The N9MEC gateway in Apple Valley is a somewhat unusual element of the metro APRS infrastructure. While it's ostensibly a TX gateway, it actually seldom transmits. It's direct coverage isn't particularly impressive; anything north of Burnsville is fringe coverage for this gateway. It's more than 10 miles outside of the metro freeway loop -- further than the Medina W0PZT-1 gateway, in fact -- but it handles the bulk of the metro packet traffic (and beyond).
Let's look at the stats for packets handled so far this month (11/21):
- W0PZT-1 (Medina): 19.3k
- W0YC-5 (Minneapolis): 16.8k
- N0HOY-10 (Arden Hills): 9.9k
- N0ALE-10 (West St. Paul): 6.3k
- N9MEC (Apple Valley): 47.4k
Personally, I consider any element of the metro infrastructure that handles over 1k packets a month to be "big". It would create a gap in either coverage or gating capacity if such a "big" element were to be lost. And this isn't a competition, it's a network where each element has a niche. I have no idea what makes the Apple Valley gateway such an effective magnet for digipeated packets. Even the IDs of the metro digipeaters seem to mostly end up at the N9MEC gateway. Here are a few examples I pulled off the aprs.fi site this morning (11/20/21). Again, you can click on any of these screenshots to enlarge them.
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K0LAV-8 to N9MEC
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| K1LEO-10 to N9MEC |
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| N0HOY-10 to N9MEC |
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| W0YC-5 to N9MEC |
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| AE0KW-1 to N9MEC |
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| W0PZT-1 to N9MEC |
Here is a recent path from my own gateway KD0TLS-1, bouncing off two digipeaters (which are also gateways) to end up in Apple Valley:
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| KD0TLS-1 to N9MEC |
Even the relatively-distant KC0QNA-1 digipeater in Green Isle sees it's ID packet bounced off the metro digipeaters to be gated in Apple Valley:
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| KC0QNA-1 to N9MEC |
It seems obvious that, for whatever reason, this RX-only gateway in Apple Valley is a critical hub for the amateur community. It's also gated over 1k ID packets from the Faribault N0QVC-1 gateway/digi this month. That Faribault gateway is a critical hub on it's own, providing baseline coverage for much of southern Minnesota. Having an alternate path to gateway for Faribault is important if we want a robust infrastructure in the State.
The N9MEC gateway is not without flaws, however. As others have pointed out, it seems to have a problem with delays in gating. This often shows up in tracking, where one or two packets from a mobile station appear to go backwards. What has happened is the N9MEC gateway has held on to the digipeated packet from the mobile station for a significant amount of time, and newer packets have already been gated by the time N9MEC sends that retained packet to the APRS servers. It's a minor annoyance, in my view, but it points to the possibility that N9MEC is operating beyond it's capacity.
Other elements in the metro infrastructure play different, but equally crucial roles. For example, they might pull in traffic from 'distant' areas of Wisconsin or places like Aitkin, Duluth, Mankato, Hinckley, etc. This connects us to the wider world via RF, allowing a metro operator with an HT to message far-flung stations without the internet. Other elements provide "fill-in" coverage in a congested environment. Yet other elements transmit messages from places like Turkey to RF-based operators here in the metro.
Even relatively minor gateways like mine still pull in several hundred digipeated packets over the course of a month, from Mankato to Rochester to Duluth. You can explore the world of APRS while making your own contribution to the amateur community's success by adding a gateway to the metro landscape. It won't grant you the glory and status of operating a repeater, but it's a lot easier and cheaper.
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