existing emergency.

Secondary Nets

Traffic should not be handled on the primary frequency of the Emergency Net except during periods of slow opera- tion. If the net frequency is continuously busy, it blocks the listing and dispatching of traffic and the conduct of other business. Mobiles, weak stations or those with MAYDAY or SOS traffic may have trouble being heard.

Net Control

Net control of a Section or District Net should not be located in the disaster area, where it would be subject to too many adverse factors. Rather, NCS should be located so as to hear stations in the impacted area as well as possible. The Net Manager should select net control operators on the basis of signal quality/strength and operating skills, and should take propagation into account. NCS will appoint relay stations as necessary.

A two-hour emergency net control shift is the norm, but the NM may adjust this duty cycle as convenience and necessity require. Gateway stations should not be used as NCS, except during very slow activity hours or when their Gateway services are not being utilized.

If destructive QRM occurs on an Emergency Net fre- quency, the SEC should be notified promptly by telephone or radio (but not on the net frequency). If the NCS is unable to move the troublesome station by polite request, the SM or SEC may ask the FCC to intervene.

Free Mode Operation

Free mode is always the preferred method of net control, conditions and traffic loads permitting, i.e., when net busi- ness is light. The NCS remains silent except to identify itself and the net at nine-minute intervals, and to respond

to calls. Free mode or actively directed, NCS is always in charge of the frequency. Member stations still address NCS before calling another station, but the frequency is allowed to be idle between burst of activity. Weak stations have a better chance to be heard when the frequency is not continuously occupied. Directed mode is used when nec- essary to maintain decorum, reduce confusion and/or to facilitate traffic management. When business gets brisk enough to require an NCS, directed status resumes.

Net control operators should not maintain a constant drone, even in directed mode. This can interfere with stations trying to contact the net. During free operation, NCS should make a brief announcement about every nine minutes, identifying him/herself and the net. Something like: “This is NZ4ZZ, net control for the Northern Florida Emergency Net, in free mode operation.” If curious opera- tors ask what’s gong on, NCS should have a brief, “canned” response ready, such as, “We’re supporting the National Weather Service in a weather emergency.”

NCS should respond immediately if other stations, not realizing the frequency is occupied, try to begin operation there. A polite but firm request to respect the emergency frequency is usually all that’s required. A slight shift in frequency by the emergency net should be made if reason- ably necessary.

Frequencies

Section-wide coverage during an emergency will be maintained using nets on 75 and/or 40 meters. The Net Control operator on duty will decide whether to keep the net on its current frequency or to shift to its designated alter- nate frequency, or to move up or down a few kHz to avoid QRM.

Note: The practice of using “BREAK” or “BREAK BREAK” to announce distress traffic should be strongly discour- aged; it has no universally understood meaning. Always use the international standard “MAYDAY” or universally understood “EMERGENCY” to announce traffic of life-or- death importance. The standard CW signal is “SOS,” sent as a single character—not spaced as three letters.

Chapter 10