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  1. #31
    Join Date
    Aug 2011
    Location
    Perth, Western Australia
    Posts
    141

    Default

    Quote Originally Posted by nadroj View Post
    So someone whose business it is to do powder coating backs it against other methods. There's room for a little suspicion there.

    Have to agree when people come out with this sort of thing I take a step back and become suspicious but he had been highly recommended by others. I could never fault the work he did.

  2. #32
    Join Date
    Oct 2010
    Location
    melbourne, laverton
    Posts
    1,722

    Default tuff gel

    from my experience with aluminium parts and steel or stainless steel bolts. the only product that will give long lasting and effective protection against galvanic corrosion is TUFF GEL.

    https://www.tefgel.com.au/


    Ive seen it on ships ive been the engineer on. I always ensure that ever one on board these ships use it.

    For Example Fixtures and winches Fitted to a aluminium mast with Stainless bolts. Some things may have been there undisturbed for 10 or more years. The bolts that dont have tuff gel are a nightmare and often complexly seized. Any that have tuff gel liberally applied come out easy with the threaded aluminium hole in good order.
    I very skilled French marine rigger, maskarading as a captain put me on to it.

    As well as this If the Arial is bonded to a earth Circuit at all and theres any stay MVAC or small stay voltage on your earth circuit it really speeds galvanic corrosion up.
    aaron

  3. #33
    Join Date
    Sep 2012
    Location
    North Yorkshire UK
    Posts
    2,964

    Default

    Hi Aaron, Guys,

    As well as this If the Arial is bonded to a earth Circuit at all and theres any stay MVAC or small stray voltage on your earth circuit it really speeds galvanic corrosion up.
    One of the reasons that most of my antenna designs used insulated stainless steel elements on an aluminium boom. All the ham radio designs did, but the TV ones were galvanised steel screws through aluminium elements into an aluminium boom.
    Best Regards:
    Baron J.

  4. #34
    Join Date
    Dec 2019
    Location
    Adelaide
    Age
    53
    Posts
    11

    Default

    Quote Originally Posted by BaronJ View Post
    Hi Aaron, Guys,



    One of the reasons that most of my antenna designs used insulated stainless steel elements on an aluminium boom. All the ham radio designs did, but the TV ones were galvanised steel screws through aluminium elements into an aluminium boom.
    Sorry to ask, but what does insulated stainless steel element mean? Can you give an example? Thank you.

  5. #35
    Join Date
    Dec 2019
    Location
    Adelaide
    Age
    53
    Posts
    11

    Default

    Quote Originally Posted by azzrock View Post
    from my experience with aluminium parts and steel or stainless steel bolts. the only product that will give long lasting and effective protection against galvanic corrosion is TUFF GEL.

    https://www.tefgel.com.au/


    Ive seen it on ships ive been the engineer on. I always ensure that ever one on board these ships use it.

    For Example Fixtures and winches Fitted to a aluminium mast with Stainless bolts. Some things may have been there undisturbed for 10 or more years. The bolts that dont have tuff gel are a nightmare and often complexly seized. Any that have tuff gel liberally applied come out easy with the threaded aluminium hole in good order.
    I very skilled French marine rigger, maskarading as a captain put me on to it.

    As well as this If the Arial is bonded to a earth Circuit at all and theres any stay MVAC or small stay voltage on your earth circuit it really speeds galvanic corrosion up.
    aaron
    Interesting product. Do you just apply it using a finger as showed in a demo reel?

  6. #36
    Join Date
    Sep 2012
    Location
    North Yorkshire UK
    Posts
    2,964

    Default

    Hi Barnes, Guys,

    Quote Originally Posted by barnes3 View Post
    Sorry to ask, but what does insulated stainless steel element mean? Can you give an example? Thank you.
    What's to be sorry about ? Its a legitimate question !

    A Yagi antenna has a number of rods down its length at right angles to the boom, these are called "Elements". What they do is to control the radiation pattern of the antenna. The one at the back, usually the longest element, is called the reflector. Though often, particularly on TV antenna, it may be an array of three or more elements arranged in a "V" formation like this "<--".

    The next element is called the "Driven" element, and this is where the signal is extracted, or in the case of a transmitter, input, driven by the transmitter output. All the other elements are directors ! Their purpose is to shape the radiation pattern and direct the maximum collected signal to the driven element whilst reducing signals from unwanted directions. In the case of transmitting a signal, they direct the signal in the desired direction.

    The elements can be electrically connected to the boom, or in the case of my designs, electrically insulated from it using stainless steel elements. Unfortunately there is a lot of rubbish talked about antenna ! Basically any dissimilar metals in electrical contact will corrode. So the whole purpose of using insulation between them is to reduce or prevent any corrosion from taking place.

    Hope this helps.
    Best Regards:
    Baron J.

  7. #37
    Join Date
    Oct 2010
    Location
    melbourne, laverton
    Posts
    1,722

    Default fingure

    Quote Originally Posted by barnes3 View Post
    Interesting product. Do you just apply it using a finger as showed in a demo reel?
    with the finger its pretty sticky. a nitrile glove doesn't hurt a small stiff bristled paint brush if theres one lieing around.

  8. #38
    Join Date
    Oct 2010
    Location
    melbourne, laverton
    Posts
    1,722

    Default shore power

    Quote Originally Posted by BaronJ View Post
    Hi Aaron, Guys,



    One of the reasons that most of my antenna designs used insulated stainless steel elements on an aluminium boom. All the ham radio designs did, but the TV ones were galvanised steel screws through aluminium elements into an aluminium boom.

    ON a ship a major cause. Can be being connected to ac shore supply. Problems with the earth circuit. For safety sake the earth has to remain connected. You can safely isolate earth circuits with diods and capacitors. IM not sure if galvanic isolators would be suitable for or help aerials.

  9. #39
    Join Date
    Sep 2012
    Location
    North Yorkshire UK
    Posts
    2,964

    Default

    Hi Guys,

    Normally the tower would be earthed simply for lightening protection ! I used to have a 5/8" inch copper earth stake for the tower, until someone decided that they needed it more than me. Now how on earth do you pull a five foot earth rod out of the ground to pinch it ?

    The feed cables were fed through an earthed steel box, with the co-axial cable outer grounded in the box to both the tower and the baseplate. Touch wood I never lost a preamp or amplifier due to static or lightening. I used to run a kilowatt at one time ! A sixteen antenna array takes up a lot of space and has terrific wind loading. I replaced several rotators due to wind loading damage.
    Best Regards:
    Baron J.

  10. #40
    Join Date
    May 2011
    Location
    Murray Bridge S Aust.
    Age
    67
    Posts
    4,236

    Default

    Quote Originally Posted by BaronJ View Post
    Now how on earth do you pull a five foot earth rod out of the ground to pinch it ?
    If they're desperate enough, they manage to do it.
    We have a lot of new developments going on around here. Hot water systems are a favourite to go as is the copper plumbing and electrical wiring. Nothing unusual for a sparky to go in and run the cables one day and come back the next to finish, only to find yesterdays work gone!!!! Plumbers are now using a type of plastic tubing and crimping onto the fittings to combat thefts.
    Kryn
    To grow old is mandatory, growing up is optional.

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