And despite all that, the attenuation between TX+RX antennas is still 65.5dB! This must be reflections internal to my garage. Gotta re-run these measurements outside. Also, the angles on the shield are too shallow. I gave it a 130 deg opening, but the back is recessed from the active elements of the antenna, so this doesn't actually shield as much as it should. It'll be fun to see this on the radiation pattern measurement range! See before + after. Might have to use a wider shield. This is 2ft by 1ft sheet. The bolt pattern won't work for production use. In real life, if these shields are to be used, they'll just hang on via the 2 mounting bolts at the very center of the back of the antenna. You can just see their nuts pointing up in the last picture. Undoing all the other bolts while the antenna is inside the radome would permanently break the antenna. Spacers would get knocked loose, and you'd have to destroy the radome to re-align things. This antenna is entirely metric. Horizontal spacing between all bolts = 6cm. Spacing between the upper/lower bolts and the inner bolts = 20cm. Spacing between the inner bolts = 6.8cm. Holes are fine with 1/4" drill. Bolts are M10. --Bart