| Re:< Note 428.0 by WRASSE::FRIEDRICHS "Jeff Friedrichs 381-1116" >
I would strongly recommend going 4 channel for the
following reasons:
Everybody needs a simple plane. We all have days where
our nerves are frayed for some reason or other and the best thing
it to take a simple plane up there and just putter around to get
relaxed. You only need more than 4 channels for craft that have
flaps, retracts etc. These are not right for put-put'ing around.
It's a bad idea to have many planes on a single
transmitter. If your frequency is busy, you are dead. A flight
back is only marginally cheaper than the complete package with
transmitter.
I normally take 3 planes to the field. All on different
frequencies. My radios are 4, 5 and 7 channels.
Anker
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| I'm the cub Jeff referred to --- competent in engineering in general
including [military] avionics, but an absolute novice in modeling RC.
I used to be a pilot, but Jeff says that's a handicap.
Comments on Anker's response (and I do appreciate such responses):
>> Everybody needs a simple plane. ... only need ... 4 channels
I agree that only a few channels are needed during early learning.
There does seem to be some disagreement in these notes as to 3 or 4
channels, but Jeff will be my instructor, so the initial plane will be
a PT-40 using 3 channels. Even if the decision is for seven channel
electronics, the old favorite (i.e. only) *plane* will be simple.
Now, am I missing something? I assume that extra electronics can be
ignored. Is it a problem to have these extra functions latent in the
equipment?
>> to have many planes on a single transmitter. .....
>> A flight pack is only marginally cheaper than the complete package
Valid points. Hmmmmn.
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| Re: .-1,
My advice has always been to buy all the radio you can afford up-front.
Be assured that you "will" want to go to full-house (4-functions)
one day so a minimum of 4-channels should be purchased. If you
start out with a 3-ch. rig and then want to add ailerons, yer' faced
with having to dispose of the 3-ch. radio (and, believe me, you
can't get anything for it) and "then" buy at least a 4-ch. rig.
Why not save the [wasted] extra expense and start with a minimum 4-ch.
rig at the outset? If you don't anticipate "ever" needing 7-channels,
I'd still recommend going for a 5-channel set as you "may" want to
experiment with some added function/dimension once you have learned
to fly like flaps, retracts, bomb or parachute drop, aerial
photography, etc, ad infinitum. If nothing else, the multi-function
radios (5-channels and up) tend to hold much better resale value.
It's up to you but I believe you'll be well advised to buy at least
a 4-ch. and, preferrably, a 5-ch. radio right off the bat. You
are correct in the assumption that using less that the available
number of channels causes no problems whatsoever.
Adios, Al
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| Following up on a point made by Anker in note 428.1, I've done some
homework on prices, sizes, etc. of Futaba gear. In particular, the
homework is applicable to Futaba pattern systems of at least 4 channels
and costing less than $200 (mail-order) with NiCd's.
This data is probably old hat to most readers of this conference, but I
include it for the benefit of other beginners and for critical comments
by the savvy.
Within this domain Futaba has two product lines, two modulations, and
four possible sets of control channels. The domain excludes the eight
channel systems, the helicopter systems, and those with PCM modulation.
It does include the low cost "L" product line and the mid-range "G"
line. The only advantage of the "L" line is the inclusion of their
bottom-priced package, a four channel system with three servos. If the
"L" systems are upgraded to four servos and NiCd's, the price
differential pretty much disappears, so the data below is mostly for
the "G" series. The "G" systems also have provisions for trainer
cords.
The avionics of the Futaba standard packages are based on four
receivers and two servos. Actually, the servos may be identical except
for the connectors. For reasons not obvious, the FM systems use a
different connector between receiver and servo than the AM systems.
Since Futaba sells adapter cables, this would seem to have been a
technical mistake now perpetuated for compatibility and/or marketing
reasons. The data below is based on packages with four S48 or S148
servos.
The four receivers are the AM receivers, the R4F (used in that entry
system), the R4H (that might be a nice glider item with much less
weight than the other receivers), and the R7H (used for over four
channels in for both product lines) and the FM receiver, the R107N.
The dimensions and weights of these receivers are:
R4F AM 1.56 x 2.27 x 0.75 1.6 oz
R4H AM 1.24 x 2.00 x 0.75 1.0 oz
R7H AM 1.56 x 2.68 x 0.78 1.9 oz
R107N FM 1.37 x 2.44 x 0.81 1.4 oz
In the eyes of a novice, these dimensions are all close to one another.
The weight differences might be significant if the battery weights are
comparable. Except for that, I conclude that there are no significant
mechanical factors on which to base a choice of avionics.
From the current Tower bi-monthly flier, we have the following system
prices:
"G" AM systems without dual rates:
4FG $145 (price from annual catalog and probably high)
6FG/AM $160 ( " " " " " " " )
"G" AM systems with dual rates on at least two channels:
5FGK/AM $165
6FGK/AM $170
7FGK/AM $185
"G" FM systems with dual rates on at least two channels:
5FGK/FM $177
6FGK/FM $185
7FGK/FM $200
6NLK/AM $180 "L" system but with NiCd's, no trainer
The seven channel systems have a few features lacking in the others:
three channels with dual rates instead of only two, mixing on two
channels, and something called ATV, whatever that is, on three.
One of the possibilities that had been considered was to buy first a
complete system then to buy only the avionics for the next plane. That
is not a winner. From Tower the add-on or replacement receivers cost
$69 for a four channel (don't know which), $94 for an AM seven, and
$110 for the FM seven. The servos implicit above are $19 each, so four
channels (implemented) plus receiver will amount to $145, $170, or
$186, depending upon the configuration --- and that doesn't include the
NiCd's, servo trays, etc. It is actually less expensive to buy the
complete system and discard the transmitter if so inclined.
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