Thanks for pointing this out.

Although moisture in a sealed concrete wall is probably not too big of an issue, Teflon tape is probably about as effective as tissue paper, like jerkey said, it is not at all designed to seal water. Specialty RF seal tape is probably the best way to go with this. One brand of tape is Coax-Seal ( Not a plug or testimonial but just to make it easy to search for, had to go Google diving for a bit to get the right set of search terms). It says tape, but a more accurate description would be a strip of road tar mixed with silly putty. After a couple of days, the individual wraps sort of "melt" together creating a more or less perfect seal, the only thing that damages the seal is direct sunlight, so inside a wall, this could realistically outlive the data retention of the flash chips. At about 2 dollars a roll, you'd probably have enough for 4 or 5 drops, and if you are putting drives in walls, extra 0.50$ a piece isn't significant.



Other thoughts on waterproofing the connection:



-Is there anything other than a few dollars stopping the Dropper from getting a female-female adapter so the jack is of the female type? It could be mounted flush to the wall reducing the chance of accidental damage or direct weather. As well as male-male USB cables are more common for any given random user to have.





-Force a glob of dielectric grease directly into the female connector (stole this one from a friend who does quite a bit of DIY car maintenance). Everything is totally sealed until a mating connector is pushed into the port. Each of the pins shear the grease out of the way and the contacts....well... contact each other. When the cable is removed, the grease smears out and re-coats any open surface.



*note*

Sorry, but the preview isn't working right for me. Please forgive the half dozen edits this will probably need to get the formatting right.