Fifteen or twenty years ago we had a need at the Medtronic Twin Cities Marathon to keep track in real time of the location of hundreds of injured or dropped-out runners across fifteen or so aid stations, a fleet of busses and a 40×80 foot hospital tent. This expanded to include a fleet of medical carts, and a lot of families who came to the Family Medical Information tent to ask about runners who did not finish on schedule. The possibility their runner was injured was worrying to them.
So we built a database in PostgreSQL called trivnetdb. The best way to access that database for rapid queries and updates by untrained volunteers was a web type interface. There was no good way using 1990s Amateur Radio technology for 20 or so users to access that database across a 26 mile race course.
Along came Icom D-Star DD mode. It supports ~85 kbps, half duplex. Just enough for a simple web front end. Our marching orders were to also be a backup system to the Internet, cell phones and the rented event radios. We had to do a software trick to get the ID-1 radio in the data trailer to accept multiple connections at once (dnat) but after that we were golden. We put in a series of DD mode “repeaters/nodes” on tall building around town and we were set.
Icom give us a few repeaters under a promo. Then were pestering us to support voice, which we decided was fun but not really necessary. We did try DV voice and it was cool- and we asked Ray for some more repeaters. We struck a deal- if we got North Dakota on the air he’s give us four more systems. One went to Duluth and one was for Little Falls. We did not know a soul in ND, but the ARRL (Ann Foster) got us in touch with the NDSU club. Reflector 53 (now XLX632A) came from TWINSLAN, our area digital data club, and they have it in a virtual hosting center. We have a partnership with the US Coast Guard Auxiliary local radio club who helped fund a repeater. The Digital Amateur Radio Club in Little Falls helped us grow. They run two nets- the Iowa D Star Net and the MN D-Star Net (Sundays @7:30).
We were delighted to see a new repeater module that supports FM. We use lots of FM at the Marathon -it is the great unifier and we love new, untrained and otherwise unwanted volunteers.
| Callsign | Location | Frequency | Mode |
|---|---|---|---|
| KC0TQI | East Ramsey Co. | 1299.000 | DD |
| KC0TQI A | East Ramsey Co. | 1285.100 | DV |
| WD0HWT | Minneapolis South | 1298.000 | DD |
| KE8TX | Downtown Minneapolis | 1251.000 | DD |
| W8WRR | Downtown St. Paul | 1249.000 | DD |
| W8WRR B | Downtown St. Paul | 443.350 | DV |
| KD0JOV B | West Metro | 442.900 | DV |
| KD0JOV C | West Metro | 145.150 | DV |
| W0ANA B | Ham Lake | 443.775 | DV |
| W0ANA C | Ham Lake | 145.405 | DV |
| KD0JOS B | Chaska | 442.1250 | DV |
| KE0MVE B | Ramsey, MN (Anoka Co.) | 444.525 | DV |
| KA0JSW B | Gem Lake (Northern Ramsey Co.) | 444.000 | DV |
| W1AFV B | Downtown Minneapolis | 442.950 | DV |
| Elsewhere in the state: | |||
| W0REA B | Little Falls | 444.000 | DV |
| KD0YLG B | St. Cloud | 443.850 | DV |
| KD0SWQ B | Fargo, ND | 444.000 | DV |
| N0EO B | Duluth | 442.200 | DV |
| N0EO C | Duluth | 147.375 | DV |
73’s NY9D
Ham Radio Tower Trailers 