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Most users ever online was 180 on Tue Nov 05, 2019 6:03 am

Latest topics

» Newbie needs advice!
Receiver aerial  EmptyToday at 1:58 pm by david f

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» 868/915 Mhz as a viable frequency for submarines.
Receiver aerial  EmptyWed Apr 10, 2024 5:48 am by tsenecal

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Receiver aerial  EmptyTue Apr 09, 2024 3:40 pm by david f

» ExpressLRS - 868/915 Mhz equipment
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Our users have posted a total of 12449 messages in 1981 subjects

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4 posters

    Receiver aerial

    avatar
    antoak


    Posts : 2
    Join date : 2018-03-22

    Receiver aerial  Empty Receiver aerial

    Post  antoak 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
    avatar
    timgarrod
    AMS Website Webmaster


    Posts : 259
    Join date : 2013-04-23
    Age : 43

    Receiver aerial  Empty Re: Receiver aerial

    Post  timgarrod 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.
    merriman
    merriman
    Guest


    Posts : 347
    Join date : 2011-10-16
    Age : 75
    Location : Virginia Beach, Virginia

    Receiver aerial  Empty Re: Receiver aerial

    Post  merriman 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!

    Receiver aerial  YnZqTU

    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.

    Receiver aerial  WHFMfS

    David
    avatar
    antoak


    Posts : 2
    Join date : 2018-03-22

    Receiver aerial  Empty Receiver aerial

    Post  antoak Sun Jul 01, 2018 7:26 pm

    Thanks for replies. Very useful information.
    Tony
    cgbillb
    cgbillb


    Posts : 3
    Join date : 2018-07-08
    Age : 83
    Location : Athens,Georgia

    Receiver aerial  Empty Your Sub

    Post  cgbillb 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.
    merriman
    merriman
    Guest


    Posts : 347
    Join date : 2011-10-16
    Age : 75
    Location : Virginia Beach, Virginia

    Receiver aerial  Empty Re: Receiver aerial

    Post  merriman 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
    cgbillb
    cgbillb


    Posts : 3
    Join date : 2018-07-08
    Age : 83
    Location : Athens,Georgia

    Receiver aerial  Empty Thamks

    Post  cgbillb Wed Jul 11, 2018 3:34 am

    Thanks, that is where I go mine
    Bill

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