Radio Control Terms and Definitions:
This page contains a brief rundown on common terms about Radio Control. Included on this page are:
- Remote Control
- Radio Control
- Infrared Control
- Controller
- Channel
- Proportional Control
- Receiver
- Frequency
- Dual Rate
- Remote Gyro Gain
Remote Control:
Remote control is anything which takes control movements from one device and transmits it to another. Basically, that's all there is to it.
Radio Control:
This is any remote control which uses as its medium radio waves. Generally, radio control is in the 25-75MHz frequency, but 2.4GHz radios have broken that trend.
For the purposes of this site, RC will mean R/C, which means Radio Control. However, most of the information on this site will apply just as well to Remote control in general.
R/C is generally the remote control medium of choice, because it has the longest range and usually offers beyond line of sight control (both behind obstacles and out of sight range).
For the purposes of this site, RC will mean R/C, which means Radio Control. However, most of the information on this site will apply just as well to Remote control in general.
R/C is generally the remote control medium of choice, because it has the longest range and usually offers beyond line of sight control (both behind obstacles and out of sight range).
Infrared Control:
Infrared (IR) control is a form of remote control that uses the infrared portion of the spectrum to send and receive commands. TV controllers are generally infrared, as are some mini indoor coaxial helis. The problem, or limitation, with infrared control is that it is strictly line of sight. The controller is basically shooting an invisible light beam (as infrared is near to visible light on the electromagnetic spectrum, unlike radio) to the receiver, and with something in the way this connection is interrupted. This is also why infrared cannot fly outside during the day; the sun's immense infrared light (or heat) washes out the small beam from the controller.
Never get a CP heli with IR control; you will more than likely be sorry. However, mini IR coaxials are fine, as it would take a dead calm day to fly them outside anyways. Just remember never to attempt to fly outside with them.
Never get a CP heli with IR control; you will more than likely be sorry. However, mini IR coaxials are fine, as it would take a dead calm day to fly them outside anyways. Just remember never to attempt to fly outside with them.
Controller / Radio / Transmitter / Tx
All these terms mean basically the same thing: the handheld device that interprets stick and switch movements and sends them to the receiver of the same frequency. Without a transmitter . . . there is no RC (IR or R/C).
Technically, an rc radio can be referred to as a controller, transmitter, or Tx, but these terms don't necessarily imply a radio; they can apply to an IR transmitter as well. For purposes of this site, however, these terms will be used interchangeably.
Technically, an rc radio can be referred to as a controller, transmitter, or Tx, but these terms don't necessarily imply a radio; they can apply to an IR transmitter as well. For purposes of this site, however, these terms will be used interchangeably.
Channel:
In the RC world, the number of channels is important, especially for helicopters. Each channel equates to one function, whether it is throttle, forward / backwards movement, or even retractable landing gear. Here is a general breakdown of channel allocation on an RC helicopter:
2-Channel: Throttle and Yaw (Rudder) Control
3-Channel: Add Pitch (Elevator) Control
4-Channel: Add Roll (Aileron) Control
5 and 6 Channel: Add Collective Pitch and remote gyro gain (see below)
As far as I know, there are not 5 channel recievers; basically if you have collective pitch, then your reciever is 6 channels.
7+ Channel and optional Add-Ons: These are functions that can be added to enhance the repertoire of a helicopter with any number of channels. Examples include retractable landing gear, triggers for laser tag, changing lights, etc.
The number of channels is determined by both the vehicle and the controller. Thus, if you have a 5 channel heli with a 3 channel controller or vice versa, you will only be able to use the maximum number of channels common with both: in this case, only three.
2-Channel: Throttle and Yaw (Rudder) Control
3-Channel: Add Pitch (Elevator) Control
4-Channel: Add Roll (Aileron) Control
5 and 6 Channel: Add Collective Pitch and remote gyro gain (see below)
As far as I know, there are not 5 channel recievers; basically if you have collective pitch, then your reciever is 6 channels.
7+ Channel and optional Add-Ons: These are functions that can be added to enhance the repertoire of a helicopter with any number of channels. Examples include retractable landing gear, triggers for laser tag, changing lights, etc.
The number of channels is determined by both the vehicle and the controller. Thus, if you have a 5 channel heli with a 3 channel controller or vice versa, you will only be able to use the maximum number of channels common with both: in this case, only three.
Proportional Control:
Having proportional control on a channel means that for each small change on the controller, a corresponding change is initiated on the vehicle in the same proportion. For example, a small change in throttle relates to a small change in engine speed, whereas a large change in forward control equates to a large change in forward speed. In essence, each channel has an almost infinite number of "buttons" equating to a different speed or position for that motor or servo. All helicopters (except perhaps toy 2-channels or less) have proportional control on all movement channels.
However, low-end RC cars, boats, etc typically don't have proportional control; in other words, there are only two buttons for each channel. A car without proportional control would have one "button" for forward movement and one for backwards.
For each channel with proportional control, there will be a little slider next to and parallel to the movement of the channel on that stick. This is that channel's trim. For non computerized radios, the trim slider for each channel will be able to move and stay in any location desired. Trim on computerized radios is generally stored in the computer, so each "click" in one direction corresponds to a small movement of the electronic slider in that direction.
An important point is that proportional control is determined by the controller and the vehicle / reciever. If I'm wrong about this, which I could possibly be, then please tell me :)
However, low-end RC cars, boats, etc typically don't have proportional control; in other words, there are only two buttons for each channel. A car without proportional control would have one "button" for forward movement and one for backwards.
For each channel with proportional control, there will be a little slider next to and parallel to the movement of the channel on that stick. This is that channel's trim. For non computerized radios, the trim slider for each channel will be able to move and stay in any location desired. Trim on computerized radios is generally stored in the computer, so each "click" in one direction corresponds to a small movement of the electronic slider in that direction.
An important point is that proportional control is determined by the controller and the vehicle / reciever. If I'm wrong about this, which I could possibly be, then please tell me :)
Receiver / Rx:
The receiver is the device attached to the heli that receives (through an antenna on R/C) and interprets the commands sent from the controller. It then translates the electrical commands back into mechanical movement, such as of the swashplate, motor, etc. On smaller helis, the receiver is generally wired into the control board (such as with a coil), but on larger helis, there will be a dedicated receiver, such as the one shown to the side.
With a dedicated receiver, the functions of the helicopter are all plugged in to the receiver. In this case, each servo has its own assigned channel, with the motor plugging in to the ESC, which plugs into the throttle outlet.
With a dedicated receiver, the functions of the helicopter are all plugged in to the receiver. In this case, each servo has its own assigned channel, with the motor plugging in to the ESC, which plugs into the throttle outlet.
Frequency:
The frequency of a controller / receiver basically equates to the number of times the signal completes one wave a second. The higher the frequency, the more electromagnetic waves a second and the higher the energy of the signal. On R/C vehicles, the frequency is generally 25-75MHz or 2.4GHz - a higher energy frequency.
Basically, unless your heli has a separate receiver, you can't change the frequency of the heli. Unless of course you try to tune the coil on your control board, which allows a small change in frequency (a whole huge subject on its own - I've done it, but I've never been able to stretch far enough to allow a change in radios). On radios, too, you can't change the frequency unless you replace the crystal with a new one - also outside the scope of this site :)
Basically, unless your heli has a separate receiver, you can't change the frequency of the heli. Unless of course you try to tune the coil on your control board, which allows a small change in frequency (a whole huge subject on its own - I've done it, but I've never been able to stretch far enough to allow a change in radios). On radios, too, you can't change the frequency unless you replace the crystal with a new one - also outside the scope of this site :)
Wavelength:
Wavelength is related to frequency by the formula c/f, where c is the speed of light (299,792,458 m / s, or
983 571 056 feet / second) and f is the frequency in Hz. Thus, the wavelength of a 27 MHz frequency is about 36.5 feet (11.1m), the wavelength of a 40MHz frequency is about 24.5 feet (7.5m), a 49MHz frequency has wavelength of about 20 feet (6.1m), and 2.4 GHz has a wavelength of about 5 inches (12.5cm). This is the optimum antenna length; however, as is probably obvious, none except perhaps 2.4 GHz systems attempt to meet this length. However, the closer an antenna is to this length, the better the range.
983 571 056 feet / second) and f is the frequency in Hz. Thus, the wavelength of a 27 MHz frequency is about 36.5 feet (11.1m), the wavelength of a 40MHz frequency is about 24.5 feet (7.5m), a 49MHz frequency has wavelength of about 20 feet (6.1m), and 2.4 GHz has a wavelength of about 5 inches (12.5cm). This is the optimum antenna length; however, as is probably obvious, none except perhaps 2.4 GHz systems attempt to meet this length. However, the closer an antenna is to this length, the better the range.
Dual Rates:
Dual rates are the percent movement of a channel the servo for that channel can make. For example, 70% dual rate means each movement on that channel causes 70% of the movement expected if the channel were at 100% dual rate. Thus, moving the stick 10% on a channel at 50% dual rate would cause the helicopter servo to move 5% (because 10% of 50% = 5%). Dual Rates are always expressed as a percent.
Dual Rates are used to "tame down" helicopters, especially collective pitch ones, to respond less to the large inputs typical to beginner pilots. There are usually only dual rates on rudder, elevator, and aileron (click here to learn what these three terms mean). For more information about what dual rates to use when learning to fly a CP Helicopter, go to Collective Pitch Flight School Lesson 2.
Dual Rates are used to "tame down" helicopters, especially collective pitch ones, to respond less to the large inputs typical to beginner pilots. There are usually only dual rates on rudder, elevator, and aileron (click here to learn what these three terms mean). For more information about what dual rates to use when learning to fly a CP Helicopter, go to Collective Pitch Flight School Lesson 2.
Remote Gyro Gain:
Remote Gyro Gain is basically a toggle assigned to switch the "gain" or sensitivity of the tail gyro. If you are anything but a very advanced flier, don't mess with this. This feature is used to adjust the sensitivity of the gyro at different main rotor rpms. This is generally not something most people need to worry about, but it's there.
Of note is that if you have a HH Gyro, messing with these feature will reduce the quality of your tail hold. HH Gyros have better tail lock than the best gyro gain settings. If you have a HH Gyro Helicopter, inhibit this function on your radio.
Of note is that if you have a HH Gyro, messing with these feature will reduce the quality of your tail hold. HH Gyros have better tail lock than the best gyro gain settings. If you have a HH Gyro Helicopter, inhibit this function on your radio.