Thursday, March 19, 2020

Which surface radio is the best?

There is no single radio system that is going to be "The Best" for everyone, but I will do my best to break down some features to help you decide which system has the potential to be "The Best For You" based on your own requirements.

Before you even begin selecting a system, I feel that it's very important to understand the technologies/features that are available and then you can begin ruling on which points are the most important as you begin your search. I've ordered each option by level of personal importance to me:

Which Spread Spectrum Modulation?
If you will be driving all by yourself, then this consideration is probably irrelevant, however, if you will be using your system in a large group with other radio systems present (i.e. Club Racing) then there is a risk of overlapping frequencies and/or limited range issues with your system which can cause severe delays in the input/response, this is called "Glitching". I have experienced varying levels of glitching with every single system that I have personally tested which use DSSS or "Direct Sequencing Spread Spectrum". Basically any system that has the letter "D" anywhere in the identification of the type of modulation. For example:
  • FlySky = AFHDS, AFHDS-2A
  • Spektrum = DSM, DSM2, DSMR
  • Radiopost = SDS, SDSTM (went out of business around 2018)
For a noisy environment, FHSS offers a better option to mitigate any risks of glitching, more specific details are explained here:
http://www.rcmodelreviews.com/spreadspectrum01.shtml
and here:
DSM/DSSS vs. FHSS 2.4GHz Modulations - FASST explained as well (9 min 53 sec)


  • I personally feel more comfortable recommending a system that uses FHSS and caution to stay away from any system that uses any flavor of DSSS just to play it safe.
  • HiTEC ditched DSSS (Aggressor series) and have since switched to using FHSS with the latest release of their Lynx 4S... Kudos to HiTEC for meeting the consumer's needs!
  • GFSK is a newer flavor of FHSS.
  • AFHD3 - Newest from Fly Sky NB4 which has fixed all known issues from it's predecessors, dozens of racers use this system in my are (myself included) without any glitching!


Telemetry
The use of telemetry is generally prohibited in almost all levels of organized racing, so be careful not to get suckered into having this set of features as you may risk being disqualified if you get caught using them at a racing venue. On the flip side, if you are just bashing around or would like to quickly check your temps for tuning purposes, then it can be handy to have an alarm sound if your electronics get too hot. Other important telemetry features include on-board voltage readings as well as speed sensors.

*** There have been complaints against Spektrum for limited effective range of telemetry readings being around 30' from the Tx

Features
  • How many model memories do you need?
  • How expensive are spare Rx's?
  • Does it include steering speed? Many low end systems do not include this feature which is the single most important feature to me!
  • How many characters do you need in your model names, and how long do the names need to be?
  • How fast/precise/smooth is the radio?
  • Is the screen large enough and easy to read in direct sunlight?
  • Are dual rates adjustable for each channel direction?
  • Are exponential rates available?
  • Is there a timer/stopwatch/alarm integrated?
  • How many channels do you need and/or mixing?
  • Does it include a fail safe?
  • Does it include a DSC port for simulator racing with VRC?
  • Does it accept rechargeable batteries and if so is there an external charger port?
  • Does the Rx accept HV?

Ergonomics
 - "Ergos"

  • How comfortable is the radio to hold?
  • What adjustments (if any) can be made to make the radio more comfortable?
  • Can the spring tension be adjusted on the steering and throttle?
  • Can the trigger be adjusted so that it's closer to the grip for smaller hands?
  • Is there a drop down available for the steering wheel?
  • Can the steering wheel be rotated into various angles?
  • How heavy is the radio? Can lighter lithium batteries be installed?
  • Are there replacement grips and or any soft rubber parts that are interchangeable to help increase comfort?
  • Are there different size steering wheels available to accommodate smaller hands?
  • Are there quick trim buttons easily accessible from the steering wheel? 
    • Can you reasonably make trim adjustments without having to look at the radio, such that adjustments can be made during the middle of a race? 
      • It's common for a car to lose trim setting after a crash.

Integrated Gyro
Gyros provide counter steer to help improve corner tracking which is best suited for drifting and/or low traction conditions. They are typically not allowed in racing as they significantly improve the handling to prevent the car from spinning out on a tight corner.
  • Radiolink: 3rd channel adjustment effects steering input only
  • Spektrum: 3rd channel adjustment effects both steering and throttle equally with the DX2E, you can't mix control bias to remove effect from throttle without also removing effect from steering. The DX4/5 series allows independent gain adjustments
  • KO Propo: 3rd and 4th channels control steering and throttle gain independently giving full flexibility of the gyro across both channels
Customer Support
Almost all brands of radios are manufactured overseas, however a few "name brands" have distributors in the US who cater to sales of their radios within their channel to ensure the highest level of customer support is honored. Some distributors will scan the serial number for each radio and will refuse warranty to any radio that was not distributed through the US channel. Plan to ship your radio for service from the same distribution channel you purchased from. 


PriceBrandModelCHMMModulationTxVRRxVRChg
Port
Str
Spd
Ch
Mix
Rx
Cost
Notes
$21Hobby Porter91803G-VT31GFSK4.8-6V4.5-6V---$9Micro Size, Small grip
$21Dumbo RCX441FHSS (67CH)4.8-12V3.3-10VUSB-Y$123ms, Opt Gyro Rx, DSC
$31Dumbo RCX661FHSS (67CH)4.8-12V3.3-10VUSB-Y$123ms, Opt Gyro Rx, DSC
$37Fly SkyGT3B310AFHDS (16CH)9.5-12V4.5-6.5VYes--$922ms, DSC, Opt firmware/mixing
$41Dumbo RCX6P(w/LED)61FHSS (67CH)4.8-12V3.3-10VUSB-Y$123ms, Opt Gyro Rx, DSC
$45SpektrumSTX331FHSS4.8-6V3.5-9.6V---$151 yr waranty
$48Hobby PorterHP007715GFSK4.4-8.4V4.0-8.4V---$12Gyro,Tlmtry,Flashlite,Cruise Cntrl
$54Fly SkyGT3C310AFHDS (16CH)3.7-4.2V4.5-6.5VUSB--$922ms, DSC, Opt firmware/mixing
$55RadioLinkRC4GS410FHSS (16CH)4.8-15V4.8-10V-YY$1518ms,Gyro,DSC
$75RadioLinkRC6GS610FHSS (67CH)4.8-15V4.8-10V-YY$1512ms,Gyro,DSC
$76Futaba3PRKA31FHSS4.8-6V4.8-7.4V---$4014ms
$78DasmikroFS-GT3C860AFHDS (16CH)3.7-4.2V4.5-6.5VUSB-Y$922ms,DSC
$80TurboWingFPV+Cam21FHSS------FVP Display built into Tx
$100SanwaMX-6310FHSS-E4.0-9.6V4.8-7.4V---$49Waterproof Rx
$121Futaba3PV410S-FHSS4.2-7.2V4.8-7.4VYes-Y$40NiMh or LiFe only in Tx
$124Fly SkyIT4S420AFHDS2-160CH3.7-4.2V4.5-6.5VUSBYY$15Tlmtry, TouchScreen
$155SpektrumDX5C520DSMR4.8-6V3.5-9.6V-YY$8011ms,Gyro (AVC), Tlmtry
$186Fly SkyNB4420AFHD33.7-4.2V3.5-12VUSBYY$333ms, Tlmtry,Tension,LGrip,TouchScreen
$240KyoshoKT-432PT420FHSS-140CH4.2-6.0V4.0-6.5V-YY$18DSC,Tension,LGrip,TouchScreen
$230Futaba4PM440T-FHSS4.2-6.6V4.8-7.4VYesYY$65Tension,LGrip
$250GraupnerX-8E435FHSS3.4-6V3.6-8.4VUSBYY$32Tlmtry,Tension,LGrip,TouchScreen
$250SanwaMT-S420FHSS-44.8-7.4V4.8-7.4V-YY$100Tlmtry,Tension
$260HiTECLynx4S430AFHSS4.8-8.4V4.8-8.4VYesYY$284ms,Tlmtry,Tension,LGrip
$282KO PropoEX-2440FHSS4.0-8.4V4.8-8.4V-YY$62Tension,Gyro(Optional)
$300SpektrumDX5 Pro5250DSMR4.0-8.4V3.5-9.6V-YY$9011ms,Gyro (AVC), Tlmtry,Tension
$325SanwaMT-44420FH4T3.7-4.2V4.8-7.4V-YY$100Tlmtry,Tension
$400SanwaM12S450FH4T3.7-4.2V4.8-7.4V-YY$100Tlmtry,Tension
$530Futaba7PX740T-FHSS6.0-7.4V3.7-7.4VYesYY$80Tlmtry,Tension,LGrip,TouchScreen
$550SanwaM17450FH4T3.7-4.2V4.8-7.4V-YY$95Tlmtry,Tension, TouchScreen
$550SpektrumDX6R6250DSMR4.0-8.4V3.5-9.6V-YY$90Tlmtry,Tension,LGrip,TouchScreen
$600Futaba7PXR740T-FHSS6.0-7.4V3.7-7.4VYesYY$80Tlmtry,Tension,LGrip,TouchScreen

Here is some testing that I've done with some of my personal radios:


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