Receiver Power Supply; The System In Use; Expanding The Transmitter; Expansion Facilities - FUTABA F-14 Instruction Manual

Receiver power supply

All Futaba receivers continue to work at full range even when
the power supply voltage falls to 3 V. The advantage of this fea-
ture is that the receiving system will normally continue to work
even if one battery cell fails (short-circuit), as Futaba servos
also still work down to 3.6 V; they just work more slowly and
with lower power. This can be very important in Winter when
outdoor temperatures are low, as the system will still work
when battery voltage collapses for brief periods.
However, there is a drawback to this flexibility: it is possible that
the battery will „lose" one cell and you will not even notice that
there is a problem. To avoid this danger it is important to check
the receiver battery from time to time.

The system in use

Always switch the transmitter on first, then the receiver, and
reverse the procedure when switching off. When you switch
on the transmitter the servos will run to the neutral position.
We recommend that you check each function individually by
moving the corresponding transmitter stick or associated con-
trol. Check also that the control surfaces on the model work in
the correct direction. If any system works the wrong way round
(e.g. left stick = right rudder), reverse that channel as described
earlier.
All servos must be free to work over their full angular travel wi-
thout any hint of mechanical obstruction by the control surface
or the linkage. This is particularly important with regard to the
carburettor linkage. The settings „full throttle" and „idle" must
be determined by the stick positions, and not by the mecha-
nical throttle stop or other obstruction. If this is not the case
and the servo is stalled, the servo motor will be under full load
virtually constantly, and this will drain the receiver battery dan-
gerously quickly.
As a basic rule the control linkages and control surfaces must
be installed and set up in such a way that they move smoothly
and with complete freedom. If the linkages are stiff, the servos
have to „work harder", current drain rises and the operating
time of the receiver battery will be much reduced. At the same
time the control surfaces will not centre accurately, and this
makes the model much more difficult to fly smoothly.
If any radio control system is to work reliably it is very important
to avoid what is known as electrical „noise". This can occur, for
example, when metal parts such as metal pushrods are allo-
wed to rub against each other under the action of motor vibrati-
on. For this reason the linkage to the carburettor should always
terminate in a plastic clevis, as a metal link will rattle against
the metal carburettor arm. If a metal clevis is unavoidable, in-
sulate the carburettor arm to avoid the metal-to-metal contact.
All electric motors in a model must be suppressed effectively,
otherwise the sparking which occurs between armature and
carbon brushes produces powerful interference which can pre-
vent the receiver working altogether. We recommend suppres-
sor filters or a set of suppressor capacitors. Each motor must
be suppressed individually.
100 nF
INSTRUCTION MANUAL
100 nF
47 nF
Fig. 15
F-14
Fig. 15 shows a typical suppression arrangement of an electric
motor.
Always extend the transmitter aerial fully before you start using
the system to control a model. When operating your model do
not point the transmitter aerial straight at it, as the radiated
power of the transmitter aerial is at its lowest in this direction.
It is best to stand with the aerial at right-angles to the model.
When several radio control systems are in use at the same
time, especially when they are on adjacent channels, the ope-
rators should always stand together in a loose group. Pilots
who insist on standing off to one side endanger both their own
model and the models of other pilots.
For safety's sake always carry out a full range check before the
first flight of a new model. This is the procedure: collapse the
transmitter aerial completely and walk away from the model.
At a range of about 60 metres the receiving system should still
work without any signs of errors or glitching.
With powered models repeat the range check with the motor
running, in case there are vibration problems or interference
from the electric motor. On no account try a flight if you are not
sure that all is well; seek out and eliminate the problem rather
than risk your valuable model.

4. EXPANDING THE TRANSMITTER

Expansion facilities

One of the outstanding features of the F-14 transmitter is that
a very comprehensive range of accessories is available which
can be fitted at any time. For example, the F-14 is the per-
fect basis for a special-purpose radio control system for model
boats.
1. Linear proportional channel
This slider control has a centre detent and expands the F-14
transmitter by one proportional function. We recommend that
it should be connected to one of the pin rows 5 - 8. The direc-
tion of servo rotation can be reversed by turning the connector
through 180°. The position of the pin row is shown in Fig. 5.
Fig. 16 shows a proportional slider unit.
The F-14 transmitter features two installation wells located be-
low the meter, designed to take one proportional channel each.
To install a slider you must first remove one of the covers in the
centre of the transmitter. To do this lift the corner of the alumi-
nium plate with a sharp knife and lift it off.
The slider unit can then be fitted in the transmitter from the in-
side and screwed in place on the front. The new cover can then
be carefully applied and the knob pushed into place.
3. 3-position switched channel
This switch expands the F-14 transmitter by one switched func-
tion, in this case the associated servo can take up any of the
following positions: left end-stop, centre, right end-stop. The
switch can be connected to any of the pin rows 5 - 8. The di-
rection of servo rotation can be reversed by turning the plug
through 180°. The position of the pin row is shown in Fig. 5.
Fig. 17 shows a three-position switched channel.
The F-14 transmitter can accept up to four switched channels.
To install a switch in option wells 1 - 2 you must first remove
Fig. 16
8
Fig. 17