APRS LESSONS LEARNED @ MC Marathon!
Its over!  14,000 runners, LOTS of hams, and our second year with APRS!  Last
year we had GPS on the LEAD, LEAD Handicapped, & TAIL chase cars. It was great,
but predictible.  This year we let APRS dead-reckon the predictible movements
of the chase cars and built 11 Trackers for the ambulances.  Lessons learned:
 * Completely "sealed" GPS/TNC/Radio boxes should have drain holes in bottom!
 * Maritime GPS units withstand immersion in water. TNC's don't
 * You can't duct-tape GPS trackers to vehicles in the pouring rain
 * New Marine Corps Tents (made by lowest bidder) leaked everywhere!
 * 14,000 runners, vehicles, etc + RAIN = MUD
 * Mag-mount GPS trackers wont stick to HUM-VEES.
 * Watching ambulances, which are parked for 99% of the event is BORING!
 * Ambulances with emergencies are under such close control by the ambulance
   direction net control, that he knows EXACTLY where they are anyway.
 * Ver 5.8 to 6.0 while doing manual tracking, do NOT default to current time
   but default to previous time.  IE, you have to retype the current time.
Of 11 units, 2 never quite got finished, one just couldn't be attached in the
rain, one leaked, flooded and died, the tinyest (running on AA cells)
died after 6 hours.  It rained from 5 AM until 1400.  Now for the good news:
 + We got double milage out of most APRS mobiles.  They put their GPS's in
   stand alone trackers for the ambulances, but kept their LAPTOPS and used
   the INPUT-MY command to manually report their position.
 + The 6.0 alt-IGNORE command let the entire event operate on 145.79 while
   ignoring ALL other non-participating stations.  THis keeps all APRS pages
   free of non-participants.  But the 6.0 transitioning in an out of
   this SPCL mode needs some more work.  Many stand-alone trackers are XTAL
   controlled, so you MUST plan on using the normal APRS freq for spcl events.
CONCLUSIONS:  Next year, we will probably go back to tracking the high-profile
chase vehicles and HAM mobiles that are always moving, rather than ambulances.
These 11 trackers now are permanent HAM radio assets in our community in
addition to the other 6 HAM mobiles that are permanently configured for APRS.
Next event is Army/Navy game football run from Annapolis MD to Philadelphia on
the first weekend in Dec.  In addition to chase vehicles, we hope to have an
aircraft equipped with GPS serving as a WIDE digi.