Better antenna than the other inReach devices?

Out of all the direct comparisons (Mini 2, 66i, 700i), this is the only (first Garmin?) device with a flat antenna.

A bit of datasheet scrubbing shows different max power levels for Iridium between devices:

  • Mini 2: 31.8 dBm
  • 66i: 31.7 dBm
  • Montana 700: 31.7dBm
  • Messenger: 35.9 dBm

Clearly, all other devices share the same amplifier/antenna architecture while the Messenger is... different and 4dBm is a significant difference.

I am not an expert, but looking at and knowing the low altitude of Iridium satellites (780km / 485mi), the visible satellites (usually 2, often just 1 or up to 3) will most often be low on the horizon, leading to differences based on the type of antenna and device positioning.

While I haven't found a way to get Iridium signal levels on my 66i, some rough testing shows that the vertical position works much better than the horizontal position, which is expected for this type of antenna.

The Messenger is clearly intended to lay flat and I would expect the highest gain of the flat antenna to be straight up, where satellites are not going to be most of the time.

This leads to the basic question: when used in its best possible position (horizontal for the Messenger, vertical for the others), is the messenger actually going to yield better connectivity? With Iridium delays being noticeable, any improvement would be great.

Note: For the curious ones, in a somewhat difficult location (partially obstructed sky plus vegetation), my small sample with the 66i led to ~5min average sending time in the horizontal position and ~2min average in the vertical position. With a clear sky, the average is < 1min.

  • the higher power of 4dBm can be only because of the less efficient antenna design

    How do you come to this conclusion? Have you already tested it? Might it not just as well be that the new antenna design is more efficient and powerful than the old antenna design?

  • no, not tested, it is just my conclusion as power of iridium clients is defined by Iridium and should not be exceeded. So I assume simply here this is either some communication error (misinformation in data sheet) or there is some compensation allowed for some less efficient radiation diagram so the ERP is not exceeded.

    On the other hand, 4 dBm is not really measurable at the receiver side, so it will present itself to the receiver as any other similar devices probably