Just a NOTE, here: If you put the Reflector Element under the Dipole to make your NVIS Antenna, and it is of a FIXED Design and Installed to be a Permanent part of your Station, you might want to consider, how to make it non-Resonant so that you no longer get the NVIS Effect, when you do NOT want it. Here in Alaska We had a Fellow, KL7BB, (Crazy Bill) who did a lot of work in making a 40 Meter NVIS Antenna, to use during the Iditrod DogSled Race Comms during the Winters. He used the NVIS Version during the Days and the switched to the non-NVIS version after the Band changed, in the evenings. It was a real Pain to go put up the Reflector Element, and the take it down, when the Band Changed. What he came up with is a Pair of small Hi-Voltage Relays, that were DC Controlled, from the Operating Position, and broke the Element into three shorter non-Resonant sections, which then negated the NVIS Effect of the Element. Just Say'en.... YMMV....