Direct mount antenna bad idea?

pe1mew
Sun, 01 Feb 2026 10:32:07 +0000

Hi, my 2 cents:

BombayBill:

The Metal Box Effect: The metal enclosure of the RAK gateway acts as a massive, asymmetrical ground plane. This pulls the “resonant frequency” of the antenna.

Both 5.8 860-915 antenna and McGill 5.8 915 antenna are collineairs and their radiation patterns are independant from the enclosure it is mounted to. Because the enclosure is under the antenna, influence can be neglected. For as far as I know there is no “The Metal Box Effect” in the installation you describe.

BombayBill:

**The “Tuned” vs. “Untuned” Performance: **with McGill antennas

I have a strong believe that the words “Tuned” and “Untuned” are incorrectly being used. Any antenna is resonant or tuned to the frequency it was made for. therefore the words “Verified” and “Unverified” are better in this context. I believe that McGill verifies the antennas they have manufactured in China. That sure helps gain confidence in the product they sell.

You may compare this with: why commercial guys sell antennas with a gain in dBi and RF engineers use dBd.

In all my years as RF engineer I have not observed significant difference between an antenna on the top of a mast or a antenna on a enclosure on the top of the mast. Here i explicitly state that no objects (antennas) are in close proximity to the antenna. This however may be the case with the RAK7249 enclosure.