Steve - IF you desire a waterproof mast enclosure, used by SSB-Electronic GmbH for their mast pre-amplifiers and downconverters http://www.ssb.de/amplifiers/preamplifier/vox/100w I purchased empty mast enclosures (2) from SSB Germany, about 10 years ago.

UK-based Uputronics sells a Mast Mountable Enclosure for £34.34 They have a number of other useful items. https://store.uputronics.com/index.php?route=product/product&path=63&...

The other sourcing option, are outdoor low-voltage enclosures used in the CATV, Telco industry, and Electrical trades. A well-stocked electrical supply house will have Plastic & Metal boxes.

Outdoor Patio Deck resellers sell an enclosure for low-voltage patio lights. http://www.thedeckstoreonline.com/low-voltage-enclosure-outdoor.html#.WdF1l3...

Perfect Vision enclosure for TV/CATV users. https://www.solidsignal.com/pview.asp?p=PVCB2GRY&utm_source=google&u...

I have “re-purposed” obsolete CATV (1970/1989) aluminum “line enclosures” used on their outdoor distribution lines — these are very nice. Rarely sold at hamfests, as “plug-n-play” crowd did not understand potential usage. Many of these units were replaced over last 20 years as Cable industry updated their systems in 1990s for 2-way amplifiers (Internet / Home Security service delivery).

greg, w9gb ===

Looking to move my two mast mounted preamps into an enclosure. Who knows of a good mast mount enclosure handle 2 Advanced Recv'r 160 Watt Mast Mounted Amateur Preamp's inside? The preamps are 5" wide and 2-1/2 deep. Steve, NS3L