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Contesting in Hawaii – H2O versus your antennas

Discussion in 'Amateur Radio News' started by KH6OWL, Apr 25, 2017.

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  1. KH6OWL

    KH6OWL Guest

    Thanks to Kimo Chun, KH7U, for this Article.

    Major contests held this past month include the ARRL International DX CW Contest and the CQWPX SSB Contest. The former had a number of stations operating from Hawaii in different categories. Jim Neiger, N6TJ, using Alex, KH6YY’s station on the north shore of Oahu, attempted to win a contest in the most recent of his decades of contesting. Unfortunately, based on claimed score submissions he fell short. He did admit that it is getting tougher to compete at that level as he gets older. My best wishes to Jim and it is great to know such an iconic contester. In the latter, conditions were poor but there were surprising spurts with some good openings to Europe on Saturday night. Eran, WH6R, whose call we used for WPX had a ball. I had fun on 40m before dawn working, 4E34A, A65DR, 9M2M, A73A, US1A, A96A, UP0L, 7Z1CQ, and RL4F among others using search and pounce, within 2 hours. I did have the luxury of using a custom built 4 element OWA (Optimized Wide-band Array) Yagi built by KH6ND.

    Maintaining equipment or making improvements always seems to consume lots of time when you’re trying to keep your station ready for contests or for em-comm. This is magnified if you’re trying to keep multiple towers and station setups going as we have at KH6YY. The elements always win…meaning water. Well, the Sun plays a role as does wind. Nothing like the repeated pounding that trade winds do to break or loosen something.

    Let’s get back to water. There is a rule: if it has threads on it and it will be outside use anti-seize compound. Besides plain zinc-plated and galvanized screws, this includes hot-dipped galvanized and stainless steel hardware. This is especially true when using dissimilar metals like stainless steel screws into aluminum housings (like Hy-Gain / CDE rotators). In Hawaii this rule is very critical. If you have any desire to remove the screw later you had better follow the rule. The one exception would be in high vibration situations where a thread-locking compound might be used instead. The thought that a screw will loosen due to the use of anti-seize is false. If loosening is an issue you should be using a locking washer or a jam nut. Be careful, however, different metals require different formulations of anti-seize compound AND ones NOT to use. You shouldobserve the specifications on the manufacturer’s label. If you have questions please feel free to contact me.

    I will be installing a new, replacement HAM IV rotator at KH6YY on the 10M Yagi tower. KH6U, Doug Morgan, prepped the rotator by removing its various screws and putting anti-seize (with Nickel particles for the S.S.) on them before reinstallation. He also prepped used a new product that is sold on-line from various sources and from DX Engineering. It is made by Rust-Oleum and is called Never Wet. It is a two part spray on process that leaves a seeming tacky coat, opaque in color. It is hydro-phyllic in that it repels water. He painted virtually the whole rotator with it. It was also used on a new custom steel mast clamp made by K7NV for one of his prop-pitch rotator units we use at KH6YY. The old one, while painted, had suffered badly in the weather over the years. See the picture. Water will not adhere to this coating. It just runs off as if never being wet, as the name implies. I had to touch up nicks I made during installation but I am hopeful this will add many years to the life of this clamp. I will be using this product liberally from now on. Demonstration videos show objects being dunked in water and coming up dry.

    [​IMG]
    2 inch ID custom clamp assembly for a small prop-pitch rotator from K7NV

    I am also replacing painted steel boom to mast plates on some large 15M Yagis with overly thick custom 13” x 18” aluminum plates I designed that Universal Manufacturers cut for me. It looks as if they used one of those neat water jet cutting machines. The old plates are coming apart in layers as if they were built in laminations. See the picture.

    [​IMG]
    Painted steel boom to mast plate for 8 el. 15m Telrex Yagi
    Needless to say I have lots of things to attend to. With some of these new changes to materials and methods to preserve them I hope to free up more time for other pressing maintenance issues. Until next time, have fun and keep on working on those antennas. BTW, are there any younger (not yet senior citizens) folks out there who would like to help and learn to climb and maintain antennas? Please let me know. I could sure use some additional good help both on and off the tower.

    73, Aloha,
    Kimo Chun KH7U

    https://oahuarrlnews.wordpress.com/2017/04/24/contesting-in-hawaii-h2o-versus-your-antennas/
     
    K3RW, PP8DA, YO4FKO and 7 others like this.
  2. W1YW

    W1YW Ham Member QRZ Page

    Rusticles:)
     
  3. KA0HCP

    KA0HCP XML Subscriber QRZ Page

    Well, yes. It's called "Intergranular Corrosion". The 'layers" are the crystal structure of steel.
     
  4. K8MHZ

    K8MHZ Ham Member QRZ Page

    More likely 'exfoliation' or 'lamellar corrosion'.


     
    KA0HCP likes this.
  5. K8MHZ

    K8MHZ Ham Member QRZ Page

    Accept no substitute:


    [​IMG]
     
  6. WA7PRC

    WA7PRC Ham Member QRZ Page

    Sometimes I use their lesser-known Aunty-Seize:
    [​IMG]
    :p:rolleyes:
     
    AF4RK and WH6OHM like this.
  7. K8MHZ

    K8MHZ Ham Member QRZ Page

    Or a torque wrench.
     
  8. VE7JBX

    VE7JBX Ham Member QRZ Page

    I think you mean 'hydrophobic' not 'hydrophyllic'. Painting any of your metal with hydrophyllic compounds like CaCl2 would be the opposite of what you want!

    Good suggestions though on the watch for dissimilar metals at fasteners. It may depend on how close you're situated to salt water spray there, but blue water sailboat experience was stainless steel and aluminium is a BAD combination. Each is good alone but at junctions, galvanic corrosion sets in fast.
     
    W1YW likes this.
  9. NC5P

    NC5P Ham Member QRZ Page

    I used the electrical product Penetrox A for dissimilar metal junctions, bolts, electrical connections, etc. I put it in the glow plug boots on my old VW TDI and never had to replace the glow plugs again. Mechanics were shocked that I didn't have trouble with them. They often had to replace both the glow plugs and the cables. It works as an anti-seize as well.
     
  10. WA6MHZ

    WA6MHZ Ham Member QRZ Page

    I saw THIS antenna on the North shore of OAHU. Trying to figure out what it is
    SURE looks great!! IMG_7255a.jpg
    looks like an EIGHT Element KT-34
     
  11. KM1H

    KM1H Ham Member QRZ Page

    Is it a stretched KT-36XA? Or ?

    It has the gull wing element look of the original KLM's that M2 bought decades ago.
     
    Last edited: Apr 27, 2017
  12. AA7TU

    AA7TU Ham Member QRZ Page

    For those on the windward sides of the islands, the persistent trade winds tend to cause corrosion mostly on one side of the tower, even if outside of the salt zone. Add the additional corrosion caused by the intermittent "vog" (volcano smoke = sulfur particles) and it is a daunting task to keep anything in working condition for long periods.
     
  13. N2YIR

    N2YIR Ham Member QRZ Page

    I would love to go to Hawaii and work on some antennas. I don't think the wife would be too keen, but that's what I would call a fun vacation. She just doesn't understand. BTW I'm only 36 and like climbing towers and working on antennas.
     
  14. WH6H

    WH6H Ham Member QRZ Page

    I had a small contest station at a QTH just off the beach in Kailua ( "windward Oahu") for fifteen years. I also "worked" up at the primo North Shore contest site in KH6XX, later KH7r with Kimo and the Oahu gang of contest ops. In Hawaii, Maintaining aluminum antennas, and steel towers is a full time commitment because EVERYTHING METAL IN HAWAII CORRODES....even aluminum. If you have a stainless steel screw in an aluminum boom it will rust and disenigrate in a matter of months. Today, I live in Jalisco Mexico up in the mountains and nothing rusts. What a contrast with KH6. Still love Hawaii!

    Aloha -- WH6H
     
  15. ZL4IV

    ZL4IV Ham Member QRZ Page

    There is only one anti corrosive product I use, it's a New Zealand product called RES-Q-Steel. Used on ships when I was engineer at sea and now on everything I bolt. after 20 years a nut with no sides left through rust still is able to be undone with pipe tongs. It is actually a by-product of paint manufacturing. I have used all the ones with metal ingredients but this is just the best. Made by Taubmans International.
     

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