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Thread: Intro to Radio Communications

  1. #41
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    Quote Originally Posted by faithmyeyes View Post
    A couple of additional comments -

    I want to clarify that my statement regarding ARES et al was not intended to be a blanket indictment of all amateur radio organizations. The largest ARES group in my area, for instance, focuses primarily on severe weather reporting and has an excellent relationship with the National Weather Service. They perform that function well, and only a few of them on the fringe get really rabid about things like FEMA certs and radio e-mail for the Red Cross. But things in some groups really get off in the weeds, and as QuietShootr said, many of the guys who are heavily into it aren't all that well-balanced. Some of them seem to feel like amateur radio is just waiting its turn to save the world, and that it's every operator's sacred and noble duty to be prepared for that day. By the way, who's bringing the beer?
    My ARES group does a lot of weather spotting, but it doesn't end there. We work directly for the county 911 and built the county's EMCOMM van for cost of materials. We roll it out whenever any county Public Safety agency requests it and even man the radios if the agency requesting it cannot. We've earned the respect of the Public Agencies we serve and don't tolerate the bozo element.

    The FEMA certs you mention are probably the IS100,200, 700 and 800 courses. The reason why it's being pushed is because it's being mandated gradually for everyone working an incident, it's mandatory for First Responders and is tied to FEMA funding. Besides, it's good training even for your own personal or family disaster planning.

    Unfortunately, the ARRL (the amateur radio equivalent of NRA) seems to be in the same boat of pushing for integration with government services and "served agencies." They've co-opted the "hero" angle (When All Else Fails... AMATEUR RADIO) and gone wrong-headed in an attempt to attract membership. So in general, the amateur radio "party line" about what disaster communication looks like is probably quite different that what most self-reliant preppers would find sensible.
    The problem with this is that the ARRL's Media campaign is factually correct: When the public safety and cell phone towers fall, usually it's the geeky guy with all the radios who can cobble together a few pieces of wire and is able to get messages out at least to the other geeky guys in the next town.

    Remember the Falklands war? How about the Grenada before we invaded? The only information anyone had about what was going on during both those crises was from ham radio operators on their respective islands. Same thing happened with Katrina. More than a few agencies who thought HF was a dead mode of communication were schooled during Katrina and it was ham radio that demonstrated the fact it still had use in disasters. I've read more than a few after-action reports from Rita and Katrina where it mentions those same screwball hams who set up in the field, on their own, made a big difference.



    There can be some value found in being involved with a local club, though. I've been involved several times when a club has been called on to provide communication support for a community effort like a bike race, marathon, or even an SCCA motorsport event. These events can give you a valuable opportunity to prove your equipment and operating practice in a "real-world" tactical communication scenario.
    +100


    Furthermore, if you can wade through the BS at some of the club meetings, you may find that the quiet older gentleman sitting against the wall is well worth getting to know. If it's communications or electronics you're interested in, some of those guys have truly been there and done that, with an amazing wealth of experience.

    So yeah, understand that the culture can be a little weird, but don't throw the baby out with the bathwater. You can be friendly, soak up some valuable tools and techniques, and quietly avoid the Kool-Aid table altogether. Then take home your new knowledge and make it work for you and yours.
    All I'm going to say is that the parallels between gunowners and hams is uncanny. Everything you've said about hams could generallay be said about the shooting community as a whole. Remember that.

    And now for something completely different:

    How useful CB is depends on where and when you are. If you're close to major trucking arteries, you'll get a lot of unwanted signal. Additionally, CB operates on a frequency that is capable at certain times of long-distance skywave propagation or "skip." I can remember having a CB walkie-talkie as a kid and not being able to find a clear channel for all the South American operators.

    Be wary of "peaked" or "tuned" CB transceivers, as they have often been modified in a way that makes their operation illegal. Yes, illegal operation is widespread on CB now that operator licenses are no longer required - but we want to be above reproach, don't we?

    In an area with less interference, you can communicate over a fairly impressive range with a perfectly legal CB - especially if you have transceivers capable of single-sideband (SSB) operation. SSB into elevated horizontal antennas will work even better. And nobody has to take a test or pay a license fee to run one.

    fme
    Last edited by jaholder; 09-26-09 at 01:32.

  2. #42
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    Stole this "Idiot's Guide" from Jim Rawles' website:

    "Amateur Radio for the Rest of Us, by Jim in Illinois

    In the modern world, there are few things as critical as the propagation of information. Anytime, day or night, we have access to news, weather, and interpersonal communications. When that information is
    unavailable whether due to a misplaced cell phone, internet disruption, or other factor, we begin to panic, feeling cut off and isolated.

    When disaster strikes, up to date information could be as vital to your survival as food, shelter, or a means to defend yourself.

    We can all make plans for our retreat and relocation, but without a means of contacting one another when the time comes, all we can do is wait and hope that everyone is on their way.

    What is amateur radio?
    Amateur radio, also known as ham radio, is a service designed for the purpose of intercommunication between individuals whether for casual chatting, emergency preparation, or in the event of an actual emergency. The FCC permits citizens that have proven proficiency in FCC rule and of reasonable technical ability to use this service. To do so, one must pass a written exam and register their information with the FCC to obtain a license. Transmitting on amateur radio bands without a license could subject a person to fines or even imprisonment. However, there is one caveat to this rule. During an emergency, when lives are at risk, anything goes.

    The phrase “anything goes” rarely has as much significance as it does in a TEOTWAWKI situation. Now, I am certainly not condoning the unlicensed use of amateur radio. But there may come a time that the only thing between you and rescue is a ham transceiver.
    As quoted in the FCC amateur radio rule book:

    §97.405 Station in distress.
    (a) No provision of these rules prevents the use by an amateur station in distress of any means at its disposal to attract attention, make known its condition and location, and obtain assistance.
    (b) No provision of these rules prevents the use by a station, in the exceptional circumstances described in paragraph (a), of any means of radio communications at its disposal to assist a station in distress.

    Note: With that said, I would still encourage anyone making any effort in preparation to seriously consider following the licensing procedure.

    Amateur radio signals are capable of traveling thousands of miles, or as short as tens of miles.
    There are many factors that will affect the distance your signal will travel.
    Some of them include:

    Transmit Frequency
    Just like with an AM/FM radio, there is a wide spread of radio frequencies that signals can be received on. Common allocations for amateur radio can be found anywhere from 3M MegaHertz (MHz) to well over 440MHz.

    Typically the lower frequencies, from 3-30MHz (High Frequency or HF) provide the greatest distance with the least amount of power. This is accomplished by natural phenomena called ‘propagation’, which will be explained later.

    VHF 30-300MHz (Very High Frequency) and UHF 300-3000MHz (Ultra High Frequency) offer a very high quality signal for ‘line of site’ distances up to about 50 miles. Police, fire, and private services rely on these frequencies due to the clarity and reliability of communications. FRS/GMRS (Family Radio Service) radios use 460MHz (UHF).

    Antenna
    In amateur radio, the most important factor is the antenna. An antenna can be as simple as a long piece of wire strung through a tree, or as large as an array of directional antennas hundreds of feet in the air. Just because it’s simple though, doesn’t mean it won’t work. I have talked to a ham in Portugal from my living room in Illinois using nothing more than a piece of wire looped around my ceiling fan.
    ‘Any’ antenna will work better than ‘no antenna’.

    Transmit Power
    Transmit power is measured in watts. While amateur radio has a limit of 1,500 Watts, most transceivers will only put out about 50-100 watts. Ideally, the more watts put out, the farther the signal will travel. You must also remember though, the more watts transmitted, the more power the radio consumes. This is something to keep in mind when battery power is in precious demand.
    It is generally a good practice to keep output power low when possible, and make up the difference with improvements in your antenna. I have talked to Japan on 5 watts from Illinois. Power isn’t everything.

    Propagation
    During the day, solar rays charge different layers of the atmosphere which create a reflective barrier for radio waves. As the sun fades for the day, so does our propagation.
    Higher frequencies require a higher amount of charged particles. Radio waves that do not bounce are simply absorbed or pass right through. During times of good propagation, it is possible to send very weak signals across the globe.
    We can, to an extent, control how far our signal will go by utilizing the three main types of propagation.

    Skywave (long skip)
    By utilizing an antenna that has a low take off angle, like a vertical antenna or high dipole (like your FM stereo comes with), our signals are directed at the horizon which will hit the atmosphere and bounce back to earth. (The earth is round, remember?)

    NVIS (Near Vertical Incidence Skywave)
    With a lower dipole antenna or tilted vertical antenna, we increase the angle of the radio waves. Therefore, the waves go up sharply and bounce down much closer.

    Groundwave (line of sight)
    Line of sight communications solely rely on the receiving station being within a straight line of the sending station. A walkie-talkie is a good example of this. Repeaters, which I will cover below, are often used to increase range of line of site radio equipment. Output power and antenna height greatly improve line-of-sight (LOS) communication.

    Setting up a station

    When determining what radio equipment will suit your needs, you must first decide on a few things.

    How far do I need to communicate?
    How portable will I need it to be?
    How much can I spend?
    VHF/UHF
    If you answered the first question with “less than 50 miles”, then you can easily set yourself up with a useable system for under $200. VHF and UHF transceivers are often called 2 meter and 70 centimeter radios, respectively. 2M and 70CM refer to the length of the actual radio wave. 2M operates around 145MHz and 70CM operates around 440MHz.

    Handhelds
    A handheld unit has the advantage of small size, internal battery pack, and built in antenna. On the other hand, the small size, internal battery pack, and built in antenna is a serious compromise regarding transmit and receive distance. Typical handhelds maximum power output is about 5 watts and the internal battery won’t last long at that power level. The functionality of a handheld unit relies on repeaters. Without a repeater, a handheld would be limited to about 10 miles or less.

    A repeater is a transceiver with a very high antenna that receives a signal on one frequency, and retransmits on another, usually at a much higher power. Through the use of repeaters, it is possible to work stations >100 miles away with a walkie-talkie. This may sound like fine business, but repeaters are privately owned and would likely be locked down by the owners, without power, or seized by the government, should society crumble.

    Mobiles
    Mobile units are designed to be mounted in a vehicle and are powered by 12 volts. Although an external antenna is required, this gives the user the flexibility to decide which antenna works best for them. Most mobile units can produce at least 50 watts and can be reduced to lower power as needed. A base or even portable station can be easily setup using a mobile radio, rechargeable 12 VDC battery, and an antenna placed as high as possible. With careful planning and experimenting, this system can be optimized to reach distances of 50 miles or more, creating an efficient point-to-point communication link.

    HF
    For nationwide communication, HF is going to be the winner hands down. HF radios are typically capable of more than 100 watts and under good conditions can talk coast to coast and across the ocean. The greater distance is attributed to propagation, as described earlier.
    The biggest stumbling block with HF radios is the cost. With a starting price of around $700, most folks will find it very hard to make room in their budget for this.
    Another consideration is the antenna. To work efficiently, an antenna should be at least ¼ wavelength long. Depending on the frequency, this could be anywhere between 10’ to well over 60’. But as stated before, any antenna is better than no antenna.

    Conclusion
    Undoubtedly, whether your plans are staying or relocating, reliable communications will be a must for you and your group. This article is written as a primer into amateur radio and to simplify what can seem to be an overwhelming step of preparedness. There are hundreds of volumes written on the subject, and I would encourage anyone serious about prepping to research further.

    I really can’t stress enough that you should take the time now to get licensed and work out any problems before they occur."


    Links:
    www.arrl.org Find testing locations and just about anything else ham-related.
    www.qrz.com Take online practice tests for amateur radio exams
    Last edited by Outlander Systems; 09-26-09 at 19:03.

  3. #43
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    @Landlord:Thanks for the info, and the thought-provoking post.

    I recently bought two Etón FR1000 Voicelink FR-1000 radios. They are portable but not pocket-sized. I plan to get the license to use it legally, though almost no one seems to do so. I also intend to find a few decent quality handhelds to go with them and include those in my go-bag. These units are pretty sturdy, and not the typical all-in-one device that breaks in a week.

    * 22 GMRS (General Mobile Radio System)/FRS (Family Radio System) channels
    * 121 privacy codes (38 CTCSS / 83 DCS)
    * AM/FM receiver
    * VOX (Voice operated transmission)
    * NOAA weather radio and NOAA weather alert
    * Siren and Flashlight
    * Can be powered from four different sources:
    o Rechargeable Ni-MH battery (built-in)
    o Dynamo crank alone
    o 4 “AA” batteries
    o AC Adapter (included)
    * Cell-phone charging jack


    Here's what the FCC has to say about range of different short-distance radio types:

    * FRS - range less than one mile
    * CB - range 1 to 5 miles
    * GMRS - range 5 to 25 miles

    This is, obviously, under ideal conditions, and with fairly high (>2watt for GMRS) power output . In hilly terrain, bad weather, and/or lower power conditions, the laws of physics take over. So fairly short distance, but probably good enough for most of my intended purposes.

    While I'm interested in HAM for longer distances, I don't think it is going to be right for me. The hardware, time, and licensure requirements are much greater, so it will have to be back-burnered until I take care of other priorities.
    Last edited by HiggsBoson; 09-26-09 at 21:31.

  4. #44
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    The hardware, time, and licensure requirements are much greater,

    You just think it is.


    Two weeks can get you your technician liscense and $500 can get you a good 2meter mobile and two good 2M HT's+an Antenna for the Mobile.

    http://www.gigaparts.com/store.php?a...ku=zys-ft-2800

    http://www.gigaparts.com/store.php?a...ku=ZYS-FT-270R

    Add about $70 for a good 1/2 wave mobile antenna. I like Larsen myself.

    You are still well under $500. This does not have to be an expensive hobby unless you make it one.
    My brother saw Deliverance and bought a Bow. I saw Deliverance and bought an AR-15.

  5. #45
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    Quote Originally Posted by st_judas View Post
    @Landlord:Thanks for the info, and the thought-provoking post.

    I recently bought two Etón FR1000 Voicelink FR-1000 radios. They are portable but not pocket-sized. I plan to get the license to use it legally, though almost no one seems to do so. I also intend to find a few decent quality handhelds to go with them and include those in my go-bag. These units are pretty sturdy, and not the typical all-in-one device that breaks in a week.

    * 22 GMRS (General Mobile Radio System)/FRS (Family Radio System) channels
    * 121 privacy codes (38 CTCSS / 83 DCS)
    * AM/FM receiver
    * VOX (Voice operated transmission)
    * NOAA weather radio and NOAA weather alert
    * Siren and Flashlight
    * Can be powered from four different sources:
    o Rechargeable Ni-MH battery (built-in)
    o Dynamo crank alone
    o 4 “AA” batteries
    o AC Adapter (included)
    * Cell-phone charging jack


    Here's what the FCC has to say about range of different short-distance radio types:

    * FRS - range less than one mile
    * CB - range 1 to 5 miles
    * GMRS - range 5 to 25 miles

    This is, obviously, under ideal conditions, and with fairly high (>2watt for GMRS) power output . In hilly terrain, bad weather, and/or lower power conditions, the laws of physics take over. So fairly short distance, but probably good enough for most of my intended purposes.

    While I'm interested in HAM for longer distances, I don't think it is going to be right for me. The hardware, time, and licensure requirements are much greater, so it will have to be back-burnered until I take care of other priorities.
    There's no way in hell you're going to get even 3 miles out of a GMRS handheld if you're talking to another handheld.


    In re ARES:
    Last edited by QuietShootr; 09-26-09 at 22:01.

  6. #46
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    I appreciate the additional info, HeavyMetal, and after spending more time in this thread and elsewhere, I do intend to move toward HAM when I have more time and money to invest, but I still think my point is valid. I have very little initial investment (in time or $$) and I am already using a system that works moderately well, albeit not in the longer distances I would prefer.

    Quote Originally Posted by QuietShootr View Post
    There's no way in hell you're going to get even 3 miles out of a GMRS handheld if you're talking to another handheld.
    Agreed and understood. Hence my comment about the laws of physics... I'm intending the handhelds only as supplementary to the larger units I already have. The higher-wattage units get more distance, especially with a larger antenna, and I have two of them for the two places with which I feel the need to communicate. I am also going to have handhelds to be rapidly portable in case I need to hoof it. Much like I did with firearms, in buying and learning a reliable pistol before I got into carbines, I am making comms purchases based on the time and $$ commitment I feel like I can make at the current time. Having GMRS today is better than planning to invest in HAM and not having anything in hand. Now that I have it, I can spend a few months researching HAM and learning about it. When I feel like I know enough to make an informed purchase that will meet my needs, only then will I take that step.

    As with every time I post in this wonderful forum, I mostly just learn how much I have yet to learn. This is why I'm in this thread, after all. To bounce ideas and to learn.
    Last edited by HiggsBoson; 09-26-09 at 23:35.

  7. #47
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    Juyst revieved this via email and thought i would share. What do the comm guru's here think about this particular radio?

    http://www.sportsmansguide.com/net/cb/cb.aspx?a=572929

  8. #48
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    That's a GMRS radio (more info about that model here), so you can see by their replies to my GMRS-related posting above what QuietShootr thinks of GMRS. In other words, their claims about the expected distances, especially for handhelds, are far over-blown. Here's a page where they did some reviews of GMRS devices to objectively test their claims. It doesn't look promising, especially in urban areas, or heavy terrain with thick vegetation. The best model they tested required an external antenna on both devices and "managed to communicate an incredible 6.15 miles, with 4.7 of those miles being over land and only 1.45 miles being over water."

    As shown in one of the links I provided, the main factors in determining the distance the signal travels are:
    - The output power of the radio.
    - The height of the transmitting and receiving antenna[s]
    - The position of the antenna relative to the Earth. (horizontal or vertical)
    - The terrain and vegetation.

    As HeavyMetal suggested, you might be better off saving your money and investing in a decent HAM setup. However, I decided that I'd start with a GMRS device and then move on to something more robust later. Just don't expect the thing to get 30 miles. That's not at all likely.



    Quote Originally Posted by 03humpalot View Post
    Juyst revieved this via email and thought i would share. What do the comm guru's here think about this particular radio?

    http://www.sportsmansguide.com/net/cb/cb.aspx?a=572929
    Last edited by HiggsBoson; 09-27-09 at 09:12.

  9. #49
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    .....
    Last edited by QuietShootr; 08-10-10 at 17:29.

  10. #50
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    Last edited by QuietShootr; 08-10-10 at 17:30.

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