4
V 2.0 Revised 09-03-2014
4) Failsafe
System
When the receiver is switched on, it will not output any channel position pulses until a radio signal is first
received. If the radio signal is subsequently lost, the receiver will continue to output channel pulses, but
their positions will revert to neutral. In the case of the throttle, the position will revert to minimum, which
means
minimum pulse width.
This will cause the vast majority of electronic motor speed controllers to go
to zero output. For glow-powered models, it is important to arrange the servo mechanics so that minimum
throttle corresponds to minimum control pulse width;
do not
use the throttle reverse switch in such cases,
otherwise the throttle will go to maximum in the event of failsafe activation. Please note that the receiver
does not learn new failsafe positions during binding – the failsafe positions are fixed.
Always test the
failsafe behaviour carefully after setting up a model.
5) Transmitter Mode Conversion
Changing from Mode 2 to Mode 1 is a two-step process. Firstly a switch is used to make the electrical
change, swapping the throttle and elevator controls to the opposite sides. Secondly, the elevator return
spring (together with the associated spring-return lever) and the throttle ratchet spring must be swapped
over, so that the new elevator control self-centres and the new throttle control has a “notched” feel.
To make these changes, the back of the transmitter must be removed by releasing its four screws. The back
section is connected to the front by a number of wires, so it should be folded downwards and placed on the
table in front of the main section. The photo below shows the location of the parts – the operations are self-
explanatory. A pair of fine tweezers will be very helpful for manipulating the return spring.
6)
Specifications
Snelflight Ltd, 48 Chalfont Way, Meadowfield, DH7 8XA, United Kingdom.
Web:
www.snelflight.co.uk
Email:
Transmitter T4EU
Channels
5
Transmitting frequency
2.4GHz
Modulation type
FHSS
Nominal current drain
100mA
Power supply
8 x AA battery
Output power
10mW
Channel centres
1.5ms
Receiver R7F
Channels
7
Receiving frequency
2.4GHz
Power supply
4.5 – 6.5V
Range
500
yards
ground
1000
yards
air
Weight
12g
Antenna length
8cm
Mode Switch
Throttle ratchet spring
Elevator centre spring
