Radio:
The radio, otherwise known as the transmitter or controller, is as important or more important than a helicopter. But what do you look for in a new radio, and why is a computerized radio such a good investment?
This page is all about a new R/C radio; controllers that come with most lower quality RTF aircraft are not generally going to be discussed, as usually they are very basic and not anything that you would want to buy separately, except to replace a broken or missing controller.
First off, what is a computerized radio? As can be seen from the picture of the Spektrum DX6i to the left, a computerized radio is basically a radio with a computer that allows the user to program specific values for the chosen helicopter. It needs to have a screen and at least one button (although higher end ones generally have several) for scrolling through lists and selecting. Please note, by button I do not mean switches, such as throttle hold and aux.
This page is all about a new R/C radio; controllers that come with most lower quality RTF aircraft are not generally going to be discussed, as usually they are very basic and not anything that you would want to buy separately, except to replace a broken or missing controller.
First off, what is a computerized radio? As can be seen from the picture of the Spektrum DX6i to the left, a computerized radio is basically a radio with a computer that allows the user to program specific values for the chosen helicopter. It needs to have a screen and at least one button (although higher end ones generally have several) for scrolling through lists and selecting. Please note, by button I do not mean switches, such as throttle hold and aux.
What can a computerized Radio do?
As mentioned above, computerized radios allow programing features for heli functions. In general, all computerized RC Heli Radios have (or should have to be worth more $$) throttle curve, pitch curve, dual rate, and exponential (EXPO) programming. Any computerized radio without one of these (except exponential, in my opinion) is not the kind of radio you want to invest in.
But what constitutes a great radio and how is it distinguished from a mediocre one? That all depends on its Brand / quality, features, and curve programming precision.
But what constitutes a great radio and how is it distinguished from a mediocre one? That all depends on its Brand / quality, features, and curve programming precision.
Brand / Quality:
In general, this shouldn't be too hard to understand; you don't want to spend good money on a piece of junk. Therefore, don't get a radio that is rated poorly on places like Amazon or Google! The best brands that I've come across are Spektrum, JR, Hitec, Airtronics, and Futaba. Other than these listed here, I would not buy a radio from any other brand because likely it is not very good quality. The golden rule of buying a radio is, do not go with a brand you don't like! Radio brand, once selected, is the least likely aspect of your RC experience that will change.
An almost unneeded note here is do not buy an IR controller! They are junk unless you are buying a replacement for a small IR coaxial. I don't know of any computerized IR controllers, but I thought I should mention it, just in case.
An almost unneeded note here is do not buy an IR controller! They are junk unless you are buying a replacement for a small IR coaxial. I don't know of any computerized IR controllers, but I thought I should mention it, just in case.
Features:
Aside from Brand / Quality, the Features of an RC Radio are the biggest selling points, as well as the biggest items to consider. The most common features are:
Now obviously not all of these features are needed. Many are just nice things that you can totally live without. If you are just getting a computerized radio, you can save yourself a lot of money by going for an entry-level radio without such nice extras as, say, an LCD screen or 4 pitch / throttle curves.
- Screen Lighting: Whether or not the screen has an LCD / other backlight.
- Programmable Dual Rates: Should be present on all computerized radios. Read what they are here. There should be dual rates for 3 channels from 1-100%
- Exponential Rates: Again, most all computerized radios have EXPO. It should be customizable from 1-100%.
- Number of Throttle Curves: Most entry-level computerized radios come with 2, normal and stunt, as well as a single input throttle hold line for a total of 3. The higher end / more channels you get, the more throttle curves tend to come with the radio. More throttle curves allows more types of flying styles such as gentle, scale, 3D, V-shaped, and extreme 3D. Flying types on all computerized radios are adjusted with the Flight Mode Toggle.
- Number of Pitch Curves: Most entry-level computerized radios come with 3: normal, stunt, and throttle hold. Again, the higher end / more channels, the more pitch curves and more flying styles. Each pitch curve corresponds to a certain throttle curve. The throttle / pitch combination is selected with the Flight Mode Switch on all computerized radios.
- Number of Channels: Computerized Radios generally all have 6 or more channels. More channels above 6 generally equates to more throttle / pitch curves and more curve programming precision (see below).
- Timer: Whether or not pushing / pulling a programmed button or switch will enable an on screen timer to give a general guideline of how long to fly on each battery.
- Neck Strap Hook:
Whether or not the radio has a hook to attach a strap that goes around
the wearer's neck to hold the radio. This makes dropping the radio and
breaking it much less likely.
- Charging Jack: Whether or not the Tx batteries can be charged while in the controller through a charger cable.
- Throttle / Pitch Curve Graphs:
Whether or not the throttle and pitch curves are represented
graphically. I highly recommend this feature on any computerized radio
you get, it makes it much easier to understand your throttle and pitch
programming.
- Sub Trim: Whether or not you can electronically change the centering of each servo.
- Reversing: Whether or not individual channels can be reversed.
- Mixing:
Whether or not the input of one channel can control the input of
another. This is generally only used on airplanes for rudder / aileron
mixing and generally should be avoided on RC Helis. This also includes
swashplate mixing to enable 120 or 140 Degree Swashplates to be accurately controlled.
- Number of Programed Models in Memory:
How many different aircraft the Radio memory will hold. You have to
program in all the values for that aircraft, but then next time you
want to fly it you simply select the model from the Radio memory and it
flies. In effect, you only need one radio for all your aircraft.
Believe me, I can say from experience that this is an almost must-have
feature. It saves every setting, including trim, for each model
separately. Entry Level Radios generally have around 10 spots, but
higher end / channel radios have 30 or more.
- Model Match: Whether or not the Radio will automatically recognize if the model selected from the memory is the same as the model "bound" to the controller. For Radios with Model Match, the radio will not allow you, say, to fly an airplane or even another heli of the same brand if it is not the helicopter currently selected. This prevents crashing in the first few moments from trying to fly something with the wrong settings.
- Radio Type:
PCM or 2.4GHz. I would not recommend anything but 2.4GHz radios today,
because they are much more immune to frequency clashes. Plus, there are
almost no computerized radios out there anymore that are PCM. Stay away
from PCM computerized radios even if they are nice and cheap, chances
are you'll find out that they weren't worth the money when you get a frequency glitch and crash.
- Swashplate settings: What type of swashplates are allowed by the radio. Most radios only allow two types, 90 Degree and 120 CCPM, but some newer higher end radios allow 140 Degree CCPM swashplates.
- Travel Adjustment: This allows placing a restriction on the distance that each servo / group of servos can travel. For example, setting pitch to 75% travel restricts that servo to traveling only 75% of its total distance, reducing all other inputs proportionately. Thus, it is almost identical to dual rates, except it has no toggles and it's used to keep a servo from over-traveling it's maximum distance or working too hard.
Now obviously not all of these features are needed. Many are just nice things that you can totally live without. If you are just getting a computerized radio, you can save yourself a lot of money by going for an entry-level radio without such nice extras as, say, an LCD screen or 4 pitch / throttle curves.
Curve Programming Precision:
The final distinguishing factor between radios is how many programmable points it has in its throttle and pitch curves. This is largely channel dependent; most entry level radios have 5 points. Anything less than 5 I would recommend staying away from; it will produce a vague throttle / collective feel. With more channels, this number of points is increased to allow much smoother and more precise throttle and pitch control.
This is where you can save some money, at least when starting out: get a radio with only 5 point curves. This will cut off hundreds of dollars when getting your first CP Heli. No question, more precise curves are nice and after you have them, you'll probably think programming with only 5 points is choppy. But when forced between the choice of a larger / higher quality helicopter with an entry level radio and a smaller / lower quality helicopter with a higher end radio (a choice the majority of us do have to face), hands down I would choose the better chopper and entry level quality radio.
This is where you can save some money, at least when starting out: get a radio with only 5 point curves. This will cut off hundreds of dollars when getting your first CP Heli. No question, more precise curves are nice and after you have them, you'll probably think programming with only 5 points is choppy. But when forced between the choice of a larger / higher quality helicopter with an entry level radio and a smaller / lower quality helicopter with a higher end radio (a choice the majority of us do have to face), hands down I would choose the better chopper and entry level quality radio.