If there is enough demand, I will happily build a Frequency Agile RTG!
Allen
VHS
Allen, RP:
Since I know and comprehend just enough of the tech side of APRS to be dangerous
, I'll jump in as sort of an end-user rep in the development of a racing APRS set-up. Not sure of the size of the market at introduction, but if an RTG-FA is made, perhaps it would be buildable to reach a wider market.
Here's the background: SARL races take place in a variety of locations, and due to the design (open course X-C race that starts and ends at one airport, with most courses between 100-150 miles in length...various shapes, but a 75-100 mile radius of the start/finish is a good basic geo area to start with).
Many races invite local residents to view the start/finish, with BBQs, parties etc. However, that's a limited view of the race. Internet video feeds of the start/finish have also been tried (and continue when able) to reach a remote audience. A tracker-based feed to the internet would be one way to augment the start/finish viewing, both local and remote.
Some racers carry data loggers for post race review, and for potential foul resolution, but there is no live output. The SPOT interval is too long at 10 minutes. The iPhone Tracklog app can show multiple tracks, but the site is arduous, and it all depends on the phone connectivity (GPS and 3G).
Therefore APRS seems like the way to go. Whether all racers would adopt APRS (HAM license and $$) is unclear. The league would probably not be able to afford a stock of issueable trackers, and we'd run into license and ID issues in that scenario. With good PR, we could probably overcome the license aversion (hassle factor). If an affordable, plug and play tracker were available, it could be a hit. Combined with an airborne digi and a start/finish igate, it could make real-time race tracking a reality.
One question on the FA feature. Does it mean we can pick a discrete frequency for racers to transmit on? Are there alternate APRS freqs available to choose from, or would we have to apply for a freq assignment? Just don't know enough about this aspect of HAM and APRS. I know the goal is to not bury a local area on 144.39 for an hour with an insane number of transmissions...just don't fully know how to make a dense race transmission environment a friendly neighbor.
A wish list for the race+X-C tracker might be:
- Small portable form, as in the current RTG
- 12V adapter as in the RTG...but perhaps make that adapter removable, with the option to run it from a 9V batt, and thus add the ability to plop it up on the dash for the race with no power wires.
- Integral Power switch as an OEM feature, especially if we add the 9V batt power option.
- Integral Pri/Sec profile switch as an OEM feature, so a second race profile could be added to a basic X-C profile (so we can beacon in a friendly manner en masse)
- The last piece is the transmission antenna. For total portability, the pie-in-the-sky is a cockpit placeable antenna that could hit digis at 500 agl and below. The airborne digi may help that, but this is still a challenge. Racers will not want to add an external antenna (drag), so a jpole in the wingtip may be an answer...that would leave just one cockpit pentration (for the ant lead) and one connection at the unit (in batt mode). Maybe a canopy antenna (stickable to the inside of the canopy) would be a nice option too (if that works, and doesn't create an RF hazard to the pilot/pax noggins).
This type of set up (portable and cockpit placeable with min connections) would fit the widest variety of aircraft, some of which would not be able to fit jpoles in wingtips. Racers are modifiers, but simple is good, to allow their efforts to focus on speed mods versus trackers. That feature set may give it a wider appeal as well, and thus make the R&D worth it, as racers number in the 100 range, and you'll need a much bigger market to justify the development.
Just thinking out loud Allen, and just one guy's thoughts. I'd welcome comments and cross talk to enhance the discussion and make it more productive.
If better, I can start this as a stand alone thread, or Sam, if you'd like to do that as a mod with this post, please feel free!
Thanks, and Cheers!
Bob