Transmit power table of different iR devices

Btw: dcr hasn’t released his M3+ review because of this: “I’m waiting for Garmin’s investigation into a satellite failure I had (kinda a big deal). It sounds like they’re close to having clarity on the issue (and some sort of details that I can include in the review, whatever they may be).” I am really curious about which “ satellite failure” he is talking about?! I haven’t noticed any satellite failure so far.

With just these numbers there is no way to tell the amplifier power or the reasons Garmin chose to use different output strength in these devices. 

They don't list whether it's EIRP (Effective Isotropic Radiated Power, which adds in antenna gain / efficiency) or just power at the amplifier output.

I would be pretty surprised if the Messenger Plus really put out 9.3 watts..  On the other hand if this is power at the amplifier output the different in output could be to equalize the transmitted output after antenna losses.  The Messenger antenna may need more power to reach the Iridium receiver.

A 1.48 watt transmitter with a very good antenna is better than a 9.33 watt transmitter with a poor antenna as the battery life would be much greater for the 1.48 watt device.  When they design these they balance size / battery / output power to get the result they are happiest with.

As long as any InReach messages are getting out and received by the satellite the power is adequate. 

I’d like to actually see official Garmin documentation showing those power valves, not just info from a 3rd party site. 9 watts for the messenger plus is wow, a lot. Most vhf portable transceivers are only 6. Nine watts off a little battery is a lot. It’s really hard to believe that little device can last a few days sending messages at 9 watts. My 6 watt vhf marine radio can’t.

-translated conversation-

Me:

[...] The point I would like to understand is: if I fall into a crevasse, which device offers me the best chance of sending a signal? Are they all the same in the end, or is one better than the others? I found that: Device Transmission power (Watts) inReach Mini 1.48 W inReach Mini 2 1.51 W inReach Mini 3 2.63 W inReach Mini 3 Plus 4.68 W inReach Messenger Plus 9.33 O GPSMAP H1 Plus 1.99 W However, these power distributions may not necessarily reflect the actual signal reaching the satellite.

Garmin Technical Support:

From a performance standpoint, the technical department has confirmed that there are no substantial differences in data transmission between the various inReach devices.

Among the various products, I would recommend the inReach Mini 3 or inReach Messenger Plus if you do not need navigation and map features. Otherwise, the most comprehensive device is the GPSMAP H1 Plus [...]

As I mentioned I would like to see official documentation from Garmin on output power levels, and why they are different. If garmin  are saying that there is no performance difference between devices then you would think the power outputs would all be fairly close to each other for equal or better battery performance, unless the different antennas require different power levels to achieve the same results. I even find it hard to believe that Garmin has even done any tests to back up that statement when they obviously never seem to test their software out. Why is the larger H1 only 2 watts and the messenger plus 9 watts? What is the power output of the original messenger?  I don’t think anyone is going to do a crevasse test on them but I’m waiting for hiking guy to hopefully do a dense forest rainy day test on a few Garmin devices together.

In the DCRainmaker Mini 3 review he mentioned the Mini 3 and Mini 3 Plus had different antennas.

I'm not sure if the 2 different antennas means they use slightly different frequencies which require different antennas or if they use a higher gain antenna on one of the units.  A search on Iridium satellite frequencies shows 1616 to 1625 mhz as the range.

It would also be interesting to see if the antennas are truly omnidirectional or if they exhibit gain in a certain direction.  That could be the reason for different transmit power levels so the reception at the satellite is about the same signal strength for each device in various orientations.

It wouldn't be hard for the RF engineers to measure the signal strengths from the antennas / transmitters to and from the satellites so I would guess the statement from the technical department is correct,

It would still be interesting to have DCRainmaker or Hiking Guy take a few of the units to a marginal location as you mention as a "show me" test.