Hi Put the box up on a pole where it gets a lot of sun on a regular basis. If it can breathe it will dry it's self out before a lot of water builds up. Simple vent hole in the bottom of the box and don't worry about much elese..
Bob -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Joe Gwinn Sent: Tuesday, May 15, 2012 8:35 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] wwvb weak on east coast especially when the pre-amps under water. At 10:49 AM +0000 5/15/12, [email protected] wrote: >Date: Tue, 15 May 2012 08:59:04 +0200 >From: Attila Kinali <[email protected]> >To: Discussion of precise time and frequency measurement > <[email protected]> >Subject: Re: [time-nuts] wwvb weak on east coast especially when the > pre-amps under water. >Message-ID: <[email protected]> >Content-Type: text/plain; charset=US-ASCII > >On Mon, 14 May 2012 18:01:01 -0400 >Joseph M Gwinn <[email protected]> wrote: > >> Modern outdoor enclosures use a filter of some kind, but the underlying >> principle is the same. > >I don't know what other types are around, but we use vents with >a gore-tex foil over them. Keeps water out but lets the case breath. >This prevents any pressure build up, which would then start to suck >water in from the seal. Gore-tex blocks liquid water (and dust), but allows water vapor to pass, so one can still get pumping and the accumulation of condensed water. Where are your enclosures used, and how exposed are they? As for the other methods, so far the following have been discussed: Box with long tube, where the tube volume exceeds the tidal volume of the enclosure, so outside air never manages to get to the enclosure. Typically, the tube is plugged with some cotton wool, to keep insects out. Box with short tube and filter/dessicant. The Gore-tex film is a filter, but not a dessicant. A box with medium tube and filter plus dessicant at the box end can be very effective, the medium tube reducing the rate at which the dessicant is exhausted. Box with short tube that opens on conditioned space. Totally hermetic box. Very effective, but very hard to do in practice, unless the box is small and strong. Box where positive pressure is maintained using dry air, so all leaks are outward and the dew point is never reached inside the box. Joe Gwinn _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
