| I've been trying to get across to people that there's absolutely no
| reason on earth why anyone should spend good money on a 20th century
| receiver when 21st-century technology is now readily available at what
| is often a lower price.
Of course, what you say is 21st century technology actually came out
of the 20th century, but I digress ...
| That companies like Hitec continue to sell "dumb" PPM receivers to an
| unsuspecting public is little short of outrageous!
| A Hitec 555 costs around US$53 plus $8 for a crystal. The smaller,
| lighter, and far more interference resistant Berg or FMA receiver
| costs just $50 *with*
a crystal and provides far more protection
| against being shot down.
I certainly like my FMA M5s (about half of my planes have them now),
and I like the price, and I do like their glitch rejection, but I'm
not acting under the deluded impression that they provide `far more
protection against being shot down'.
They will handle temporary glitches much better, basically ignoring
them. Longer glitches, and they'll just say put rather than having
the servo bounce all over the place. But they don't provide that much
protection against being shot down. If somebody else turns on their
transmitter near you, and their signal is stronger than yours at the
plane, your plane is going to crash -- I don't care how smart your
Even those receivers that claim to respond only to YOUR transmitter
(which smells of snake oil to begin with) and not going to save your
plane in that instance.
| With modern models weighing more and flying faster than their
| predecessors, and with the RF spectrum becoming increasingly crowded,
| I seriously wonder whether the sale of new dumb PPM receivers ought
| not to be outlawed.
Just what we need ... more laws.
Did you know they still sell AM receivers too? And things like the
Hitec Feather are even worse than the receivers you're referring to.
| No doubt many people will say "but I fly with a Hitec (or other dumb
| receiver) and have never had any problems with glitches or
| interference) -- but trust me, it's only a matter of time before
| someone in the pits shoots you down or some random burst of noise hits
| your model just a you're lining up on final approach or takeoff.
... not that your FMA or Berg or even PCM receiver is going to save
you from this reliably. It might help if the noise lasts a very short
time, but only then.
| Few modellers are prepared to fly without public liability insurance
I wouldn't say that. Certainly, many park fliers are flown by people
with no liability insurance.
| -- but let's not forget that updating your receiver to one that can
| reject interference and provide a failsafe capability is also an
| extremely valuable piece of insurance against needing to make a claim
| on your liability policy.
And none of the PPM receivers that you've mentioned have failsafes at
all. At best, if they can't pick up a signal anymore, they just stay
where they were. Which is good, but not ideal.
What we really need is spread spectrum radio equipment. That won't
make all the interference issues go away at once, but it will
certainly remove the largest problem immediately -- that of another
modeler turning on his transmitter on the same frequency as yours.
But there's political (not technical) issues that need to be overcome,
and I've gone into them before so I won't do so again now.
Doug McLaren, email@example.com
We came. We saw. We kicked its ass." -- Bill Murray, _Ghostbusters_
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