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First event posted for 2019. Thanks and keep 'em coming!

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Bournville June 2nd 2019, 10am
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.That's it for this year, folks! See you all in 2019.

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    Receiver aerial

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    antoak

    Posts : 2
    Join date : 2018-03-22

    Receiver aerial

    Post  antoak on Sat Jun 30, 2018 6:57 pm

    As someone new to model submarines, I am building the Arkmodel German V11C, I thought I would start off with an easy (I asume) question. Can the aerial for a 72 Mhz receiver be run outside of the water tight compartment. This would give the aerial a straighter run and keep it away from other metal components.
    Many thanks
    Tony

    timgarrod
    AMS Website Webmaster

    Posts : 229
    Join date : 2013-04-23
    Age : 38

    Re: Receiver aerial

    Post  timgarrod on Sat Jun 30, 2018 7:05 pm

    not a problem just remember to seal the end to stop water getting in.

    i got them running both inside and out.
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    merriman
    Guest

    Posts : 197
    Join date : 2011-10-16
    Age : 70
    Location : Virginia Beach, Virginia

    Re: Receiver aerial

    Post  merriman on Sat Jun 30, 2018 11:49 pm

    antoak wrote:As someone new to model submarines, I am building the Arkmodel German V11C, I thought I would start off with an easy (I asume) question. Can the aerial for a 72 Mhz receiver be run outside of the water tight compartment.  This would give the aerial a straighter run and keep it away from other metal components.
    Many thanks
    Tony

    Yes. For the reasons you stated.

    But it's a good idea to isolate the antenna in the wet from the dry insides of the WTC. This is done by providing a conducting interface between the receiver and external antenna segments. That is done with a stud screwed through the after 'motor-bulkhead'. A nut at either end of the stud completes the connection between receiver and external antenna.

    You don't want to simply run the antenna between the receiver and the wet without a blocking interface between the dry and wet side of the antenna. Eventually water will get past the insulation and wick its way onto the receiver PCB, killing the device.

    Sounds impossible, but I've seen it happen. The unlucky guy (well, maybe not … he did get his boat back), during the post accident investigation, pulled the case off the receiver and everything inside was wet. Water, over a five year period, found its way!



    To isolate the bare antenna wire from the wet side, I smear RTV silicon rubber over the stud, nut, and bare antenna wire sandwiched between nut and washer. Note that I provide an antenna strain-relief by drilling a hole through the motor-bulkhead flange and reeving the antenna through it. Accidental pulling on the antenna wire won't lift it off the RTV insulation.



    David

    antoak

    Posts : 2
    Join date : 2018-03-22

    Receiver aerial

    Post  antoak on Sun Jul 01, 2018 7:26 pm

    Thanks for replies. Very useful information.
    Tony
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    cgbillb

    Posts : 2
    Join date : 2018-07-08
    Age : 78
    Location : Athens,Georgia

    Your Sub

    Post  cgbillb on Wed Jul 11, 2018 12:48 am

    David
    I have the same kit, but my WTC shafts did not line up very well with the prop shafts
    Where did you get your WTC? I see it lines up much better than mine
    Thanks for any help
    Bill
    Athens Ga.
    avatar
    merriman
    Guest

    Posts : 197
    Join date : 2011-10-16
    Age : 70
    Location : Virginia Beach, Virginia

    Re: Receiver aerial

    Post  merriman on Wed Jul 11, 2018 2:27 am

    cgbillb wrote:David
    I have the same kit, but my WTC shafts did not line up very well with the prop shafts
    Where did you get your WTC? I see it lines up much better than mine
    Thanks for any help
    Bill
    Athens Ga.

    https://www.rc-submarine.com/watertightcylinders

    David
    avatar
    cgbillb

    Posts : 2
    Join date : 2018-07-08
    Age : 78
    Location : Athens,Georgia

    Thamks

    Post  cgbillb on Wed Jul 11, 2018 3:34 am

    Thanks, that is where I go mine
    Bill

      Current date/time is Sun Jan 20, 2019 3:33 pm