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Resources for Antenna and Station Grounding

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by N0TZU, Mar 22, 2021.

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  1. N0TZU

    N0TZU Platinum Subscriber Platinum Subscriber QRZ Page

    Antenna and station grounding for amateur radio is a frequently discussed topic. For convenience in those, I’ve compiled a list here of what I consider to be authoritative and very useful grounding resources.

    First, an important safety note:

    The National Electric Code (NEC), from the National Fire Protection Association (NFPA), sets out the requirements for electrical systems and is used by most jurisdictions in the United States. Code requirements in your locale may vary, so consult the appropriate building authority if you have any doubts. Hire a local licensed electrician to assist you if you have any doubts about your ability to to safely and properly work on your grounding.

    Grounding Handbooks and Guides

    Grounding and Bonding for the Radio Amateur by Ward Silver, N0AX is probably the best handbook available for hams, with clear explanations and specific guidance for understanding and installing an effective, code-compliant grounding system. Available from ARRL or Amazon for $10 to $25 depending on format. https://www.arrl.org/shop/Grounding-and-Bonding-for-the-Radio-Amateur/ As a supplement to the book, ARRL has a webpage with a number of grounding resources (some are the same as listed here). http://www.arrl.org/grounding-and-bonding-for-the-amateur

    Another very good guide is by William Reeve at http://www.reeve.com/Documents/Articles Papers/Reeve_AntennaSystemGroundingRequirements.pdf

    Charles Rauch, W8JI has a number of informative and well illustrated webpages on station grounding (the rest of his site is also excellent). http://www.w8ji.com/station_ground.htm

    Here are a number of articles from QST on grounding, especially the three part series by Ron Block, KB2UYT that focuses on the lightning protection aspect: http://www.arrl.org/lightning-protection

    NEC Articles on Grounding for Radio Antennas

    NEC Article 810 addresses amateur radio, though some of Article 800 is also applicable. Here is an excellent, authoritative, yet approachable interpretation of those with many illustrations from Mike Holt’s free publications. (Article 810 starts on page 17). https://www.mikeholt.com/files/PDF/FREE_PDF_Radio_Television_Equipment_2020.pdf

    Audio Grounding

    Quiet audio connections to radios are more important than ever with digital modes. This reference from Jim Brown, K9YC covers proper grounding, shielding and cabling exhaustively, and much is also applicable for RF: http://audiosystemsgroup.com/SurgeXPowerGround.pdf

    Mobile Radio Grounding

    Perhaps the most extensive reference for grounding of mobile amateur radio installations (and much more about mobile setups) can be found at: http://k0bg.com

    Commercial/Public Service Radio Site Grounding

    A very informative guide on grounding for lightning protection by Ken Rand, a co-founder of Polyphaser is at https://members.rennlist.com/warren/LightningProtectionAndGrounding.pdf

    The lengthy R56 Standards and Guidelines for Communications Sites from Motorola is a comprehensive standard and guide book for telecom site grounding, among other related subjects. Versions can be found in on the web such as at: https://www.k3emd.com/downloads/Motorola_R56.pdf

    Other Grounding Resources

    Lightning Resources

    General information about lightning protection of people and structures: http://lightningsafetycouncil.org/LSC-Resources.html

    Here is an introductory technical paper on lightning and lightning protection with many references for additional reading. http://lightningsafety.com/nlsi_lhm...undamentals-of-Lightning-Protection-Rakov.pdf

    Misc. Resources

    If you like podcasts, the “Doctor Is In” by Joel Hallas, W1ZR had one on grounding: http://www.arrl.org/files/file/DoctorPodcast/April 13 2017 - Grounding.mp3

    Polyphaser, one brand of feed line protection devices, has many relevant “white papers” here: https://www.polyphaser.com/resources/white-papers

    General NEC Resources

    If one wishes to dive directly into the complicated NEC, the current version is available from the NPFA but it is expensive. (It might be available at your local library.) Fortunately, used past versions are very useful to read for educational purposes because changes from version to version are usually limited.

    I recommend purchasing the NEC Handbook rather than the bare NEC code because it adds many annotations, explanatory comments, and illustrations for much easier understanding. Available from used book sellers such as AbeBooks at https://www.abebooks.com.

    The NFPA makes the current version of the NEC available for free (registration required) online. There is only a limited amount of active time granted before being logged out, so looking up a specific item is usually best rather than attempting to read an entire article. At https://www.nfpa.org/freeaccess
     
    Last edited: Mar 22, 2021
    2E0DED, KX4O, AA5BK and 5 others like this.
  2. N0TZU

    N0TZU Platinum Subscriber Platinum Subscriber QRZ Page

    2E0DED, KD8EDC and W6KCS like this.
  3. KI5OMC

    KI5OMC Ham Member QRZ Page

    Great post! Thank you!!!

    73
    Glenn
     
    N0TZU likes this.
  4. K9WW

    K9WW Ham Member QRZ Page

    Yes! Thank you!

    Kirk K9WW
     
    N0TZU likes this.
  5. N0TZU

    N0TZU Platinum Subscriber Platinum Subscriber QRZ Page

    AK5B, W6KCS, KC9QBY and 2 others like this.
  6. WA7ARK

    WA7ARK Ham Member QRZ Page

    One of the more readable/understandable explanations of lightning protection I've seen... Debunks some ham OWTs...
     
    Last edited: Apr 1, 2021
    N0TZU likes this.
  7. W7UUU

    W7UUU Principal Moderator Lifetime Member 133 Administrator Volunteer Moderator Platinum Subscriber Life Member QRZ Page

    Great post Bob! Thanks for putting the effort into this.

    Dave
    W7UUU
     
    N0TZU likes this.
  8. K4SAV

    K4SAV Ham Member QRZ Page

    Yes, there is good info there. Read it carefully. One of the first things talked about are the 5 elements needed for lightning protection. The first 2 uncover the "elephant in the room" that everyone ignores when giving lightning protection advice. Here is that quote:

    "Strike termination devices must be suitable to accept direct lightning attachment and patterned to accept strikes before they reach insulated building materials. Cable conductors route lightning current over and through the construction, without damage, between strike terminations at the top and the grounding electrode system at the bottom."

    When you realize that coax and ladderline are not suitable conductors for lightning currents, what you do at the shack end of that conductor doesn't matter much. That makes dipoles hung in trees near your house problematic for lightning protection without major changes.

    Jerry, K4SAV
     
  9. WA7ARK

    WA7ARK Ham Member QRZ Page

    Suppose a ham has an antenna some distance from the house, has coax running from the antenna toward the house, with a dedicated ground-rod outside the house to which the coax shield is bonded before the coax enters the building. Further assume that the antenna ground rod is connected to the electrical service ground with the specified #6awg bonding wire.

    I dont think it matters if the coax between the antenna and the ground-rod vaporizes if lightning attaches to the antenna.

    The goal is to prevent the current pulse from following the coax through the wall into the house. The ground-rod and #6awg bonding wire to the utility ground should be sufficient to prevent that.

    Much cheaper to replace an antenna/coax than a house.
     
    K0UO and W6KCS like this.
  10. K4SAV

    K4SAV Ham Member QRZ Page

    If you add a ground system right below that remote antenna and tie the coax to that ground system before sending the coax toward the house that usually works. After the coax gets blown away, subsequent strokes will proceed along the main ionized path and if the house is far enough away those fingers that split off the main path won't attach to the house. Without that ground system right under the antenna there will be much more current headed towards the house.

    When I lived in Florida I had a pine tree about 100 ft from the house that took a strike. The current went down the tree and into the ground. It proceeded under ground (making some nice fulgurites as it went) until it found a sprinkler wire, went up the sprinkler wire into the house. It exploded the sprinkler system and took out the central heat / air and a few other minor things. I had to help the repair guy fix the problems. He wasn't used to having multiple simultaneous failures within a central heat / air system. He would replace one thing and that wouldn't fix the problem. I tested all the parts he replaced and told him if they were good or bad. That gave him enough confidence to proceed.

    Jerry, K4SAV
     
    AK5B likes this.

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