ad: chuckmartin

Military experts say radio amateurs "highly knowledgeable asset in HF communication"

Discussion in 'Amateur Radio News' started by W0PV, Oct 11, 2020.

ad: L-HROutlet
ad: l-rl
ad: Left-3
ad: Radclub22-2
ad: L-MFJ
ad: abrind-2
ad: Left-2
  1. KA2FIR

    KA2FIR Ham Member QRZ Page

    I see more than "a couple of hundred contacts" for many stations who submitted their logs for the 2019 Field Day results.

    https://contests.arrl.org/ContestResults/2019/Field-Day-2019-FinalQSTResults.pdf

    "The EZ NVIS is ready to deploy NVIS antenna based on an article by Carl Jelnick, N6VNG (SK). He based his design on the AS-2259/GR a miltary, dual band NVIS antenna set."

    https://www.hamradio.com/detail.cfm?pid=H0-014083

    https://static.dxengineering.com/pdf/WP-NVIS-Rev2.pdf

    https://en.wikipedia.org/wiki/Near_vertical_incidence_skywave

    Frequencies and propagation[edit]
    [​IMG]
    NVIS radiation pattern
    While the groundwave (blue) cannot propagate, the refracted skywaves (red) achieve HF coverage within the common first hop (~500km).
    The most reliable frequencies for NVIS communications are between 1.8 MHz and 8 MHz. Above 8 MHz, the probability of success begins to decrease, dropping to near zero at 30 MHz. Usable frequencies are dictated by local ionospheric conditions, which have a strong systematic dependence on geographical location. Common bands used in amateur radio at mid-latitudes are 3.5 MHz at night and 7 MHz during daylight, with experimental use of 5 MHz (60 meters) frequencies. During winter nights at the bottom of the sunspot cycle, the 1.8 MHz band may be required. [3] Broadcasting uses the tropical broadcast bands between 2.3 and 5.06 MHz, and the international broadcast bands between 3.9 and 6.2 MHz. Military NVIS communications mostly take place on 2–4 MHz at night and on 5–7 MHz during daylight.

    Optimum NVIS frequencies tend to be higher towards the tropics and lower towards the arctic regions. They are also higher during high sunspot activity years. The usable frequencies change from day to night, because sunlight causes the lowest layer of the ionosphere, called the D layer, to increase, causing attenuation of low frequencies during the day [4] while the maximum usable frequency (MUF) which is the critical frequency of the F layer rises with greater sunlight. Real time maps of the critical frequency are available. [5] Use of a frequency about 15% below the critical frequency should provide reliable NVIS service. This is sometimes referred to as the optimum working frequency or FOT.

    NVIS is most useful in mountainous areas where line-of-sight propagation is ineffective, or when the communication distance is beyond the 50 mile (80 km) range of groundwave (or the terrain is so rugged and barren that groundwave is not effective), and less than the 300–1500 mile (500–2500 km) range of lower-angle sky-wave propagation. Another interesting aspect of NVIS communication is that direction finding of the sender is more difficult than for ground-wave communication (i.e. VHF or UHF). For broadcasters, NVIS allows coverage of an entire medium-sized country at much lower cost than with VHF (FM), and daytime coverage, similar to mediumwave (AM broadcast) nighttime coverage at lower cost and often with less interference.
     
    Last edited: Oct 15, 2020
    K0FY, KD8DWO and M1WML like this.
  2. WB2PMC

    WB2PMC Ham Member QRZ Page

    same here. works fine.
     
    G3SEA, KE8BHP, M1WML and 1 other person like this.
  3. W1YW

    W1YW Ham Member QRZ Page

    ...and, then again, there are the select few (hams) who know more about NVIS than our simple discussions;-)
     
    WQ4G and M1WML like this.
  4. KQ9I

    KQ9I Premium Subscriber QRZ Page

    Actually, I recently read an article that about 10 service members a year do a CW course at Ft. Huachuca. The purpose, if I recall correctly, is so that the military has at least some people who can monitor CW transmissions by enemy forces as part of their signals intelligence training.

    This whole thread is another example of why QRZ.com forums is a toxic environment: nitpicking on semantics "What? Who needs software? Just fire up your Heathkit and throw up a wire!?!". No. Just no. This is a (to my mind very valuable) commentary by ham radio operators who are writing for a non-technical, non-ham, military audience. Their point, which is very valid, is this: The military has grown to become almost addicted to its hi-tech communications systems, to the point it has neglected HF in many respects. Servicemen and women use satellites and VHF almost exclusively (the Navy and Airforce may have a bit more HF capability, but mainly to comply and coordinate with civilian traffic control systems, not for use as wartime communications). I believe the lowest frequency used is a SINGCARS system on 30Mhz+. Current and former service members, please correct me if I am wrong.

    This begs the question: in a global conflict, where, for example, China (which recently launched a new naval destroyer w/ anti-satellite capability) or other countries knock out military satellites, what are the options? Iridium? How many ground units are prepared to switch to HF when they lose satellite connectivity?

    Consider this comment from an article at https://www.afcea.org/content/high-frequency-communications-features-highs-and-lows by Col. Stephen Hamilton, USA, and Chief Warrant Officer 4 Judy Esquibel, USA:

    "The growing dependency on SATCOM presents a problem: Because warfighters have been training for SATCOM, the training for effectively employing HF radio has dwindled; radios in the VHF and UHF range have continued to be used for line-of-sight communications.

    According to Ronald C. Wilgenbusch and Alan Heisig in an article in Joint Force Quarterly, HF is not a viable option to SATCOM, and they agree the declining amount of training is an issue. “The worldwide system of fixed HF transmitters and antennas that was once the mainstay of our HF communications systems is gone. … Even if it was still in place, the skilled HF operators needed aboard ships and ashore have been cashing retirement checks for years,” they said.

    Although the windfall of baby boomer retirements is challenging all government and commercial sectors, it has been especially hard on the computer industry. However, even though many HF-trained military members are separating from the services, a younger generation of enthusiasts is coming from the intersection of do-it-yourself aficionados and hackers. They are tinkering and creating small electronic devices, often using software-defined radios in their projects. They also are exploring various radio frequency-HF communication techniques and developing new hybrid skills.

    Even the National Natural Science Foundation of China concluded that HF radio use will lead to self-adaptability and an ever-changing environment. HF radio use also will encourage and leverage machine learning approaches, which will result in the development of smart anti-jamming techniques and equipment. In addition, foundation members believe heterogeneous networking—a combination of HF communications and satellite communications, military networks and civil cellular communications—will enable an integrated space-air-marine-ground communication network.

    HF communication using digital modes like FT8 is an example of how techniques evolve with digital communications. The ham and hacker communities have stated that evolving methods could enhance global communications while improving the use of limited spectrum.

    There is a trade-off, however. HF data rates are far lower than SATCOM data rates. Consequently, a backup plan must not only detail how to utilize HF transmissions but also outline what data should be transmitted.

    For example, it may not be possible to transmit the 2-megabyte battle brief of a PowerPoint slideshow using HF radio; however, the text from the slides could be transmitted without graphics over HF radio. In addition to bandwidth constraints, directing an HF signal to a specific location requires attention to many factors, including frequency, antenna configuration and power."

    But, no, let's crap on the authors of the article in the OP because they dare to mention programming radios (must mean those wretched Baofengs! Burn the heretics!)......
     
    K0FY, NW7US, K8PG and 11 others like this.
  5. N0TZU

    N0TZU Platinum Subscriber Platinum Subscriber QRZ Page

    Maybe I missed it - what journal were the OP mentioned papers published in?
     
    KC3PBI, M1WML and KA2FIR like this.
  6. W0PV

    W0PV Ham Member QRZ Page

    N0TZU and M1WML like this.
  7. AG5CK

    AG5CK Ham Member QRZ Page

    Do they still train with flintlock rifles? :)
     
    AJ6KZ, N3FAA, KK4HPY and 2 others like this.
  8. NX6ED

    NX6ED Ham Member QRZ Page

    My response to the militaries minds realizing that they are in a world of hurt if their satcom goes away: DUH!
     
    WQ4G, WN1MB, K9GLS and 1 other person like this.
  9. KG7RXU

    KG7RXU Ham Member QRZ Page

    Hi guys,
    I believe the article’s reference to software, drivers, and firmware has to do with requirements for MARS members to maintain and utilize certain digital programs.
    73!
     
    K0FY, W8SFC, N1EN and 2 others like this.
  10. KI5HNX

    KI5HNX Premium Subscriber QRZ Page

    I read that the Morse Code training was moved to Goodfellow in Texas when Ft. Huachuca stopped training around 2015 or so. Supposedly around 10 are trained per year. I would assume there are contingency plans to quickly scale that number upwards if necessary.
     
    G3SEA and M1WML like this.
  11. WA6VVC

    WA6VVC Ham Member QRZ Page

    Why can't we just work with the science of radio, tune and expand the art form, develop new technologies and have fun... maybe make a buck at it if marketable?
    Seems like to much emphasis of hooking up with multi letter agencies to save the world with a ham radio. Real or Hollywood? Is there anybody out there??
     
    AA0KM, G3SEA, KX4O and 2 others like this.
  12. K3IK

    K3IK XML Subscriber QRZ Page

    after the big EMP! How many hams have radios that will still work?
    How about we go back to semaphore and smoke signals. Tarzan did just fine with an empty log and a couple of sticks. Or was it Bomba?
    Still remember learning my Morse code using my Boy Scout neckerchief, long before I ever heard of ham radio. On a clear day with a set of binoculars and a hankie, can send a couple of miles ,at a reasonable rate, if needed, for emergency com. Now that is a true low tech resource. Just have to learn the code.
    BTW, how many know that Johnny Cash was a CW op during his military service.
     
    G3SEA, KX4O and M1WML like this.
  13. W5CJA

    W5CJA XML Subscriber QRZ Page

    HF is a fleeting fad for the military. It pops up every few years when a guy, like me, makes a presentation to a Colonel or two about HF effectiveness as part of a robust PACE plan. A push is made for more training but is usually forgotten or not included in next year's training plans. SATCOM and LOS comms are the primary focus for military communications. That's all well and good until you actually fight a peer level adversary that's capable of neutralizing SATCOM, GPS, etc. Depsite most units having HF equipment, most don't know how to put up a fan dipole or what to do if they are correctly installed.
     
    E75NET, WQ4G, AJ6KZ and 3 others like this.
  14. W4LLZ

    W4LLZ Ham Member QRZ Page

    Why would the military even bother with Morse Code - sending 30 wpm, when other digital modes can send 30 words per second? Yes, I do CW and other digital modes - I learned it as a personal accomplishment but I would never use it for tactical and strategic communication - not to say you can't, but its not as efficient as other options.
     
    KD8DWO, KK4HPY and M1WML like this.
  15. W4LLZ

    W4LLZ Ham Member QRZ Page

    Military experts say radio amateurs "highly knowledgeable asset in HF communication"

    Really? Gosh, wow. I didn't know that...as if we need the military to tell us what we already know...no thanks...they'd be the first ones to show up and shut down my station in time of war, or cease our firearms, and enforce marshal law.
     
    K9GLS and M1WML like this.

Share This Page

ad: MyersEng-1