[aprssig] smartbeacon fast rate

[Wes Johnston, AI4PX]

I've seen in several posts in the past few days a couple of people
setting their fast speed from anywhere 65 to 90mph (presumably) in
automotive use.

I set mine much lower, about 45mph.  When I set it I ask myself this
question... will I be turning off of a major road at more than XX
miles per hour?

Corner pegging is great.. but in the end it makes my car a little more
"chatty" than it would be if travelling in a straight line.  I want to
make my car as less chatty as possible when I'm travelling on the
interstate for example.... so I set my fast speed just above the point
at which I expect to exit the interstate or turn off the main highway
into McDonalds.  Honestly 35 to 45 mph is fine.  Check your
speedometer the next time you turn off a main road into a subdivision
or mall parking lot.  5mph above the fastest speed you'd expect to
make a 60 or 90 degree turn is where you want to set the fast beacon
speed.

For me, it's slow rate at 1 mph, high speed at 45mph.  If I'm
travelling faster than 45, I won't be making any sudden turns, so why
allow corner pegging to be enabled at hiway speeds?

The way I learnt this was observing my basic stamp running on a laptop
as I travelled between two main towns.  I made it print out a bunch of
variables and began to see WHY it was triggering so much.  There are
so many variables in smart beaconing that w/o a display, it's hard to
know which thing caused it to beacon.  One outstanding reason was I
had the high speed rate set over 65mph, and was travelling 50mph on a
stretch of road that had a long slow turn in in.  The doggone thing
beaconed twice before I got out of the curve!  It occurred to me that
if anyone was dead reconing me, they wouldn't need to see my car
pegging even once in a long slow curve in the road... they'd _know_ I
was on the interstate and that I had to be going down the road.  Now
on city surface streets, it's a different story.

Just food for thought.
Wes
-- 
In theory there is no difference between practice and theory.