REPORT
#5
DETECTOR TESTS... ARE THEY MEANINGFUL?
A FEW QUESTIONS TO HELP YOU FIND THE BEST RADAR DETECTOR
1. Are the test samples honest?
For
its February, 1979, test, Car
and Driver requested samples from detector makers. I delivered an Escort (I was president of that
company then), Fuzzbuster delivered a test unit, and ten
other makers provided theirs by various means.
During
the test, C/D got
suspicious of the Fuzzbuster, so the tester went off to
a local discounter and bought a supposedly identical model
over the counter. The factory sample vastly outperformed the store-bought unit. So he drilled the rivets out of both Fuzzbuster
cases to expose their circuitry. They were completely different inside. Fuzzbuster
had, in effect, stuffed an Escort motor in a Fuzzbuster
case, and sent the souped-up cheater off to the races.
Fuzzbuster
got caught. C/D
printed the story. There were pictures. Justice was done.
The
point here is that tests are make-or-break showdowns for
all detector makers. The temptation to submit a hot sample is simply
too great for some to resist.
Who
gets hosed if the maker pulls a switcheroo? Not the magazine. Only the consumer, when he pays up for the winner, only to discover he doesn’t
get the protection promised by the test.
To
keep the results honest, the tester must buy the units
the same way customers do, at retail. And it must be a "blind" buy; that is, the maker
can’t know which
retailer will be contacted. This is an essential precaution. Because testers always want the newest model, the
one that isn’t on all the shelves yet. So they ask the maker "Who has it." "Well, we know that XYZ will have one by Monday." It’s too easy to supply a "special" test unit when
you know exactly where to send it.
Buying
blind from us is simple.
Any tester can have his mother-in-law call 1-800-331-3030.
2. Are the test conditions well controlled?
If measurements
aren’t repeatable, they aren’t measurements. To get repeatability,
conditions must be exactly the same run after run. Here are just four of many requirements:
A: All hand-held
radar guns and laser guns must be held in fixtures. This assures that each oncoming detector faces
the same beam intensity. I would be surprised if anyone could hold a radar or laser gun within five degrees of aim
run after run all day long. But on a one-mile range, a five degree shift means
you hit one detector with the hot part of the beam, and
shoot 460 feet over the head of the next one. Even if they’re equally sensitive, one detector
will respond and the other may not.
B: The test range has to be empty of moving vehicles,
except for those involved in the test. Moving traffic
reflects radar unpredictably; actual highways are never
empty enough for repeatable results. Even construction equipment operating near the
road can bounce the beam to the advantage of one detector.
C: No detector-maker’s reps allowed near the test. It’s too easy for someone to conceal a transmitter
that would signal his
detector at the opportune time.
D: The test range can’t run out of room. Even the best testers screw up sometimes. For
its September, 1995, test of cheap detectors, Car
and Driver threw a V1 into the mix, supposedly to
show how much protection you lose by buying low-cost units.
Unfortunately, the test range was sized for the weak performers;
V1 maxed out the range at 2.4 miles on both X and K bands.
No one knows how much warning distance it really
offered because the testers had no room to measure
more. Worse yet, the author simply presented the results
in the magazine, with no mention that V1 performance was
limited by the length of the test road, not by its sensitivity.
Throw
the red flag when you see bar graphs running the full
length of the grid. In that 1995 test, the readers came
away with the mistaken notion that cheap detectors perform
almost as good as the best radar detectors on some tests.
3. Does the test mimic the consumer’s problems? Radar
behaves like the headlights of an oncoming car. Like a light beam, radar travels in straight lines,
and it’s completely blocked by solid objects. When oncoming
headlights are still behind a hill, you see only a faint
glow, which brightens as they approach the crest.
Once
headlights break over the hill and into the open, you
can see them miles away, and the driver of that car can
see yours. Same
for radar. Your detector sees radar, the radar sees you,
the game is over. Those long-range alerts in some detector
tests—five miles, seven miles, or more—are irrelevant
for this simple reason…detector users don’t get nailed
at five miles, or seven. It’s so easy for a detector to see unobstructed
radar coming that radar enforcers don’t even try beyond
a half mile or so. Instead, they hide in ambush, waiting till you
are
up close.
A: Does the test use terrain as enforcers use it?
Enforcers are ambush experts. They hide behind a hill
or a bridge abutment, using that obstruction to block
your detector’s view of the beam until you’re up close
and within range. Then, as you pop into the full brightness of the
beam, zap!
you’ve been read.
To
defend, a detector must find radar before
the bright part of the beam is in full view. If it can’t find the glow behind the hill, it can’t
warn you. To see the benefit of a high-performance detector
like V1, a test must be set up like a real radar trap:
How much warning do you get from just the glow beyond
the hill?
B: Does the test try detectors
against Instant On radar? Some detectors, to avoid false alarms, ignore short,
weak signals. Which
means they ignore weak Instant On radar too. You don’t want to find that out after
you buy.
C: Does the test try detectors
against moving radar approaching from the rear? A number of moving radars (Stalker Dual DSR, MPH Python
Series II FS, Kustom
Golden Eagle and some Kustom Talon models) have a same-lane,
same-direction feature used every day to nab drivers from
behind. What
warnings will the detectors provide against those threats?
D: Does the test use a variety
of radar guns, particularly on Ka band? Ka band extends from 33.4 to 36.0 GHz, ten times
the bandwidth of X and K bands put together. Different Ka guns operate on different frequencies
within that wide band. How well does each detector perform against
all Ka guns?
E: Does the test include
photo radar? Most photo radars operate on Ka band, but there
are exceptions. Unlike ordinary radar traps, which use
terrain to stay out of sight, photo radar usually operates
out in the open. Instead of hiding, it minimizes detection range
by using a low-power beam angled across the road. So warning range is short, too short if you have
a weak detector. Because photo radar works out in the open, it should
be tested that way too.
The
bottom line:
- Do
the testers convince you that the
test detectors are typical of what you
could buy?
- Do
their procedures eliminate spurious interferences
from traffic and from biased personnel?
- Do
the tests simulate real traps you’ll
face?
If
you can say yes to all these questions, the test should
be a helpful guide to the state of the detector art.
|
Report
#6:
Laser Detectors Tests… sloppy methods bring worthless results.
Here’s what you should know.
|