Queried for a few similar looking antennae, and after fiddling with some numbers, these are the values I came up with. The resulting coverage map is a relatively close echo of what I’ve found while actually driving around.
BTW, I’m using slightly modified versions of the Sender and Receiver sketches from https://github.com/LilyGO/TTGO-T-Beam
(added EasyBuzzer.h to the receiver sketch, a piezo to pin2, to alert me when a packet comes through, so I don’t have to watch the OLED).
I’m sure these numbers aren’t the Real Deal, but they may help map out good locations for repeaters.
Gain on the antenna models I was comparing against were between 2 and 5. I can’t find specs on an antenna that looks like the one in the second image above, so I went with 3.5, since it looks more like the 5db units than the 2s.
No pigtails, the antenna is connected directly to the board, so I went with 0 losses, but sure, there still there must be some loss.
Not sure what threshold is, but changing from 0.22 to 0.035 threshold displays WAY more range than what I’m getting in the real world.
What’s interesting to see is this:
Virtual transmitter placed at the wide open hillside dog park across the valley reaches my wooded home (+160’ above) with no problem (4.4mi)
Switching the two, virtual transmitter at wooded home can’t even come close to reaching the dog park (-160 below). And I know this actually is true; I tried it with hardware yesterday, no good.
Sure, the tool doesn’t know everything, doesn’t account for all variables, but the predictions seem odd. I guess the only thing left is to leave a transmitter at the dog park, drive back home, and try it.
Are there firmware differences which have improved and/or changed any variables which might give use more accurate coverage estimates? For example:
I’ve been using the tool for a couple years, and it doesn’t look like small tweaks change the coverage maps a whole lot. All the same, it would be good to know how well the maps are matching the territory with the benefit of hindsight.