Horn Pond Mountain field test
A pocket-size MeshCore node hung in a tree on Horn Pond Mountain in Woburn reached a North Cambridge repeater directly and was heard by up to 22 listening stations, from Cambridge to Deerfield, NH.
Where
| Spot | Position (tap for map) | UTM | Altitude | Notes |
|---|---|---|---|---|
| 1 | 42.45865, -71.15734 | 19N 322619 E, 4702956 N | 214 ft | First tests, node hung in a tree |
| 2 | 42.45889, -71.15756 | 19N 322602 E, 4702983 N | 232 ft | Pocket and tree tests, about 35 m north-west |
The spots are on the Horn Pond Mountain trails in Woburn, south of Horn Pond. From spot 1, the North Cambridge repeater is 4.4 miles away at 165° (south-south-east), Boston City Hall 8.5 miles at 144°, and our rooftop repeater 1.5 miles at 10°.
What was heard
From the New England analyzer, about a hundred listening stations across the region. Stations are distinct listeners; sightings count every copy they heard.
| Time (ET) | Post | Region | Stations | Sightings | Hops | First repeater | Notes |
|---|---|---|---|---|---|---|---|
| 11:51 | Public message about the test | none | 22 | 43 | 12 | CMB-NoCa-LinearPk-Rptr, North Cambridge, 4.4 mi | Replies from Cambridge (11:51) and Deerfield, NH (11:59) |
| 11:51 | #ma-hc health check | east | 11 | 21 | 6 | CMB-NoCa-LinearPk-Rptr | |
| 11:52 | #ma-hc check MHC-2B50FA | east | 12 | 29 | 6 | two other repeaters | 4 repeats heard on the node |
| about 12:00 | Test in my pocket (spot 2) | east | 0 | 0 | - | - | No repeat heard on the node |
| about 12:02 | #ma-hc check MHC-9DC8F9 | east | 0 | 0 | - | - | 1 repeat heard on the node; no station reported it |
| 12:05 | #ma-hc check MHC-5D39ED, back in the tree | east | 12 | 30 | 8 | CMB-NoCa-LinearPk-Rptr | 4 repeats heard on the node |
| after 12:05 | Test in tree (spot 2) | east | 0 | 0 | - | - | No repeat on the node; no station reported it by 12:12 |
Compared with home
| Time (ET) | Post | Stations | Notes |
|---|---|---|---|
| 10:09 | From home: Public test | 1 | Only our own receiver |
| 10:24 | From home: Public question | 26 | Through our rooftop repeater |
What we learned
- Height and a clear line south work. Hung in a tree with a view of Boston, the node reached a North Cambridge repeater directly, and its posts travelled up to 12 hops.
- In a pocket it did nothing. The same node in a pocket was not repeated at all. Even in the tree, about half the messages got through: on a link this long, each one is a coin toss, so a node here needs a better antenna than a pocket radio's.
- Region scope costs reach. The unscoped Public post reached 22 stations; the region-scoped health checks reached 11-12. Most repeaters around Boston do not forward region-tagged traffic yet.
- This hill could link Woburn to Cambridge. A small node here, 1.5 miles from our rooftop, would give Dispatch alerts a path toward Boston that the rooftop does not have today.
Want to test your own spot? See the blog and Repeaters, or join the Greater Boston Mesh community.