Activation – Ready, Set, Go

Denver ARES is a response based organization and as such we have standard guidelines that we follow. This enabled everyone to know exactly how to prepare, what to do, and when to do it.

All members are required to be ready to respond by keeping a simple ‘go-kit’ prepared to be used during an activation.  But what exactly happens when a call comes in?

Ready Set Go model

The Ready, Set Go model of staged activation. Ready: Be prepared. Set: Activation is likely. Go!

Activation

An incident can be for a planned event, an exercise, or for deployment to an incident.

Denver ARES Members will not self-activate!

Members will be activated through one of the methods below. For most incidents this activation will come in from the served agencies to the EC and members will be activated by the EC or the AEC using the CVM system*. The requestor will provide situational awareness and specific communication needs (Know Before You Go http://denverares.org/wp-content/uploads/2020/01/KnowBeforeYouGo.pdf).

Denver ARES uses a three stage activation process: Ready, Set, Go!

Ready

The Ready stage is often 24 to 48 hours in advance of an activation. This can be triggered by a scheduled exercise, a planned event, or a ‘heads up’ from a served agency. Notification is done via email or during a regularly scheduled net. This may only be a ‘stand-by’ notification and may not result in an activation. The ready state does not call for any changes to a member’s daily routines.

Upon receiving a Ready Activation the members should:

  • Review equipment needs and expected activity
  • Confirm their Go Kit status, gather any expected forms.
  • Charge backup batteries, replenish any consumables.
  • Confirm correct programming of radios.

Set

The ‘SET’ stage is typically 4 to 24 hours in advance of the activation. This can be triggered by expected weather conditions (Storm Prediction Center of Weather Watches), scheduled stage for pre-planned events or exercises, or expected needs from a partner agency. This indicates that there is a high probability of full activation.

Activities should include:

  • Notify school, work, etc. of possible absence.
  • Charge primary batteries
  • Review (practice) skills, confirm capabilities.
  • As much as possible, monitor primary radio frequencies for updates.

Go!

The Go stage notification is typically done 0 to 1 hour before activation via CVM notification service. In the case that there are communications disruptions, phone trees or direct radio notification may be used instead.

This notification will include specific information about when and where to expect an Incident Briefing, and may include specific task assignments.

Specific activities include:

  • Arrange travel, gas up the car.
  • Load your Go Kit.
  • Complete (if possible) the Know before you go form.
  • Check into the Resource / Command Net.
  • Dispatch to Incident Briefing location or to assigned station.

Notes:

  • In the case of an activation by the Denver Office of Emergency Management (OEM) the specially trained EOC team will receive an activation notification directly from the EOC activation system.

DMR For EmComm

What is EmComm?

EmComm, or Emergency Communications is the practice of providing communication services during emergency response, especially in situations where traditional communication modes may not be available.

The primary role of ARES is to support the emergency management community (responders, relief and recovery agencies) with communications during times of emergency and disaster when normal communications are unavailable or overwhelmed.

We are communicators not first responders. If you arrive at the scene of an emergency just as the sirens are quieting, check in, keep your mouth shut ,and get out of the way until you get an assignment. We do not provide first aid, transport victims, provide traffic control or any other function normally provided by public service agencies, nor are we running the show. We DO provide communication when public service communications systems are overloaded. We do not “self deploy.” We deploy when a partner agency requests our services.

Many hams think of ARES as a simple extension of the “talk time” in the hobby. This is not true. ARES are organizations that continually learn, train, and develop the skills needed to be part of the emergency response machine. We always need more trained operators that are willing to learn to communicate rather than just talk. Do you have the time and the drive to do it well?

The goal is to provide trained operators that have learned to communicate accurately, clearly, and concisely in a timely fashion regardless of the obstacles in the event. One tool for communication is DMR or Digital Mobile Radio.

What is DMR?

DMR is a radio protocol that uses digitally encoded signals instead of traditional analog signals. This is much like the difference between playing an old LP record that directly recorded analog sound versus playing a CD where the audio is encoded as bits and bytes – these bits and bytes are what is transmitted via the radio signal.

Why use it?

There are a number of reasons that make DMR a good choice for EmComm:

  1. Unlike analog radio – there is no ‘fade’ as a signal gets weaker. As long as the signal gets through the audio is clear and readable. This cuts down on the need to re-transmit messages when there are high levels of noise.
  2. DMR is much more efficient in terms of bandwidth. Using much narrower slices of the radio spectrum, and time slicing the available frequencies (more on this later) as many as four conversations can be held using the same bandwidth that one analog communication would take.
  3. DMR can be more capable – since the exchanges are digital text and data can be exchanged alongside the voice exchange. This can include position information, short text messages, and more.

But there are also a few downsides – most significant is the fact that a DMR exchange either works or it fails – completely. With analog radio, a trained operator can pull voice traffic out of very noisy backgrounds. This can be important in an emergency. With DMR, you generally either have a clear voice with little or no background, or you have nothing – literally nothing. So lets talk about how DMR does its thing.

DMR – How it works

DMR does its magic by squeezing your conversation into a really small space. It does this by converting the audio to digital data. Then, since the binary data does not require as much bandwidth as a voice, DMR only needs 6.5kHz instead of the 12.5kHz that voice takes. Finally, it is possible to use two separate time slices (TS1 and TS2) to share one frequency between two separate transmissions. So in the same bandwidth as one analog transmission, you can squeeze 4 (A, B, C, D) digital transmissions.

One Continuous Xmission

TS1

TS2

TS1

TS2

TS1

TS2

TS1

TS2

1 Analog Transmission (12.5 kHz)

A

B

A

B

A

B

A

B

6.5 kHz

C

D

C

D

C

D

C

D

6.5 kHz

Now to make this work, the radio needs to know some specific things to set up a transmission.

Time Slots

First, it needs to know which of the two time slots your conversation will use – both radios, yours and either another DMR (simplex) or the repeater need to agree. Because if you are on TS1 and they are on TS2, you won’t be able to communicate.

Color Codes

Color Codes are a lot like PL tones, they allow your radio to filter out transmissions you don’t want to hear. But, both ends have to agree on the same color code, or your buddy’s radio will filter out your call.

Talk Groups

Now, when you have all this digital data flying around, its kind of like email – you need to know the email address of the recipient. That’s where talk groups come in. Having set up the correct time slot, and agreed on the same color code gets the radios set up to be in sync. But, they also need to know how to address the data. So, you also agree on a talk group. Then everybody who is on the same talk group can hear and talk to each other.

Okay, with simplex operations, this isn’t that important. And if you are both on the same repeater, you could work around it. But once the data is digital, it opens a world of possibilities in terms of linking repeaters – even ones that are hundreds of miles apart. And to do that, everybody needs to agree on the same talk group.

For emergency communications this is a very powerful tool. Our group, Denver ARES, is part of a public safety team for the major interstate I-70. The East region stretches from Denver to the Kansas line – over 170 miles of road. Thanks to the wonderful people at Rocky Mountain Ham – we can use one talk group (Central) and have a conversation with ARES members at the other end of the state – and do it with HTs at each end.

“Okay, okay,” you might be thinking, “You’ve sold me – how do I get started with DMR?”

What do you need (and where to get it)?

It is pretty easy, actually. You only need 3 things:

  • A DMR ID that is programmed into your radio as your personal ‘address’
  • A DMR radio, and
  • A CodePlug – the configuration file that the radio uses to know what to do.

DMR ID

A Radio ID is a unique number assigned to you (and your callsign) by the RadioID.net team. It is kind of like a telephone number or IP address. Your Radio ID identifies you as a unique radio user on the various DMR networks and repeaters around the world. You need to have a radio ID to use a DMR radio.

To get your Radio ID, you need to register with RadioID.net and upload an official copy of your Amateur Radio Licence. For U.S. radio operators, that can be done by1:

  1. Log into FCC system at https://wireless2.fcc.gov/UlsE.
    1. The FRN and password are the same you use when applying for Vanity callsigns and address changes.
    2. If you don’t know your FRN number, go to FCC ULS License Search and search for your callsign. Your FRN will be listed in the column FRN.
  2. On the left side menu, click on ‘Download Electronic Authorizations’.
  3. On the new page, select your callsign and click on the button ‘ADD >’.
  4. On the bottom right of the page, click on the button ‘Download >’.
    1. Make sure your pop-up blocker is disable, otherwise you won’t be able to download the PDF for your license.
      5. You will be asked to save a PDF file. Save it and submit it to RadioID, Simply create your account at RadioID and upload the License.
  5. That’s it. You will receive an email, usually within 24 – 48 hours, with your unique Radio ID, which you can promptly program into your radio(s).
    1. Note: You only need one radio ID even if you have multiple radios.
    1. DMR Radio

      Okay, yeah – you are going to need a DMR radio. There are too many on the market for us to give you a good overview.

      But, keep in mind that in many cases Emergency Communications groups, like ARES, will maintain a cache of radios to be distributed in the case of a deployment. So check with your team to see what is available.

      CodePlug

      In many ways setting up a DMR radio is just like setting up an analog radio that is used to connect to repeaters. While Code Plug sounds like some odd programming process, it is really just a configuration file. It will generally have three sections:

      • A Contact list – which are the talk groups you want to use
      • Channel Information – this is just like setting up a repeater, frequencies, and offsets, but you need a few more things for a the DMR like the time slot and the color code and so forth
      • Zone information – this lets you organize the talk groups and channels into groups that can be arranged by purpose (EmComm, Personal, etc.) or geography (North, Mountains, Vacation house, etc.)

      While you can build a code plug starting with a blank sheet, more often you will start with an existing Code Plug, and modify it to fit your needs.

      For EmComm usage, it is important to have a common operating model. Since many EmComm groups have caches of DMR radios to be distributed during a deployment, they will be programmed with a standard code plug that meets the needs of the group and its partner agencies.

      So, get the code plug approved by your group, or that is distributed for a specific emergency response.

      Operating procedures

      With an analog radio pressing the PTT immediately keys the transmitter and you’re ready to go. Not so on a DMR radio. When the PTT is pressed, a signal is sent to the repeater which checks to see if the Time Slot is available. If it is, a data stream is sent back to the radio giving you the All Clear, usually generating a beep tone. This occurs in just under a second.
      It is highly recommend that the BCLO (Busy Channel Lock Out) function is enabled. This prevents a station from transmitting on a Time Slot if it is currently active. Another indicator that the TG is in use is an activity light on the handheld. If the LED is lit, the Time Slot is in use.

      Busy Repeater Channel / Time Slot

      You may see the Channel Busy indicator lit, but not hearing a conversation. This is caused by someone activating or using a repeater Talkgroup other than the one you are monitoring.

      Digital Monitor

      Your DMR radio may have a ‘programmable key’ function labeled Digi Monitor or Promiscuous mode. This open allows you to monitor all activity on one or both time slots regardless of the Talk Group in use. This is a monitoring function only.

      General Rules:

      • 3 second pause before PTT
        • This allows for network latency as well as a courtesy pause for those wanting to enter the conversation.
      • 1 second pause after PTT
        • This is required for your radio to sync with the repeater and network.
        • You will get the Go Ahead signal if the repeater is clear.
      • Time Slot in use
        • This is usually shown by an indicator light or a time slot busy tone on your radio.
      • Talkgroup in use
        • You may not immediately hear an active Talkgroup. When switching to a different TG, your radio may need to sync to a conversation already in progress.
      • Announcing your presence
        • Announce both your Call Sign and Talkgroup. This will allow someone who is scanning to identify your Talkgroup so they can answer your call

1These instruction are adapted from the ones provided by DMR For Dummies: https://www.dmrfordummies.com/dmr-radio-id/

EmComm 101 – What is EmComm?

Basic EmComm

EmComm, or Emergency Communications is the practice of providing communication services during emergency response, especially in situations where traditional communication modes may not be available.

Overnight operations at a field station.

The primary role of ARES is to support the emergency management community (responders, relief and recovery agencies) with communications during times of emergency and disaster when normal communications are unavailable or overwhelmed.

We are communicators not first responders. If you arrive at the scene of an emergency just as the sirens are quieting, check in, keep your mouth shut, and get out of the way until you get an assignment! We do not provide first aid, transport victims, provide traffic control or any other function normally provided by public service agencies, nor are we running the show. We DO provide communication when public service systems are overloaded. We do not “self deploy.” We deploy when a partner agency requests our services.

Many hams think of ARES as a simple extension of the “talk time” in the hobby. This is not true. ARES are organizations that continually need more trained operators that are willing to learn to communicate rather than just talk. Do you have the time and the drive to do it well?

The goal is to provide trained operators that have learned to communicate accurately, clearly, and concisely in a timely fashion regardless of the obstacles in the event.

A brief history of Amateur Radio and Emergencies

“At 24 years of age on 14th of April 1912 Artie [Moore] received the faint signal of a ship in distress. The signal read: ‘CQD SOS 11.50pm from MGY we have struck an iceberg sinking fast come to our assistance position lat 41.46 north Lon 50.14 west MGY’. This was the distress call of the unsinkable Titanic! The call continued: ‘Sinking we are putting passengers off in small boats weather clear’.”

Newspaper Photo of the Titanic

The Titanic

This was one of the earliest documented events where an amateur radio operator became part of an emergency response. It wasn’t going to be the last. One direct result of the accident and the participation by ‘hams’ was the United States’ “Radio Act of 1912,” which, among other things, formalized the Amateur Radio Service. Part of the mission is to provide a pool of experts that can be drawn upon to provide backup communications during emergencies.

This led in turn, to the founding of the American Radio Relay League (ARRL), a ham radio member-society in 1914. As the ARRL grew, and the role of hams in providing communications grew with it, the ARRL established the Amateur Radio Emergency Service (ARES) in 1935. This standby radio service consists of “licensed amateur radio operators who have voluntarily registered their qualifications and equipment with their local ARES leadership for communications duty in the public service when disaster strikes.”

That tradition of Hams responding when asked to help is a core aspect of the value of ham radio to the community, and it shows up over and over again. During World War 2, the government shut down amateur radio across the country over concerns about the Axis powers using radio for espionage and sabotage. Hams went to war, and hams went to work designing and building new equipment and training radio operators for the military. On August 21, 1945 the FCC suspended the ban on amateur radio operations and the Hams shifted back to a new peace-time normal. But while the war had ended, emergencies did not.

On 9/11 the local ARES groups were activated within 5 minutes of the World Trade Center attacks, and hams are critical for emergency response during hurricanes and floods. During the category 5 storm Katrina event, more than one thousand ARES volunteers assisted in the aftermath and provided communications for the American Red Cross, The Salvation Army, and other individuals related to the relief effort. After Katrina, Hancock County, Mississippi, had lost all contact with the outside world, except through ARES operators who served as 911 dispatchers and message relayers.

ARES has deployed for a variety of other emergencies and disasters, including the 2003 North America blackout. The blackout covered a wide geographical area of North America. In the United States its scope included Cleveland, Detroit, and New York City. Landline telephones and cell phone systems were overloaded and amateur’s ability to operate off the grid was put to the test. On Long Island in New York many pieces of health and welfare traffic were passed on VHF and HF nets. Because some television and radio stations had gone off the air amateurs helped fill the lack of information. This was not the first time that amateur radio operators assisted during a blackout in New York City. On a warm evening of July 13, 1977, lightning caused a power outage across the city and most of its suburbs. Radio operators started communication nets on simplex and on a repeater located in the Chrysler building.

Since the earliest days of amateur radio, hams have jumped in during emergencies. But as EmComm has evolved, being ready to ‘jump in’ isn’t good enough any more.

EmComm today – best practices

Just as amateur radio adapted to changing conditions and changing needs, modern Emergency Response has evolved. The days when emergencies were handled by an ad hoc group of volunteers are being replaced with organized teams of emergency responders trained to work together and to have a common understanding of the best practices and working vocabulary of modern emergency response. Starting in 2003 and updated in 2011, Emergency Response best practices are defined by NIMS:

The National Incident Management System (NIMS) and the five National Planning Frameworks (Prevention, Protection, Mitigation, Response, and Recovery) provide the process and structures for meeting these mandates. Together, these related efforts align Federal, State, territorial, local, tribal, private-sector, and nongovernmental preparedness, incident management, and emergency response plans into an effective and efficient national structure. –From G 0402 NIMS Overview for Senior Officials (Executives, Elected, and Appointed)

Volunteers from agencies such as the Red Cross, the Salvation Army, and others work side by side with local officials, FEMA responders and the National Guard when an emergency strikes – and Amateur Radio operators are right there as well. When hurricanes threaten the coast, the Amateur Radio Hurricane Watch net activates, and organized teams prepare to relay communications. When wildfires strike, ARES and AUXComm members who have completed specific wildfire communications training are dispatched to the fire camps to run comms. During blizzards, amateur radio operators set up stations in shelters to relay information about capacity and needs – after spending hours training.

Modern Emergency Operations Center, dozens of highly trained specialists working together to respond to an emergency.

A typical ARES member may have put in 20 – 30 hours of course work, including table top exercises where the other players are local county emergency managers, FEMA employees, Civil Air Patrol members – in short the same team that will be expected to be on the front lines during an emergency. Beyond the classroom training, there will be hours of field exercises every year, Simulated Emergency Tests, and formal exercises with the local emergency responders.

Why all this focus on training and practice?

Since ham radio is their hobby, many hams have decades of radio communications experience. Some may have professional broadcasting experience, and others may be current/former first responders. In standards that have arisen with the introduction of the National Incident Management System, ARES members may also:

  • Be registered emergency/disaster workers under state law;

  • Possess certificates for (sometimes many) FEMA training classes;

  • Have passed law enforcement background checks; and

  • May be engaged in other volunteer activities such as Search and Rescue (SAR) or Community Emergency Response Teams (CERT).

To implement the goals of NIMS, the Incident Command System (ICS) has evolved into a complete end-to-end process for managing emergency response. Backed by extensive training courses (mostly free) it enables a ham radio operator to become certified up to any level they wish to achieve. In the Colorado Section of ARES there are 4 courses that are recommended ICS 100, 200, 700, and 800. These give the ham an understanding of what is expected, how things are organized, and provides the common language to talk with other emergency responders, no matter what their area of expertise. In addition, the Amateur Radio Relay League (ARRL) offers EC-001 a free course available to both members and non-members covering Emergency Communications from start to finish.

A modern emergency response is a complex machine designed to save lives and protect property. Like any well oiled machine the parts that make it work need to be able to work together, to speak the same language, and to have the same ‘situational awareness.’ And that takes study and training to learn the drill and it takes practice to make sure the knowledge can be put to use. If you were to take a beautifully running engine, and just drop some gears into the middle of the machine – no matter how perfect those gears were, no matter how well machined they were – what would be the effect on the engine?

In an emergency hams have to be able to work as part of the machine. Regardless of how well-intentioned they are, regardless of how much they want to help, they need the skills and training and equipment to work as part of the emergency response team.

Equipment

“If I’m responding to an emergency to provide communications, what equipment do I need?”

This is a question that comes up a lot – and (like many questions in Emergency Response) the answer is “It depends.”

First, as we discussed above, you won’t be responding to an incident as an individual – you will be responding as part of your team. You will get a call, text message, or radio message assigning you to a role. The first item of equipment is the “Know before you go” sheet. This is where you record your assignment – what is your role, who are you reporting to, when and where are you expected to be?

From this, the equipment question can be answered. Maybe you are being told to report to the local Emergency Operations Center – that could mean you will arrive at a facility that is already set up with everything you need to get to work: Power, Transceivers, and Antennas all set up and ready to go. Or you could be told to meet up with a partner and be prepared to pick up, deliver, and set up a complete rapid deployment field station at an incident command post. In that case, if you don’t bring it with you, you don’t have it to use.

As a result much of EmComm focuses on your ‘go-kit’, or rather one of several go-kits. A go-kit should contain everything you need to complete the assignment – and radio equipment is only one part of that. We tend to break down the go-kits into kits based on mission duration and tasking. How long will you be out, and what is your job.

For example a common 12 hour go-kit, is something easy to grab, and has what you need.

In this example, the 12 hour deployment kit is packed into a messenger bag with a shoulder strap. It contains a number of component bags – most are watertight plastic zip-lock bags. The contents are arranged into like items:

  • Radio gear: often a simple HT with a good antenna, spare batteries, and a programming cheat sheet – you may not know frequencies and PL tones until you get on site.

  • Uniform: You are part of a team and have a role. You need to identify so people can recognize your role. Also, this would include high visibility vests and /or hats for safety.

  • First aid: No you are not a medic – but if you cut your finger changing a battery, do you really want to bleed all over the equipment?

A typical Go Kit packed into a messenger bag

The Messenger bag unpacked into its component bags

  • Personal Protection Equipment: this can include a mask, Nitrile gloves, work gloves, goggles, and also any personal medications you need to stay healthy.

  • Documents and Identification: This would include ID badges, training certificates, a copy of your amateur radio license. Remember, you could be deployed to a site where they don’t know who you are.

As you can see, radio gear is only one small part of the kit.

Extended deployment kits are more complex, but follow the same basic breakdown.

For more details about equipment, check out EmComm-Equipment – either the online post or the in-person presentation.

Protocols & Procedures

Okay, so – you are part of an EmComm team, you have received an assignment, you grabbed your go kit and you have your “Know before you go” sheet filled out. Now what?

One of the key features of modern Emergency Response is that you don’t want to make the situation worse, you want to make it better. Or more simply: “Don’t become part of the problem!” So, there are specific procedures that are followed to keep responders safe. One of the first is that once you have an assignment – the Incident Commander is responsible for you. So you are going to notify the response team that you are heading out, possibly by phone, more likely by checking in to a resource net. This is a directed net that tracks all the resources – and you are a resource.

Resource Net Control this is AD0ZM.
Go ahead ZM”
I am leaving home at 09:50 hours to report to the Arapahoe County Fairgrounds for assignment.”
Copy that, AD0ZM, what is your starting mileage reading?”
Odometer start is 137455 miles.”
Copy 137455 miles”
AD0ZM clear”
KD0TWC, 09:52 hours”

At this point you are ‘on the clock’ and part of the resource teams responsibility is to make sure you get home again. You may be assigned to show up at a staging area, or you may be directed straight to an assignment. Once you arrive at your destination, you again check in and let them know. The reason they want you mileage is that in many cases they get credit (or potential reimbursement) for travel expenses. In other cases, the total number of miles and hours from volunteers can become a significant line item in future funding.

“But,” you ask, “How would I know to check in to the resource net?”

Remember those hours and hours of course work, training, and simulated emergency tests? Much of what they cover are the protocols and procedures that you need to know if you are going to be part of Emergency Communications response.

While some of the training is on radio skills, you already know how to operate a radio. You need to learn how to operate a radio as part of an EmComm team.

For example, let’s talk about tactical call signs. You have your call sign – and it is like your name, it is part of your identity. You use it automatically, you may even have found yourself ‘signing off’ a telephone call with it, right?

But in an emergency, messages don’t necessarily go to a person – they go to a position. Think about it: in an emergency response that might span multiple days, the person in charge won’t be there for 36 hours straight. So messages don’t go to Carol Smith, they go to the Bennett Shelter Manager. This morning that was Carol Smith, But now it is Alex Atwood, and by tomorrow morning it may be Steve Brown.

The same holds for you as a radio operator. To assure speedy and accurate communications, you wouldn’t call into the net with your personal call sign, you would use your tactical call sign. It is much clearer for the net control station to hear “Net Control this is Bennett Shelter” rather than hearing “KC0XYZ, this is W9FRB”

First off, KC0XYZ may be sacked out after a 12 hour shift, so she is not even on the radio. Second, the poor net control station doesn’t have to find a piece of paper with the who is assigned where information to figure out that W9FRB is assigned to Bennett Shelter.

But what about the FCC requirement for identification?” you might ask.

The rule is “Tactical in, personal out.” So after you have completed your exchange with the Net Control Station, you are going to sign off with your personal call sign “W9FRB clear.”

  • Tactical in – so everybody knows what station is calling and what station is being called.

  • Personal out – so every one knows the ID of the radio operators involved.

EmComm has a number of standardized procedures and protocols layered on top of the FCC regulations and common radio practices that are designed to enable emergency responders to focus on the real issue – save lives and protect property. How do you learn these protocols and procedures? Join an emergency response team such as your local ARES group and train and practice.

Training and Practice

Operating a radio is just like any skill: there is a big difference between ‘knowing’ and ‘doing’. This is even more critical during an emergency where being able to do the right thing at the right time can save lives. The only way to get proficient and to stay proficient is to train and practice. So almost every EmComm group focuses of building skills and tuning them.

You may have breezed through your amateur radio exams, or you may have spent weeks, months, or longer to get ready to pass you license tests. In the same way that there are dozens of ham test training courses, there are lots of EmComm training courses as well. And, just as you can’t run a radio until you have passed the exams, most EmComm groups require that you pass exams about emergency response before you can respond to an emergency.

Fortunately, almost all the courses are free, and many of them are available on-line. These courses focus on the background and operations for modern emergency response and specifically the Incident Command System or ICS. ICS is the playbook for how to deal with emergencies from small incidents to large disasters. For example, every major hurricane response is run using ICS. ICS is also used as a great playbook for ‘planned emergencies.’ Large events like the Super Bowl or New Year’s Eve in Times Square are run using ICS.

So, if you want to get an idea of what emergency response is like, take a course (I’d recommend ICS-200 Basic Incident Command System for Incident Response)

This is typically a required course for anyone in an EmComm Group. It assures that whether you are working with your own team or a radio operator from the Salvation Army SATERN team – you are both speaking the same language.

Beyond the course work, EmComm groups focus on skills and proficiency. What does that mean? Well, it means we get to play radio a lot.

A montage of images from the Denver ARES Power Systems Training, Hosted by Denver Water. It includes images of people starting generators, working with Solar panels, attending classroom discussions and building power cables.

Combined classroom and hands on training on power systems used for amateur radio, specifically Emergency Communications.

Our group – Denver ARES – typically runs 8 to 12 hands-on training classes every year, and does 5 to 7 events where we put that training into practice. These could be Simulated Emergency Tests, where we work with our partner agencies, like the Denver Office of Emergency Management, to set up a simulation of a real world emergency – a major blizzard like the 2019 ‘Bomb Cyclone’ shutting down the roads and taking out the electrical power, or a flood event like the Front Range and Eastern Colorado saw in 2013. We treat it like a real emergency, taking over specific repeaters to establish communications, running field and base stations off of emergency power, deploying radio operators to warming shelters or evacuation locations and setting up field radio stations. We practice the exact skills we would need for a real emergency, and then go out for a party afterwards.

Here in Colorado we also deal with severe weather. The National Weather Service ‘SKYWARN’ program leverages the mobile aspects of amateur radio.

A Skywarn Spotter reporting weather conditions via Amateur Radio

In many counties members of the local EmComm group are deployed as weather spotters, tasked with the job of reporting to a specific location and reporting on weather. These storm spotters report directly via radio to a net control station, directly to the county EOC, or relayed into the NWS office in Boulder to enable the forecasters to make more accurate predictions and issue precise severe storm or tornado warnings.

This is NOT ‘storm chasing’! As a member of an EmComm group you are tasked with a specific job to do, assigned a specific location to do it from, and need to follow a specific set of protocols for how to do it.

Every group does things a little differently, and practices different skills, based on the types of emergencies they expect to have to respond to. But, every organization practices.

Organizations

There are a number of organizations that provide emergency communications. Some simply provide EmComm services for partner agencies, some combine their primary mission with internal communications teams. Most are volunteer organizations.

Amateur Radio Emergency Services

The Amateur Radio Emergency Service® (ARES) consists of licensed amateurs who have voluntarily registered their qualifications and equipment, with their local ARES leadership, for communications duty in the public service when disaster strikes.

Every licensed amateur, regardless of membership in ARRL or any other local or national organization is eligible to apply for membership in ARES. Training may be required or desired to participate fully in ARES. Because ARES is an Amateur Radio program, only licensed radio amateurs are eligible for membership. The possession of emergency-powered equipment is desirable, but is not a requirement for membership.

American Red Cross

The American Red Cross provides two layers of emergency communications: first they maintain a number of licenses on commercial frequencies, and stockpile equipment for distribution to their response teams.

Second, they are part of a national Memorandum of Understanding with the American Radio Relay League which calls out (in part):

Whenever there is a disaster requiring the use of amateur radio communications resources and/or facilities, the local Red Cross region or chapter may request the assistance of the local ARES organization responsible for the jurisdiction of the scene of the disaster. This assistance may include:
• alert and mobilization of ARRL ARES® personnel in accordance with a prearranged plan;
• establishment and maintenance of fixed, mobile, and portable station emergency communication facilities for local radio coverage;
• point-to-point contact between Red Cross personnel and locations;
• the maintenance of the continuity of communications for the duration of the emergency period until normal communications channels are substantially restored, or until radio communications are no longer necessary in support of the response to the disaster

National Traffic System

The ARRL National Traffic System (NTS) is a well-organized system for routing formal written message traffic (radiograms) from any point in the United States to any other. Messages are relayed from one ham to the next, using a variety of modes such as voice, Morse code, radio teletype, or other digital radio modes. The NTS has its origins in the earliest days of radio as is indicated by the name, “American Radio Relay League” itself.

In times of emergency, radiograms may be used to communicate information critical to saving lives or property or to inquire or learn about the health or welfare of a disaster victim. During these times, NTS works in concert with the Amateur Radio Emergency Service (ARES) and other emergency and disaster relief organizations.

However, the NTS does not operate only during disasters. It operates day in and out 7 days a week, 365 days a year and is used by thousands of people, hams and non-hams alike, to send and receive brief greeting messages (happy birthday, congratulations on the arrival of a new baby, hope you feel better, etc.) as long as they are of a personal, non-commercial nature (as defined in the FCC rules).

Subject to international treaties governing “third party” messages, many foreign countries also allow their hams to exchange radiograms with US hams.

Salvation Army Team Emergency Radio Network

Since 1988, amateur “ham” radio operator volunteers have had a remarkable impact on the world in times of disaster thanks to SATERN (Salvation Army Team Emergency Radio Network). These trained men and women often are the only link to the outside world during disasters when cell phones towers are down, land lines are damaged and electrical power is out.

SKYWARN®

To obtain critical weather information, the National Weather Service (NWS) established SKYWARN® with partner organizations. SKYWARN® is a volunteer program with between 350,000 and 400,000 trained severe weather spotters. These volunteers help keep their local communities safe by providing timely and accurate reports of severe weather to the National Weather Service.

Although SKYWARN® spotters provide essential information for all types of weather hazards, the focus is reporting on severe local thunderstorms. In an average year, the United States experiences more than 10,000 severe thunderstorms, 5,000 floods and more than 1,000 tornadoes.

While not strictly an ham radio group local communities often work with trained SKYWARN spotters who rely an ham radio to communicate. During severe weather it is not uncommon for the traditional communications infrastructure to become overloaded, or to be out of action. Since amateur radio can operate without any external infrastructure, it can be ideal for relaying storm information.

Where to learn more

Denver ARES: http://DenverARES.org

Colorado ARES: http://ColoradoAres.org

American Red Cross: https://www.redcross.org/local/colorado.html

Salvation Army: https://westernusa.salvationarmy.org/intermountain_us_west/colorado/

National Traffic System: http://www.arrl.org/nts

ARES Manual: http://www.arrl.org/files/file/Public%20Service/ARES/ARESmanual2015.pdf

ARES TaskBook: http://www.arrl.org/files/file/Public%20Service/ARES/ARESmanual2015.pdf

ARRL EC-001 Course: http://www.arrl.org/online-course-catalog

Simply put, amateur radio emergency communications offers a very rich, challenging and rewarding environment to apply amateur radio knowledge and skills in unique situations where no one else has an available solution. Amateur radio operators that have honed their knowledge and skills have truly earned the right to be called emergency communicators.

The long path needed to deliver power to your house from the fuel needed at the power station to the substation in your area, to the transmission lines to your house, and to the socket in your wall.

Power Systems

Power Systems – Introduction

We can think of a functioning amateur radio ‘station’ as a tripod – the three legs are Power, Transceiver, and Antenna. If any of these are missing or out of whack, the tripod falls over, and the ‘station’ is inoperable or very inefficient.

The Power leg of the Ham radio station tripod

Power is one of the three critical legs that support your ham radio station.

In this blog, we will focus on the Power System portion of the tripod, what it does, how does it do it, and how can it go wrong. In some ways the Power System is unique. The Transceiver and Antenna components are under your control – you can build or buy whatever antenna you want, and mount it in what ever manner you choose (okay, subject to local ordinances and covenants); you can buy or build whatever radio system you want (subject to federal regulations, and your bank account). But often your power system will depend on an amazingly complex infrastructure – one that you have little or no control over. With that in mind – let’s get started!

What does a Power System do anyway?

The function of a power system is to deliver usable energy to the transceiver. This energy is then modulated to contain a signal on a specific radio frequency, and delivered to the feed line and the antenna. On the receive side, it provides the power to enable the radio to demodulate a received signal, and present the result as audio to the operator. Since it is the starting point for the radio’s function it is a key component of the Radio Station tripod.

So what can go wrong?

Well, of course the simplest thing that can go wrong is that the power simply isn’t there. Let’s begin by looking at three common ways of delivering power to the station, and examine their strengths and weaknesses. The three we will examine are: ‘shore’ power provided by the electrical grid, generator supplied power, and battery power (and its recharging components).

‘Shore’ Power

Power provided by the grid is both the most convenient and the riskiest source of power for your radio station. It is convenient because all you have to do is plug your power supply into the wall socket – everything else is taken care of by other people. It is the riskiest because everything else is taken care of by other people; and there is a lot of other stuff to take care of.

The long path needed to deliver power to your house from the fuel needed at the power station to the substation in your area, to the transmission lines to your house, and to the socket in your wall.

What a long strange trip it’s been.

Lets take a look at what is needed to deliver the power to the socket in your wall.

  1. The power supply that converts the AC from the wall into the correct DC voltage for your radio needs to be operational – this may be built into your radio, or it may be a separate component;
  2. The house wiring needs to be correct and intact;
  3. The line from your house to the street needs to be functional;
  4. The transmission lines and transformers from the substation need to be intact;
  5. The substation needs to be operational;
  6. The distribution lines from the power plant to the substation need to be intact;
  7. The generators in the power plant need to be operational;
  8. The power plant needs to have fuel (coal, natural gas, nuclear, wind, solar); and
  9. The surrounding power networks need to be ‘in sync’

All of these have to be working in concert to enable you to power up your rig. Since ARES focuses on emergency communications, we need to look at what can go wrong.

You could have a local problem: your power supply goes bad, taking out #1, or a tree is blown down in your yard taking out #2 or #3.

Image of the smoke plume from a failed electrical substation at Harrison St in Denver, CO.

When a substation goes, the power can be out for an extended period

A neighborhood problem: A truck plows into a power pole, a transformer blows during severe weather, or your local sub-station blows up taking out #4 or #5.

A regional problem: An earthquake, hurricane, or ice storm results in damage to the distribution lines (#6) or the power station (#7)

A national / global problem: Disasters, labor unrest or transportation problems block fuel delivery, or a nearby power grid becomes unstable forcing a shutdown in adjacent grids, taking out #8 or #9.

Wow, when you look at it this way – it’s amazing that we have reliable electrical power at all! So, what’s your backup plan?

Generator Power

A generator powering the House

Generator make you more self-sufficient. Kind of.

Probably the most common solution is to have a standby generator. This approach is used by most critical facilities such as hospitals, commercial radio and TV stations, emergency operations centers, etc., and by many home owners. Whole house generators are available as are smaller limited use generators feeding a subset of the home perhaps only providing power to the furnace and the refrigerator, and some lights. Of course for radio operators that limited use will include the ham shack 🙂 So with this solution we cut away a lot of the complexity of the power distribution system:

1) The power supply that converts the AC from the wall into the correct DC voltage for your radio needs to be operational (this may be built into your radio, or it may be a separate component)
2) The house wiring needs to be correct and intact;
7) The generators in the (your) power plant need to be operational;
8) The power plant (generator) needs to have fuel (gasoline, natural gas, propane)

Clearly a lot simpler, so less can go wrong. Assuming you can disconnect your home from the power lines in the back yard, you can eliminate #9, and you can almost ignore any neighborhood, regional, or national problems (for a while). You can get around the tree falling down issue by running dedicated lines (extension cords) directly to the equipment you want to run – if you planned ahead.

But this has costs. First there is the cost of the generator and installation – a whole house generator can run into the tens of thousands of dollars – and even a small standalone generator can run you several hundred bucks, and that’s just the monetary costs. You also need to maintain the generator and test it regularly, if it fails you are out of luck (#7). You are still dependent on fuel (#8). This can become problematic in the case of regional disasters where the gas stations may be unable to pump gas (if it is available) and refilling propane tanks may be impossible.

Battery Powered Field Station, a large Battery on the ground with power leads going to a radio on a portable table

The simplest possible power system, a battery. Taken at our Field Station setup exercise. (credit: lgunderson, AE0QN)

Let’s see if we can reduce this even more. Let’s start with a battery – one that supplies the DC voltage needed by the transceiver. That eliminates #1. Since we aren’t using the house wiring at all, #2 is covered. There is no generator so #7 is gone. That leaves only #8 – since a battery is only a storage system, how are we going to recharge it? What fuel can we use?

We can recharge it with a generator or a car (that brings #7 back into the list) but then we will need to ‘recharge’ the generator with some fuel source. Alternatively, we go green. Solar panels and / or wind generators can easily provide the ‘fuel’ for the battery. Because even a small home wind generator requires some form of tower – which could be damaged by that pesky tree that keeps falling over, let’s settle on a simple, portable solar panel set. Pull it out, set it up, plug it in, and wait for dawn. Hopefully you sized your battery to handle the radio traffic overnight, and sized your solar panels to both recharge the battery and provide power for radio operations during the day. Factor in that not every day is a beautiful sunny experience, so add some extra watt-hours for cloudy days. Not a bad solution for the delivery of power, but there is more that just the quantity of energy to think about.

What else can be a problem?

There are two other aspects that arise when you are your own power company – you become responsible for both the quality of the power and you are responsible for keeping things running.

Power Quality

Your transceiver is a very sensitive piece of equipment, and it can be thrown off by a number of things – including your choice of power system. The problems generally come down to two aspects: line noise and radio frequency interference (RFI).

Starting at the simplest side, a battery provides high quality energy. While it lasts, it delivers pure DC voltage with no ripples, pops, or noise.

A stable DC trace on an oscilloscope - a flat line across the screen.

Batteries and high quality regulated power supplies give your radio smooth stable power.

We need to recharge it and the recharge system can be noisy. Note: if you are using ‘smart batteries’ they add electronics to control the discharge voltage and so they can be noisy even when discharging. Some of the noise can be on the line – as the charge controller adjusts charging rates and voltages. These can impact the transmission side of your radio, potentially causing drop outs and adding noise to your outgoing transmission. These controllers can also cause RFI – pops, sizzles, and hums on the radio frequencies. This won’t impact your transmissions, but it can cause havoc on the receive side of things.

If you add a generator into the mix, the same problems are increased. Generators can be incredibly noisy on the RF side – so keep it as far away from your antenna as is practical. They can also provide ‘dirty’ AC line power.

The power companies, bless their hearts, spend literally hundreds of million of dollars to provide as close to pure sinusoidal AC to your house as possible. And your radio power supply depends on that beautifully smooth wave to provide clean DC to your radio.

Side by Side oscilloscope traces, one with smmoth sine wave, one noisy

The quality of the AC power supplied by the power lines or generator can affect your stations performance.

The backyard generator from the local big box store may not do the same. It often provides clunky square-wave like profiles, with hums, spikes and drop-outs. This doesn’t matter to your refrigerator, but is not good for your radio or your radio power supply. In addition, with all those moving parts (stator rings, whirling magnets, and so forth) they can actually generate more RF noise than your transmitter. So, if you go the generator path – check reviews by radio operators before you sink cash into a noise farm.

Moving up to shore power – things get better and worse. As I said above, the power companies want to deliver clean power to your house, and they generally do. But there are a lot of parts to the delivery chain. Substations and transformers can inject noise into the line – and even more into the RF spectrum. There are lots of stories and techniques for hunting down RFI in the power grid, and, once it is brought to their attention, the companies are pretty good about fixing the problems. But if we are talking about an emergency situation – all bets are off. Not only can damaged grid components generate tons of noise, but during the recovery the focus is on getting any kind of power to the customers, they will worry about clean later. Again, the more complex the system, the more parts are out of your control, but you do get a lot of convenience from just walking into the radio shack and pressing the power button on your rig.

Safety and Maintenance

You are your own safety officer!  When you are delivering power you have to wear a lot of hats.

Generator Safety and Maintenance

If you are delivering 120V AC from a generator – you might be in for a shock – literally.  Shock hazards, whether from a ratty old extension cord of questionable integrity, or due to badly engineered connections are a real risk.  Emergency generator power during storms adds in the risk of water shorting out your system. And remember – generators get hot, and they emit potentially poisonous gasses. So make sure that you place the generator on a level, non-flammable surface that is clear from any nearby fuel sources (gasoline, dried grass, piles of newspaper, you get the idea) and do not operate a generator inside, neither your house or the garage.  For generators, maintenance items include making sure you have fresh fuel (either gas or propane on site), the oil has been changed according to the manufacturer’s schedule, the generator has been tested, you know how long it will run under what conditions, etc. And test it on a regular schedule – the last thing you want is to confidently run out to fire up the genny and have it not start.

Battery Issues

First, remember that a battery is an energy storage device. There is a lot of chemical energy in there. Remember all those stories of batteries exploding?  https://www.thebatterystore.com.sg/wp-content/uploads/2018/05/carbatteryreplacement-singapore-624x468.jpgSo these things also take care and feeding.  Storing them appropriately is important for safety.

They can emit explosive gasses when charging so think through when and where you plan to charge them, the back of the closet in the kid’s room may not be a good choice, neither is next to the water heater. You will need to make sure there is a good charge on the batteries – notice, I did not say keep them full.

Batteries have a lifespan – ranging from a few hundred charge / discharge cycles to a lifespan measured in years. But eventually they die – you don’t want that to happen on the day you need the battery.

Many batteries have a maximum lifespan when they are kept around 80% full, not continually topped off.     Depending on the battery type, they will have an effective lower discharge limit as well. Factor this in when sizing your battery. A 1000 W-Hr battery may only give you an effective 500 W-Hrs for normal use, or 750 if you are willing to damage the battery. Many batteries prefer to be discharged before they are recharged – follow the manufacturer’s guideline’s and build a maintenance schedule for you emergency power. Then remember to follow your schedule.  Plan your work, then work your plan.

Wrapping Up

So that wraps up our tour of the Power System leg of the radio station tripod. We looked at sources of power, we looked at the delivery paths. We looked at what is needed to get AC to your ham shack, and some of the many, many things that can interrupt that flow. We did a quick dive into simplifying the needed infrastructure going from generators to renewable energy sources to pure battery power. Then we did a quick look at the quality of the power, since that also contributes to the operation of your radio station. Next we looked at some of the causes of both line noise and RFI, and made some suggestions about what can be done to reduce that noise. Finally, emergency power requires that you take on the job of the power company in many ways – importantly you are responsible for safety and maintenance of your emergency power system.

Remember to check out the other two legs of your Ham radio station tripod:

For some additional info on Power systems for Amateur Radio – check out this video by Dave Casler:

Antenna Basics

Antenna as part of the radio system

by Jim Gunderson, AD0ZM

We can think of a functioning amateur radio ‘station’ as a tripod – the three legs are Power, Transceiver, and Antenna. If any of these are missing or out of whack, the tripod falls over, and the ‘station’ is inoperable or very inefficient.

A tripod with legs labeld antenna. Power, and transceiver. The antennal leg is bolded.In this blog, we will focus on the antenna portion of the tripod, what it does, how does it do it, and how can it go wrong. Now don’t worry – I’m not going to fill the rest of the blog with equations, curl operations, or any calculus. We will talk about the physics, but more by way of metaphors. Our focus is on Amateur Radio for Emergency Communications (EmComm), and you are not going to be calculating any derivatives in the field. So, let’s get started!

What does an antenna do anyway?

Essentially, an antenna is a transducer – it accepts energy in one form and changes it into energy in another form. Specifically, it takes alternating current electrical energy in and spits electromagnetic waves out – or the other way around, it can take electromagnetic waves in and spit alternating current electricity out (this makes it a bidirectional transducer). That’s it, that is all it does. “But Jim, that sounds like any old piece of wire is an antenna,” you say. Yep – it is! But there is one key thing: an antenna is a passive element (which makes it a passive bidirectional transducer) – it doesn’t add any energy into the system, but it can be really inefficient and waste a lot of energy by turning it into heat. That heat doesn’t get the message out.

Everything about antenna design, construction and use comes down to two things – make the antenna as efficient as possible to maximize the energy transfer, and make the energy go where you want it to go. This latter point is important. A perfect ‘isotropic’ antenna sends the radio waves out in all directions equally, think about the sun or a light bulb. But, you don’t want to talk or listen in all directions. You want to hit that repeater on top of the building downtown a mile due south of you, or send a message to the Emergency Operations Center which is 15 miles to the north-west.

We know that an antenna can’t add any energy to the radio signal – but it sure can change the shape of the radiation pattern, for better (good) or for worse (not good). So the size, position, orientation, and height above ground all affect that radiation pattern, as do nearby objects, buildings, and terrain. These all change how the electrical energy is sent (or received) by the antenna.

In this post we will focus on the resonance of the antenna and a later post will look at the ways to change the radiation pattern.

How does an antenna do this wonderful thing?

We agreed that we would skip the equations, so we are going to explain this in words. By definition, it won’t be a precise, nor will it be as accurate, but it will get the message across, I hope. We will start with the transmission side of the transducer, what happens when you push the Push To Talk button? Through the engineering inside your radio (whether it is a little HT or a huge $10,000 rig) the sound of your voice is changed into alternating electrical current coming out the antenna connection on the radio. That signal arrives at the antenna.

The antenna is just a conductor, and so it conducts the current. Since it is alternating current it flows into the antenna for half a cycle, and flows back out during the other half. You can think of it like a wave sloshing in a bathtub, back and forth, back and forth. You might think it would just keep doing this forever, but we have a funny old universe.

It turns out that when an electrical current flows in a conductor, it causes a magnetic field to form, it transfers some of the electrical energy into the magnetic field energy. Well, that’s not so bad is it? The energy is still all there, just in a different form. But we have alternating current, so after half a cycle the current flow reverses, and the magnetic field begins to collapse. So what happens to the energy, you ask? Well, some really smart physicists figured out that when the magnetic field collapses it turns the energy into an electric field. So when we have alternating current in a conductor, we get a series of electrical and magnetic fields playing catch with all that energy, back and forth between alternating electrical and magnetic fields. And that process generates electromagnetic waves that take all that energy you pump in from the transmitter for a ride – traveling at the speed of light away from the antenna. You just made a radio transmission.

What affects its efficiency?

So, in a perfect world all the energy from your transmitter gets sent out as radio waves, whether it is 5 watts from an HT or 1500 watts from a massive power amp. Of course the world isn’t perfect – you get some losses because the conductor in your feed-line, and in the antenna itself are not perfect conductors. So you lose a little bit of energy every time the wave runs out to the end of the antenna and makes the round trip back. If the antenna is perfectly resonant, the energy gets transduced into EM waves completely on one trip – you have a standing wave with no reflected signal: and standing wave ratio (SWR) of 1.000000. That is a good thing. If the antenna is not resonant however, some of the energy gets reflected back along the antenna, and (like the bathtub wave) when it hits the other end (at the transmitter) it gets reflected once more out to the antenna, back and forth, back and forth.

But every trip causes a little more energy to be wasted by the resistance in the conductor, and turned into heat. So the worse your SWR – the less power you get out the antenna. It also can do bad things (think unpleasant smells, smoke, blown parts, trips to the radio store for new equipment) to the final stages in the transmitter, so keep the SWR low.

That’s not the end of the process, you need those radio waves to arrive at your intended target, so they have a long trip to make. Okay, not really long for electromagnetic waves – in an ideal environment (like free air or outer space) they will keep going forever. Think about looking up at the stars – if you manage to get a glimpse of the Andromeda galaxy those light waves have traveled 2.4 million light years and you can see them. But that’s a galaxy, you’ve got an HT, and that’s in free space, you are on a planet. And practically everything between you and your target will eat your radio transmission.

Trees, buildings, hills, almost anything will attenuate your signal to some degree. Water is bad. But you say, “Jim, I am not going to transmit through water!” Think about that HT clipped to your belt. On the one side the antenna is facing open air – perfect for sending a radio transmission to infinity and beyond. But, on the other side it is right next to you – and you are 70% water. Figure on about a 6 dB loss going through you – less than 1/4 of the power makes it out the other side. So think about which direction it is to the target, or better yet, pull the HT off your belt and raise it up to head level.

How can you make it better?

Well, it is not so much how you can make it better, as much as what can make it worse. Our reference antenna is a perfect 1/2 wave dipole with an SWR of 1.0, everything else compares to this. Of course it may not be possible to use a perfect antenna in some cases – imagine hiking through a festival with a Dipole on your back! You will most likely use a much smaller antenna.

The effect of using a smaller antenna is significant. Yes, the electrical characteristics can be adjusted so that the transceiver ‘sees’ it as a perfect 50 Ohm connection, but there are costs. Let’s look at the ‘rubber ducky’ that came with your HT. It is probably about 4 inches long and covered with a rubber coating.

The antenna is basically a coil of wire (an inductor) that is tuned for the center of the band. So on that frequency it is resonant, and has its lowest SWR. But there is another factor besides resonance. To be an ideal radiator – the length of the antenna comes into play. This is known as the aperture. The closer the aperture is to the wavelength the more efficient the radiation is. While electrically the rubber ducky is resonant, the length is far short of the ideal aperture, so it looses efficiency. That means more of the signal bounces back and forth – so that means a higher SWR, and that means more loss of radiated power.

There is also one other effect – the range of frequencies with good SWR gets smaller and smaller. So, with a 1/2 wave dipole you can get a low SWR across the entire band, the short antenna gives you a very narrow range where the SWR is good, and over the rest of the band it can be really high.

So, to summarize

The antenna is a key part of your radio system – it is the transducer that changes electrical signals into electromagnetic (radio) waves and vice versa.  In a perfect setup 100% of the electrical energy going in comes out as radio waves, but the world isn’t perfect.

SWR is one measure of the inefficiency of the antenna, the higher the SWR the more round trips the electrical energy makes, the greater the losses to heat.

As second aspect that can affect the efficiency is size – while shorter antennas can be made to ‘look like’ a perfect 50 Ohm antenna, the coupling between the antenna and the outside world (the aperture) is less than perfect. As a result the antenna has lower gain and is less efficient.

Choosing the right antenna for the mission is key and will be covered in a following post.

If you want to dig into more about the effects of size – check out this Wikipedia article: Rubber Ducky Antenna

Antennas are one part of the tripod that supports your Amateur Radio station, remember to check out the other two legs:

Can you operate without power?

Do you have some form of emergency power, whether battery, solar-charged batteries, generator?

This video is a sobering reminder of what can happen when the electric grid goes down–and a severe Coronal Mass Ejection (CME) or nuclear Electromagnetic Pulse (EMP) can take the grid down for days, weeks, even months. Published by the Electric Infrastructure Security Council: “Black Sky

In 1859, an extreme solar storm called the Carrington Event” caused sparks from telegraph keys, and fires. In 2012, a major solar storm of this magnitude missed earth by 9 days: more on solar CMEs.

Denver ARES Raises Awareness

The Denver office of Emergency Management sponsored a booth at the 2018 Fire Truck Muster event to raise awareness of both the CERT and ARES programs and their roles in supporting the Denver OEM during emergencies.

The booth was staffed by 4 members of Denver ARES (Linda Fried, Austin Pfenning, Louise and Jim Gunderson).

Denver ARES does this kind of outreach to keep the community informed and knowledgeable in advance of emergencies.

If you want to use your hobby to help your community, consider joining ARES in your area.

The Atlantic Magazine: ARES

Here’s a good article about how amateur radio operators use our hobby in public service, in the Amateur Radio Emergency Service (ARES), sponsored by the American Radio Relay League (ARRL).

The Atlantic Magazine: Hams Prepare

“Today the United States is home to more than 700,000 licensed amateur radio operators (including every member of my immediate family—I’m the only one without a ham-radio license, having failed the lowest-level technician test).

“Around 40,000 of them are part of the Amateur Radio Emergency Service (or ARES, pronounced like the god of war), a subset of the ARRL. There are branches all over the country, and ARES members are the hams that show up at the simulated disasters, ready to relay information wherever it needs to go. They helped out during disasters like Hurricanes Katrina and Sandy and the 9/11 terror attacks—they were the ones getting messages out even after the cellphone towers went down, overloaded by the family members of World Trade Center employees trying to reach their loved ones.” Read more…