Posts Tagged ‘emcomm’
The Future of Emcomm
Here comes Starlink!
I’ve been reading a number of reports from the areas affected by the two major hurricanes (Helene and Milton). The North Carolina experience is particularly interesting because people have experienced the loss of communication and electrical service for several weeks. I can imagine this same thing happening in other parts of the country, including my area.
There are two important technology disruptions showing up in North Carolina: satellite-based internet (Starlink) and mobile-phone-to-satellite (SMS) text messaging. Starlink is having a significant impact during this incident, while mobile phone satellite messaging is still emerging. Steve N8GNJ has some worthy thoughts on these topics in Zero Retires 173. Although I have served in many ARES/RACES deployments over the years, I don’t consider myself an expert in this area. I’d appreciate comments from Emcomm folks who have spent more time thinking about this.
Types of Emergency Communication
Most relevant emergency comms lump into 1) short-range comms (< 5 miles) between family, friends, and neighbors. 2) medium-range comms (50 miles) to obtain information and resources. 3) long-range comms (beyond 50 miles) to connect with distant family, friends, and resources.
- Short-Range Comms: This is the type of communication that is well served by mobile phones, except when the mobile networks are down. This is happening a lot in North Carolina. Lightly licensed VHF/UHF radios such as FRS and GMRS can be used to replace your mobile phone. Think: wanting to call your neighbor 3 miles away to see if they are OK or can provide something you need. (I have a few FRS/GMRS radios in my stash to share with neighbors. See TIDRadio TD-H3) VHF/UHF ham radio is, of course, even better for this, except the parties involved need to be licensed. (OK, you can operate unlicensed in a true emergency, but that has other issues. See The Talisman Radio.)
- Medium-Range Comms: This is a great fit for VHF/UHF ham radio using repeaters or highly-capable base stations. GMRS repeaters can also serve this need. These communications will typically be about situational awareness and resource availability in the surrounding area. For example, someone on the local ham repeater may know whether the highway is open to the place you want to drive.
- Long-Range Comms: Historically, this has been done by HF ham radio and a lot of emergency traffic is still handled this way. The shift that is happening is that setting up a Starlink earth station feeding a local WiFi network can help a lot of people in a very effective manner. Compare passing a formal piece of health-and-welfare traffic via ham radio to letting a non-licensed person simply get Wi-Fi access to their email or text messaging app. Hams are doing this, but many unlicensed techie folks have set up these systems and freely shared them with the public.
Mobile Satellite Messaging
Various providers now offer a basic text messaging capability using smartphones talking to satellites. Today, this capability is often limited to emergencies (“SOS”), and it is relatively slow. With time, this capability will certainly improve and basic satellite texting will be ubiquitous on smartphones. This will be great for checking in with distant friends and families, but it may not be that useful for Short Range and Medium Range comms. Someday, it might include voice comms, but in the near term, it is probably just text-based.
Evan K2EJT provides some useful tips based on his experience here in this video. However, he doesn’t address the Starlink capability.
Summary
While much of the public appreciates the usefulness of ham radio during emergencies, I am already hearing questions like “Doesn’t Starlink cover this need?” My view is that Starlink (and similar commercial sats) is very useful and will play an important emcomm role, but it does not cover all of the communication needs during incidents such as hurricanes, blizzards, wildfires, earthquakes, etc. Emcomm folks (ARES and RACES) will need to adapt their approach to take this into account.
Those are my thoughts. What do you think?
73 Bob K0NR
The post The Future of Emcomm appeared first on The KØNR Radio Site.
Vacuum Tubes – Electronics at Work: 1943 Educational Film
In the classic educational film titled “Electronics at Work,” produced by Westinghouse in 1943, viewers are introduced to the fascinating world of vacuum tubes. This film highlights the crucial role these devices played in both military and commercial sectors, including radio telecommunications, radar, and various industrial applications. The narrative suggests that vacuum tubes provided the United States with a significant advantage during World War II, particularly in enhancing communication and technology.
The Continuing Relevance of Vacuum Tubes
Despite advances in technology, vacuum tubes remain in use today for several applications, including:
– Transmitting radios
– Medical devices
– Audio amplification systems
– High-frequency applications
Understanding Vacuum Tubes
The film outlines the six basic functions of electronic tubes and illustrates how each type is employed in different industrial and military contexts.
[embedyt] https://www.youtube.com/watch?v=ZJ6rN7WEjbc[/embedyt]
Structure of a Vacuum Tube
A vacuum tube typically consists of two or more electrodes housed within a vacuum inside an airtight enclosure. Key features include:
– Electrode Types: Most vacuum tubes have glass envelopes, although some utilize ceramic or metal casings with insulating bases.
– Leads and Sockets: The electrodes connect to leads that pass through the envelope via an airtight seal. These leads often take the form of pins, allowing for easy replacement in a tube socket, as tubes were a common point of failure in electronic devices.
– Capacitive Design: Some tubes feature a top cap on the electrode to minimize interelectrode capacitance, enhancing high-frequency performance and maintaining safety by separating high voltages.
The Evolution of Vacuum Tubes
The earliest vacuum tubes emerged from incandescent light bulbs, which contained a heated filament sealed in an evacuated glass envelope. When heated, the filament releases electrons into the vacuum through a process known as thermionic emission.
– Electrode Functionality: A second electrode, known as the anode or plate, attracts these electrons if it holds a more positive voltage. This mechanism results in a flow of electrons from the filament (cathode) to the plate, creating an electric field due to the potential difference between them.
– Diode Function: A vacuum tube with two electrodes is termed a diode, which functions as a rectifier. Diodes allow current to flow in only one direction, converting alternating current (AC) into pulsating direct current (DC). This technology is widely used in DC power supplies and in demodulating amplitude-modulated (AM) radio signals.
Film Availability and Production Details
This film is available in the public domain under Creative Commons, and it can be accessed through the Library of Congress Prelinger Archives. The film has been edited and converted to HD quality for better viewing. Introductory and closing music is provided by Nero 10, with commercial use rights granted.
This film not only serves as an educational tool but also highlights the enduring legacy of vacuum tube technology in the realm of electronics, illustrating its significant contributions to both past and present technological advancements.
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Exploring Shortwave Radio Signals: A Peek into Non-Local Communications
Curious about what you can hear on shortwave ham radio? This video is a brief survey of the diverse world of communications on the shortwave spectrum. Expand your radio horizons and enhance your emergency communication preparedness by tuning in to the world of shortwave ham radio.
If you’ve started delving into radio communications beyond local stations and channels, like VHF and UHF, you’re in for a treat. Shortwave radio opens up a whole new realm of signals to explore, including emergency communications vital during natural disasters.
[embedyt] https://www.youtube.com/watch?v=pIVesUzNP2U[/embedyt]
Shortwave radio covers a range of radio frequencies from 3 kHz to 30 MHz. This spectrum is home to a diverse array of radio signals that cater to various communication needs, making it a hub of activity and connectivity.
Within these high frequencies, you can tune in to a multitude of transmissions, from transoceanic air traffic control communications to the chatter of ships navigating the vast seas. Imagine hearing the voices of fishermen, much like those on your favorite reality TV shows about high-seas fishing adventures, along with military communications and the vibrant world of amateur radio enthusiasts.
One of the remarkable features of high-frequency (HF) radio is its ability to propagate signals over long distances, transcending line-of-sight limitations. This means that HF radio enables communication between different regions and even continents, fostering connectivity across vast distances.
During times of crisis and natural disasters, shortwave frequencies become invaluable for emergency communications. When local infrastructure falters or is disrupted, shortwave radio serves as a vital lifeline, facilitating critical two-way communications in and out of disaster-stricken areas.
Explore the fascinating realm of shortwave radio, where distant voices blend with essential information, bridging gaps and connecting communities in times of need. Uncover the power of HF radio to transcend boundaries and provide lifelines when they are needed most.
In this video, I give you a glimpse of the voice and data transmissions I pick up on my high-frequency amateur radio transceiver (in this video, an Icom IC-7000). In later videos, I will dive deeper into specific types of HF communications, such as aeronautical trans-oceanic signals.
FRS3 For Colorado Backcountry
The Colorado Search and Rescue Association is promoting FRS (Family Radio Service) Channel 3 as “the default during backcountry search and rescue (backcountry SAR) emergencies.” FRS channel 3 is the same as GMRS (General Mobile Radio Service) channel 3. There is more GMRS info here. To keep things simple, no CTCSS (“privacy code”) is used…carrier squelch only. See the CSAR announcement here: FRS Radio Use for Backcountry.
For backcountry exploring, it is important to emphasize self-sufficiency and to avoid reliance on electronic gizmos that may fail. Avoiding an emergency situation is way better than having a device to call for help, which may be many hours away. See this article for a discussion of The Ten Essentials for Hiking.
Still, the FRS3 concept has merit. Many backcountry hikers already carry FRS or GMRS radios, so designating a preferred channel makes sense. My read on this is that randomly calling for help on FRS3 will not be very effective due to the limited range of FRS radios. However, it does not hurt to try. More likely, FRS3 can be used for local comms once Search and Rescue crews have been deployed and are within a few miles of the party in distress.
Ham radio operators may want to carry a handheld transceiver capable of transmitting on 462.6125 MHz. For emergency use only, of course.
73 Bob K0NR
The post FRS3 For Colorado Backcountry appeared first on The KØNR Radio Site.
New Book: Learning, Living, and Loving Morse Code…
There is a new book from a fellow Morse code amateur radio operator, Chris Rutkowski (NW6V), about “Learning, Living, and Loving Morse Code (in a Digital World).” NICE!
Title: “The CW Way of Life“
link: https://amzn.to/3Tm3KfD
Already, I think it rivals any other book on the topic, including “The Art and Skill of…,” or, “The Zen of…”
It is not, however, meant to replace, but to augment, what is available. But, it is a complete guide, including a “work book” section (nearly half of the book?) on how to improve your skill. Really good stuff, but I’m only in one day.
73 de NW7US dit dit
https://nw7us.us
..
Perfect Straight-Key Morse Code? Can It Be Made Without Machines?
How Much Does Emergency Power Cost?
Some folks are criticizing the ARRL for not modifying the Field Day rules in response to the Wuhan virus epidemic. Most of them are looking for a way to operate Field Day from home but still have a club score of some kind. I posted my thoughts here: Don’t Mess With The Field Day Rules.
The Field Day (FD) rules allow for a home station with commercial power to participate in FD as a Class D station. However, Class D stations cannot work other Class D stations for points. If the home station has emergency power (batteries, gasoline generator, etc.), then it is a Class E station that can work all FD stations for point credit.
Emergency Power: Too Difficult?
I’ve heard some hams argue that it is too difficult to set up emergency power for their home station. In many cases, the argument is actually that it is too expensive to do this. I can see this point if you run out and buy a name brand gasoline generator…a Honda EU1000i costs about $950.
This raises the question of what is the lowest-cost way to equip a home station for emergency power? Let’s consider the case of a typical 100W HF transceiver such as an IC-7300 or FT-991A. These radios require a 12 V power supply at 22 A maximum on transmit. Receive current is much lower, typically 1 to 2 A. Under FD rules, we don’t need to power our computer or other accessories from emergency power, just the radio. If we assume a 50% duty cycle, this class of radio consumes about (22+2)/2 = 12 A average current. (Yes, you could choose to operate QRP and really stretch the battery but let’s stay with the 100 W scenario.)
Get A Battery
So what is the cheapest way to get this done? Let’s take a look at using a deep-cycle battery. Walmart has an RV/Marine battery for $75, rated at 101 AH. Assuming 12 A of current, this battery would support about 8 hours of radio operating. This is going to be way short of the 24 hour operating period of FD but it might be enough to support a less intense operation. We could also do some things to stretch out the battery life, such as reducing our transmit power. Dropping to 50 W would roughly double the operating time to 16 hours, which should be enough for a single-operator station.
Of course, another option is to double the battery capacity by using two batteries. These amp-hour ratings on batteries are always a bit idealistic and our transmit duty cycle might be more than 50%. Let’s assume we buy two batteries to give extra margin and allow us to run 100W. We will also need a simple charger, which costs about $25. So there you have it, 2 x $75 plus $25 = $175 for a decent emergency power source. (If we decide to use only one battery, the cost drops to $100.)
Now $175 is a significant investment and only you can judge how well your ham radio budget can support this. For many people, this is affordable and the real question becomes is this how you want to spend my hard-earned cash.
This is my best shot at a low-cost emergency power source. Do you have a better idea?
73 Bob K0NR
The post How Much Does Emergency Power Cost? appeared first on The KØNR Radio Site.