This rectangular sintered bronze grounding plate is the Glomex RA205 in the Giant version. The plate provides an electrical ground to the water for on-board electronic equipment and has an effective grounding area equivalent to 3.45 m² of copper.
The porous construction consists of sintered bronze microspheres, which provide a significantly larger contact area than the plate’s geometric surface. The profiled shape simultaneously increases the surface area and the strength of the construction. The grounding plate can be used when installing Loran, GPS, satellite equipment, and SSB radiotelephones, as well as for reducing radio interference. A documented 800 W SSB configuration requires two RA205 plates.
The plate measures 300 × 80 × 13 mm and has two mounting holes with a diameter of 9 mm and a center distance of 215 mm. It is mounted through the hull on a flat part of the hull that is always underwater, with the plate parallel to the vessel's centerline and the sloped ends facing fore and aft. On powerboats, it is placed on the aft third of the hull bottom close to the centerline, while on sailboats, it is placed on the aft half. Mounting on the transom is discouraged.
The location must not be immediately in front of a depth sounder, speed log, or other transducers, as turbulence behind the plate can affect the instruments. There must be access from the inside of the hull, and the drilling area must be clear of tanks, pipes, and wiring. If an edge is more than 3 mm from the hull, a flatter mounting location should be chosen.
During installation, the plate is used as a drilling template. Marine-grade sealant is applied around and in the mounting holes, but the back of the plate must not be covered. Do not overtighten the fasteners. For system ground or DC negative, use at least #8 AWG stranded copper wire with ring terminals. The connection from the battery's negative terminal must have the same dimension as the battery's negative cable. If copper foil is used for an HF installation, it must be at least 50 mm wide and routed as directly as possible without unnecessary bends.
The delivery includes two bronze bolts, two spacers, and three nuts. The grounding plate must not be painted. It should be inspected annually and can be cleaned with a stiff brush and bleach. Replace the plate if it is corroded or can no longer be cleaned satisfactorily.
Key featuresGlomex RA205, Giant version
Porous, sintered bronze
Dimensions: 300 × 80 × 13 mm
Effective grounding area: 3.45 m²
Two Ø 9 mm mounting holes with 215 mm center distance
Through-hull mounting below the waterline
For Loran, GPS, satellite equipment, and SSB radiotelephones
Can help reduce radio interference
Mounting hardware included
