Dear Walter, Please see Gore's website where this is all explained.
http://www.gore.com/en_xx/products/venting/protective/index.html It is the way professionals do this, they don't use bits of gauze, wicks made from shoe laces or any of the other amateur solutions seen ;-) 73 from David GM4JJJ > On 21 Jan 2016, at 15:48, Walter Underwood <[email protected]> wrote: > > Gore-Tex might let moisture out, but it might let it in. Moisture migrates > from the more humid side of the membrane to the less humid side. It is a > pretty slow process. > > wunder > K6WRU > Walter Underwood > CM87wj > http://observer.wunderwood.org/ (my blog) > >> On Jan 20, 2016, at 11:39 PM, Ian White <[email protected]> wrote: >> >> The key point about a semi-permeable vent is that it blocks liquid water >> (and insects) from getting into the enclosure, but *always* allows water >> vapor to escape. As David points out, plain mesh won't do that under >> all conditions. >> >> In the UK, an equivalent to the Gore-Tex engineered vents is available >> from Farnell for about £5 ($7.50). Part numbers 2308394 (black) or >> 2308395 (grey). >> >> CPC normally has them a little cheaper (part numbers EN83188 or EN83189) >> but they are currently out of stock. >> >> Compared with the value of the KAT500 inside the enclosure, a properly >> engineered semi-permeable vent is a very good investment. >> >> >> 73 from Ian GM3SEK >> >> >>> -----Original Message----- >>> From: Elecraft [mailto:[email protected]] On Behalf Of >>> David Cutter >>> Sent: 21 January 2016 07:08 >>> To: Lewis Phelps; [email protected] >>> Subject: Re: [Elecraft] Remoting KAT500 to base of antenna >>> >>> Yes, but the weight of water eventually pushes it through - it's cheap >> but >>> not perfect. If you use a 20mm fitting as I did back then, water >> accumulates >>> inside until a large droplet forms then exits. The Gortex is better but >> more >>> $ £. >>> >>> David, G3UNA >>> >>> >>> ----- Original Message ----- >>> From: "Lewis Phelps" <[email protected]> >>> To: <[email protected]> >>> Sent: Wednesday, January 20, 2016 8:03 PM >>> Subject: Re: [Elecraft] Remoting KAT500 to base of antenna >>> >>> >>>> But might not this re-introduce the surface tension problem? >>>> >>>> Lew N6LEW >>>> >>>> >>>>> On Jan 20, 2016, at 10:18 AM, David Cutter <[email protected]> >>> wrote: >>>>> >>>>> From my work in the food industry (if memory serves), critter >> invasion is >>>>> prevented with 0.64mm square nylon netting. This is common in the >>>>> dress-making industry. (I think it can also be found as a stainless >>>>> steel gauze). This can be glued over a breather (drip) hole in the >> base. >>>>> >>>>> David >>>>> G3UNA >>>>> >>>>> >>>>> ----- Original Message ----- From: "Edward R Cole" >> <[email protected] >>>>> <mailto:[email protected]>> >>>>> To: <[email protected] <mailto:[email protected]>> >>>>> Sent: Wednesday, January 20, 2016 8:29 AM >>>>> Subject: Re: [Elecraft] Remoting KAT500 to base of antenna >>>>> >>>>> >>>>>> Fred, >>>>>> >>>>>> Your high desert climate will probably produce less condensation >> than >>> my >>>>>> sub-arctic/maritime environ. What I do for enclosures is to not >> seal >>>>>> them airtight but provide good drain openings which air can >> exchange. >>>>>> Of course the shelter is made to repel direct rain/snow. >>>>>> >>>>>> I suspected that my TR relays were "freezing up" at lower temps >> making >>>>>> the action delayed so I used some big aluminum Dale resistor >> strapped >>>>>> onto the relays to add direct heat by conduction. I happen to have >> 28v >>>>>> equipment so used 28v thru the resistors to produce heat within >> their >>>>>> wattage rating (used 40w resistors at both relays). Of course this >> also >>>>>> provided some heating of the ambient air of the enclosure which >> helped >>>>>> keep moisture from forming even in 90% humidity of the fall. It >> rains >>>>>> 8-days with one day off from August to October when temps finally >>> drop >>>>>> below freezing and rain becomes snow. You don't have anything near >>>>>> that. >>>>>> >>>>>> One thing I have noticed about drain holes in some equipment is >> they >>> are >>>>>> too small to allow water to drop free due to surface tension and in >> my >>>>>> environ that results in the weep holes freezing tight. I drill >> them out >>>>>> to 1/4 inch. Of course if you are prone to insect/archnid invasion >> that >>>>>> is problematic. >>>>>> >>>>>> PS: I lived five years in the high Mojave Desert so know all about >>>>>> "critters of the desert" (never stick your hand into a confined >> space >>>>>> before kicking it to see what crawls out or "rattles"! >>>>>> >>>>>> 73, Ed - KL7UW >>>>>> ------------------------------------------ >>>>>> >>>>>> 3. Reno/Sparks is a high desert [4,500'] directly adjacent to the >>>>>> Carson Range and Sierra Nevada [really big mountains]. Winter >> temps >>> go >>>>>> down into single digits, it does snow/rain. Should I do anything >> to >>>>>> prevent condensation in the weatherproof box [light bulb, drain >> hole, >>>>>> ???]. >>>>>> >>>>>> 73, >>>>>> >>>>>> Fred K6DGW >>>>>> - Northern California Contest Club >>>>>> - CU in the Cal QSO Party 1-2 Oct 2016 >>>>>> - www.cqp.org >>>>>> >>>>>> >>>>>> 73, Ed - KL7UW >>>>>> http://www.kl7uw.com >>>>>> "Kits made by KL7UW" >>>>>> Dubus Mag business: >>>>>> [email protected] >>> ______________________________________________________________ >>>>>> Elecraft mailing list >>>>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>>>>> Help: http://mailman.qth.net/mmfaq.htm >>>>>> Post: mailto:[email protected] >>>>>> >>>>>> This list hosted by: http://www.qsl.net >>>>>> Please help support this email list: http://www.qsl.net/donate.html >>>>>> Message delivered to [email protected] >>>>>> <mailto:[email protected]> >>> ______________________________________________________________ >>>>> Elecraft mailing list >>>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>>>> <http://mailman.qth.net/mailman/listinfo/elecraft> >>>>> Help: http://mailman.qth.net/mmfaq.htm >>> <http://mailman.qth.net/mmfaq.htm> >>>>> Post: mailto:[email protected] >>> <mailto:[email protected]> >>>>> >>>>> This list hosted by: http://www.qsl.net <http://www.qsl.net/> >>>>> Please help support this email list: http://www.qsl.net/donate.html >>>>> <http://www.qsl.net/donate.html> >>>>> Message delivered to [email protected] <mailto:[email protected]> >>>> Lew Phelps N6LEW >>>> Pasadena, CA DM04wd >>>> Elecraft K3-10 / KXV144 / XV432 >>>> Yaesu FT-7800 >>>> [email protected] >>>> www.n6lew.us >>>> >>>> Generalized Law of Entropy: Sooner or later, everything that has been >> put >>>> together will fall apart. >>>> >>>> >>>> >>>> >>>> >>>> ______________________________________________________________ >>>> Elecraft mailing list >>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>>> Help: http://mailman.qth.net/mmfaq.htm >>>> Post: mailto:[email protected] >>>> >>>> This list hosted by: http://www.qsl.net >>>> Please help support this email list: http://www.qsl.net/donate.html >>>> Message delivered to [email protected] >>> >>> ______________________________________________________________ >>> Elecraft mailing list >>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>> Help: http://mailman.qth.net/mmfaq.htm >>> Post: mailto:[email protected] >>> >>> This list hosted by: http://www.qsl.net >>> Please help support this email list: http://www.qsl.net/donate.html >>> Message delivered to [email protected] >> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[email protected] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to [email protected] > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
