Hi Grant
I do exactly the same: the plastic box with an 'O' ring seal, 'tails' of
cable passing through waterproof plastic cable glands, drain/breathing
holes, and all connections and PC boards inside the box treated with
conformal-coating spray.
Having tried and failed with all the other alternatives, I've found this
to be the only dependable way to keep outdoor equipment working in this
wet climate (other than positive pressurization with dried air... did
that too, for about 15 years).
But ferrite cores and an unbroken length of coax don't need any
waterproofing at all, just mechanical support and some separation from
the metal boom.
73 from Ian GM3SEK
>-----Original Message-----
>From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of
>Grant Saviers
>Sent: 10 February 2015 17:09
>To: Ian White; 'Jim Thomson'; towertalk@contesting.com
>Subject: Re: [TowerTalk] [Bulk] Re: Cutting a FT-240 type 33...in half
??
>
>Boxless is one way to go if the coax fits the cores, but as previously
>posted I use RG142 TFE coax for the choke windings.
>
>My latest design (in process) to avoid connectors going from the
rotator
>loop to the choke is to use watertight cable entry grips for that cable
>directly into the plastic choke box. These are available in sizes to
>fit most any coax and have an o-ring to seal the box hole. All
>connections in the box are soldered and glyptol'd. Likewise if #10 wire
>is used for the driven element connection, there are grips that go
small
>enough to clamp on it. In the end, I've never had a totally watertight
>box so do drill a 1/8" hole for drainage at the low point in the box as
>mounted. Note that stranded wire is not watertight, the water will
>wick down the strands. Adhesive filled ring lugs help prevent that.
>
>Grant KZ1W
>it doesn't rain much here in Redmond, WA, just all the time.
>
>http://www.mcmaster.com/#catalog/121/876/=vum4yl
>
>On 2/10/2015 3:35 AM, Ian White wrote:
>> But why use a box with bulkhead connectors anyway? That seems to be
>the root cause of all the problems.
>>
>> I never use bulkhead sockets on anything outdoors, because they
require
>stripping the coax which creates opportunities for water leakage, bad
solder
>joints and corrosion - all of which can be avoided by using inline
connectors.
>If you don't need someplace to fix bulkhead connectors, then you don't
>actually need a box either.
>>
>> Would there be any problem about using inline connectors and no box
at
>all? That would cure your space limitations :-)
>>
>>
>
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