A quick trip the local Lowes Builder’s Store and I’ve found a solution to my tower-base electronics housing problem.
The electrician terminated with a 12 inch x 12 inch by 4 inch PVC weather-proof box when they pulled my feed lines, rotor cables and switch control cables.
Though I had mentioned I wanted enough room for a full lightening protection area, a large 3Kw dummy load, antenna switches, eventual tower control area and room to expand, the little box was what they put on.
I soon understood why, as rated boxes the size I needed were a major investment, as the manufacturer’s assumption was that these oversized boxes would be carrying very heavy power loads. Wall thickness were silly – 3/8 inch plate (9.5 mm) steel construction resulting in serious weight issues. Costs were well over $800 for the bare cabinet.
Remember in my climate the box will see everything from -40c to +40c (from -40 F to over +105 F), hight winds, will be buried under snow, will see rains in excess of 1 inch per hour (over 25 mm per hour) and basically about anything other than salt spray & sand storms that Mother Nature can muster up.
Sp when I spotted at the Lowes GRP (Glass Reinforced/Filled Plastic) lockable outdoor chest about the right size, for $60, it was a “no brainer.”
Tipped on its end the box is a very good size for the project, and the GRP material is very workable for adding entries and mounts.
I’ve started making templates for the Plywood back wall (would be the bottom in conventional usage) and shelves. I’ve selected a waterproof glue smooth finished plywood, which will be sealed with marine (spar) varnish.
A word of caution, using treated plywood to avoid the wood rotting or catching fire is no longer recommended where the material will touch metals other than copper or stainless steel. A the antenna switches are in Aluminum Cases, and there will be galvanized and mild steel in the box, it is worth the effort to surface treat regular waterproof plywood to avoid the corrosion.
The Polyphasers that have been temporarily housed in heavy poly bags will move into the new cabinet, as will the Array Solutions RatPack 6n antenna switch. All junctions that can be moved will go in the box, as will the ex-Navy Dummy Load (provided I can confirm it can take the temperature range).
Forward space for Tower Control, a Second RatPack 6n, and the electronics for a dedicated receive antenna will be included in the layout.
Turned on it side the door may not be as watertight as I want, but the addition of an EPDM (synthetic rubber) flap will address that risk.
Over the Electronics an interior Elvaloy Plastic membrane curtain will provide a second level of protection. Elvaloy is a PVC-like material where the usual plasticizers that make PVC sheet flexible are not used, rather a patented DuPont process makes for an all solids plastic sheet that has very low reactivity. So unlike EPDM it is much cleaner, doesn’t shed particles and retains its fire resistance & chemical resistance exceptionally well.
In the next week or so I will be test fitting a cardboard mock-up before building the actual interior wood frame.
Pictures will follow as the project goes along.