Focus on Competition - 2012/10

As I mentioned in
a previous column,
from time to time
I’ll be addressing
questions that
are either about
new technologies
or may seem
confusing.
Through emails and phone calls, I
can get an idea of what issues our
members are most concerned about.
I’ll take this month to put a few of
them out there.
I have fielded several questions
pertaining to using spread spectrum
for surface and air at the same time.
It’s different than what we’ve been
accustomed to since the beginning of
RC. There’s now no difference in the
radio frequency between air radios
and surface radios.
Spread spectrum is spread
spectrum; there is not a distinction
between the different categories
anymore. It doesn’t matter whether
you’re flying an airplane, running a
boat or car—they all play together
now without interference. Today, the
only difference in radios is the power
output between surface and air.
Normally, a surface radio will have
a lower power output which translates
directly into shorter range. This is no
problem when you run a car or boat
with airplane equipment, but if you
fly with surface equipment you may
encounter range problems, so keep
this in mind if you’re mixing systems.
One more thing to consider if
you’re using the new spread spectrum
equipment is servo compatibility. The
servo itself will be no problem, but it
has been recommended for some time
now to use six-volt (five-cell) battery
packs with spread spectrum receivers
stemming from their higher cutoff
voltage. Several servos still in use will
not tolerate continuous six-volt power
and will eventually give up the ghost.
Check the performance data on the
servo before you install it.
Another often fielded question
pertaining to spread spectrum radios
is how many can be turned on at the
same time and still be safe. The jury
is still out on that one. Your best
bet is to follow the manufacturer’s
recommendations. There recently
has been some testing completed to
determine the number.
An article written in 2008 by Cal
Orr explained in detail the testing he
did where, if memory serves me, he
had more than 100 spread spectrum
radios (by various manufacturers) all
on at the same time while flying, with
no apparent interference.
Also, there was an attempt to set a
record at the Southeast Electric Fun-
Fly meet for the most RC airplanes
in the air at one time. I can’t recall
the number, but it was an astounding
amount of radios to be on at the same
time; 150 to 175 comes to mind.
I’m sure testing will continue and
I’m hoping we arrive at a number we
can all live with. It’s still better than
dealing with frequency pins.
On a side note, I’m often asked
what the AMA recommends in terms
of requiring pins for spread spectrum
radios, and whether impound is
required. Of course, what a club does
is up to the club, but we recommend
continuing with an impound for
the 72 MHz fliers and having pins
available for the spread spectrum
fliers. Many still fly on both, and you
don’t want to get caught turning on
your 72 radio without a pin. Consider
using a pin until spread spectrum
becomes universal.