Product review: RADIOLINK RC4G radio transmitter

About

I think its about time for me give out my fair share review on something that i already had in my hands for almost 3 years of using it on ground R/C models and most importantly its the best stuff to have for ground FPV projects that you've been witnessing for all these years on my Youtube channel; its the RADIOLINK RC4G 2.4Ghz 4 channel radio controller. If you have been watching all my ground FPV video projects from fast driving buggy/trucks to roaring V8 4x4 models roaming at long ranges around various tracks and location i can say my FPV success contributed by the radio performance of RC4G radio transmitter. First here some background how i ended up with this R/C transmitter; somewhere in mid 2015 i was looking for a cheap budget transmitter at local hobby shop just to get 1:12 FEIYUE FY03 truck running for my next ground FPV project since the stock RTR radio and integrated electronics on FY03 got burned really hard. With $50USD budget in hand the only good popular controller i could reach out was the intermediate performance 2.4Ghz FLYSKY GT3B/C unit which is popular among R/C car modeler at that time so my choice was locked on went looking around at my friend's R/C shop. Since it was intended for FPV i didn't rely much with its 2.4Ghz radio but expected to piggy back my new 433Mhz DALRC QUHF radio transmitter module via relay its PPM signal port to the 433Mhz module through minor mods...so it means controlling my car/trucks using 433Mhz via FLYSKY controller with its 2.4Ghz radio disabled for extra range. So i got to my friends shop but FLYSKY was no where to be found sold out leaving only one radio left on top of the shelf i'm not familiar at which is the RADIOLINK priced at extremely cheap for exactly $50USD!. At that time i'm not really confident going out with something i'm not familiar with but knowing its cheap, has 4 Channel plus built-in steering gyro and will be gutted out for experimental 433Mhz mods i place my cash and went off to get my FPV project done. The next day my RC4G radio link was relayed to DALRC QUHF 433Mhz TX module which helps to transmit radio signal to its receiver onboard FY03 truck while the FPV vtx runs on TBS UNIFY 2.4Ghz 800mw unit, it went well for 700m~1000m range behind some trucks and containers around the port yard but i wasn't satisfied because the FPV visual was very rouchy around 500m and full of artifact probably due to UHF system got too close with 2.4Ghz or probably to close to 'Ground Level Noise' since 1:12 scale FY03 truck is way too small and short platform to get adequate ground RF clearance unlike popular 1:10 and 1:8 platform or how high towered TRAXXAS SUMMIT does it. So on second day i removed the QUHF TX module with its receiver from FY03 and directly put back the RadioLink RC4G's R4EH-G receiver back on and do some test range on our R/C flying club runway which got me approximately between 350~400m range with 5.8Ghz 600mw SKYZONE video transmitter still show clean FPV video but got range cut-off from RC4G. So i went back home thinking the radio itself need some boost planning to add 1000mw booster module which i originally bought for boosting 2.4Ghz signal intended for DJI radio unit. I disassembled the RC4G and access the inner PCB board located the FHSS radio transmitter module that was soldered on board until i discovered a hidden what i assume a radio 'boost' switch not far under the LCD display board. By default the switch are in 'NOR', i've decided to flick down to 'LARGE' mode and see what will happen on the next day FPV range test drive. Indeed during the FPV range test next day my FY03 manage to drive pass 400m till 700m and more gaining extra distance so i guess the 'LARGE' switch does amplify the radio frequency/or maybe wattage value....and that's how i ended up with RC4G for the rest of my ground FPV projects and also on normal R/C basher.



Specification (as describe by vendor/manufacturer)

Brand: RadioLink

Model: RC4G/ RC4GS (latest revision)

Size: RC4G radio- 213 x 117 x 115.5mm, R4FG receiver- 35x 20 x 13mm

Channel: 4

RC Model support: cars, boats (Ground or water based R/C models only)

Modulation mode: GFSK Spread spectrum FHSS

Model memory storage: 10 models memory storage

Antenna length: 106mm

Control distance: more than 400M (My test range: 450~700m >>)

LCD screen: 128*64 resolution, LCD back light

Power supply: 4.8-15.0V DC,4*AA or 2S-4S Lithium battery

RF power: <10dbm

Low voltage alert: yes( lower than 4.6V), can be set when using 2s-4s Li-Po battery

Frequency: 2.4Ghz ISM band (2400MHz-2483.5MHz)

Channel resolution: 4096

Work current: 80-120mA

Receiver: R4FG,R8EF,R8FM, R4EH-H and R4EH-G



Features: RC4GS with chip TICC2500,same FHSS 16 channels pseudo random frequency sequence hopping technology of AT9S Receiver with gyro integrated to hold the vehicle in a straight line during aggressive acceleration and braking or get bumped It take 12ms only for 4 channels to response parallel, better than the average time 20MS 4 channels mix programmable :AUX channel 3 & 4 can be slave controlled by channel 1or 2 , or operate individually to turn lights and open doors in boats or cars Fail safe can set up by yourself as you need Multiple battery support and anti-polarity connect protection intelligent :JST battery port, 4pcs AA batteries 1 parameters such EXP,IDLUP,D/R, THSPD and so on self setting A.B.S function for anti lock brake: do not slip as corners brake thus avoiding and program Upgrade firmware by a USB cable helps RC4GS always keeps the most advanced system and program

Package included:

1x Radiolink RC4GS Transmitter (RC4G for early 2015~2016)

1x R4FG-G gyro inside Receiver (R4EH-G for early 2015~2016)

1X Manual

Manual download:

RadioLink RC4G user manual: Download here

Pros: Affordable price at $60'ish range (by early 2018) with every feature needed for FPV projects.

Built-in steering gyro inside the R4EH-G receiver for uninterrupted straight line driving.

Very light controller and doesn't strained my arm holding for more than 30 minutes while using 3s Li-po battery to power the radio.

Cheap 4ch receiver under USD$10 including compatible/alternative set from different model or rebranded unit such as HobbyKing TRACKSTAR TS4G receiver

All channel are fully programmable, mixable and have max EPA throw unlike FLYSKY at almost the same price range.

FAILSAFE feature can be easily programmed into the receiver unit through the radio controller itself rather than pressing any button on the receiver unlike traditional failsafe procedure on standard receiver.

Receiver unit support input voltage 4.4~8.6V (2S)

Responsive control even driving far beyond line of sight especially FPV usage without any visual indication of control lag or delays. Cons: Early release RC4G radio model doesn't have USB port supported for firmware upgrades, only later model with extra 'S" signature at the back (RC4GS) has it.



Range and performance

After using it for more than 3 year i must say its definitely the best affordable R/C controller with all the basic need to grow collection of ground R/C from simple weekend R/C basher, track racing to FPV projects. Its has all the advance setup, advantages and goodies against rival FLYSKY GT3B/C or other pistol grip controller at the same price and most notably the radio coverage range is phenomenal. The LCD screen on RC4G is not as cheapish like what you see on FLYSKY at the same price range, it has standard dot matrix type screen and menu almost like SPEKTRUM like controller. EXPO setup are more refined and EPA have more 'throw' than FLYSKY GT3B/C rival. Its also has advance feature like Channel mixing, refine ABS setup with channel mixing for actuated braking during cornering pretty much similar feature you would find on expensive pro level radio controller like SANWA, FUTABA and KO-PROPO. The most impressive feature that i like the most are how easy it was to setup the 'Fail Safe' on all channel and also setting up Gyro steering feature. On traditional R/C radio unit fail safe usual setup by manually positioning the channel first then press a button (usually binding button) on the receiver to get it to work but on RC4G i just need to activate the fail safe via screen menu then just restart the car/truck model via ON/OFF or plug unplug the battery so that the fail safe setup are properly stored into receiver memory so it means more convenient than pressing or de-pressing the receiver's button when the receiver module are already deeply embedded permanently or inaccessible inside the model especially on my FPV model. Another one is about the build-in steering gyro feature which available on selected RadioLink ground receiver mostly have initial marking "-G" at the back of every receiver naming for example R4EH-G or R4F-G, The one i use a lot is the R4EH-G type but do aware that another compatible unit that works with RC4G radio is the Hobby King's TRACKSTAR TS4G V2 receiver which also an identical to R4EH-G (probably made by the same manufacturer) but with different label works well too. I owned 4x unit of TS4G receiver bind 100% well with my RC4G without any issues. The gyro unit mostly control the CH1 steering port in rate mode and the sensitivity can be tuned remotely from the controller itself via CH3 (VR) knob. The CH3 channel is mixable too, user may opt to have it enable or disable by pressing the button 3x times on the receiver or manually from the controller by reducing the rate to '0' value...you'll need to read the manual for that. There not much radio on the market that offer premium feature at a great price like what featured in RC4G unit, plus the receiver unit with gyro sensor costs below USD$9~$10 far cheaper than just buying stand alone receiver and gyro.

During operation the handling and control performance is very satisfying, no lag or delays in controlling the models even driving far distance in FPV view BLOS (Beyond Line Of Sight) behind trees and obstacles more than 500m >> and above as viewed from my FPV video goggle...fast enough reflex to hit the brake or avoid hitting obstacles at high speed even at far distance just as shown in many of my FPV video in my Youtube channel. The weight of the controller is a major plus for being very lightweight if to be powered by lighter Li-po battery, i don't feel cramp around my arm holding it in my hand for more than 30 minutes unlike my SANWA M11 and MX-A unit. FYI i'm using 3s 1500mah li-po to power the radio (11.1~12.4v).

FPV range tips

As mentioned before the stock transmitter is 100% FPV capable given you drive within or below 1000m but i have not yet proven if it could go beyond 1000m because our local club R/C flying runway have only 830m usable length to test it in line of sight just like how i used to test my FPV FY03 in previous run still within 500~700m with solid control is huge distance to roam around just for an FPV car/trucks. A quick note that be caution when driving around the public space because some nasty people might 'car'napped (kidnap) your car/trucks at that range just like what happened in our ground FPV forumer where his FPV TRAXXAS was picked up by stranger down the road as he drive far away beyond VLOS (Visual Line Of Sight). All you need to get full range radio signal is just flick the switch. To access the switch you will need to open the radio plastic casing but unscrew several screws from top to bottom, before you do this make sure you unplug any battery off from the radio unit. Once unscrewed gently open on the left side of the plastic case where most of the auxiliary plug, usb port and ON/OFF switches are located and search for the radio amplifying switch that is located on the top left corner behind the LCD display panel. The switch looks like small plastic DIP switched default in 'NOR' (NORMAL) position set by factory which give you stock range between 200m~300m, you can flick it down to 'LARGE' to amplify the radio power which give you average 500m~800m >> straight line. However the condition of the range can be varies depending if there's an obstacles between your radio and moving model which can deteriorate the radio penetration. Setting the switch to permanently 'LARGE' mode have no drawback in long term usage because i've been using it for almost 3 years without an issues but if you wanted to dodge FFC regulation during checkups you might with it back to 'NOR' mode.

Note that you don't have to drive that far to enjoy FPV because even 500m x 500m land size still felt really far and lots of place to explore, just don't accidentally crash into things, turn turtle or get stuck because even spent half its full range it can be tiring distance to walk over to retrieve your truck/car...i hate walking especially if i carry bulk FPV equipment and Li-po battery strapped around me.

Another important note that your radio range may varies depending on how you place the receiver antenna away from RF (Radio Frequency) noise onboard your models which encounter noisy RF from ESC/BEC, servo, OSD, VTX, motor and etc because these factor may dampen or reduce your receiver antenna sensitivity to receive radio signal from your RC4G transmitter so try to keep your receiver as far away from other RF emitting devices. You might notice that some of my FPV trucks have receiver and antenna located at far end of the chassis usually at most front side of the chassis where electronic RF is less influenced and receiving frequency is optimal. Straight upright receiver antenna high above from any VTX antenna or unobstructed L.O.S (Line Of Sight) signal receiving helps to improve the range away from noisy ground RF reflection.

Receiver compatibility

One of the important decision making when choosing the right radio is the future possibility of having more receiver unit once your R/C model collection grow because you might ended up 10x models per-radio unit, that's where RC4G unit fits well in this requirement where it used to be dominated by FLYSKY within budget range. Since i purchase the early version of RadioLink RC4G it comes stock with R4EH-G v1.1 receiver unit but the later version RC4GS comes with R4FG-G receiver or R4F receiver without gyro. So within RadioLink lines of compatible receiver for RC4G and RC4GS the R4FG,R8EF,R8FM, R4EH-H and R4EH-G unit are the list of receiver reported by R/C forumer that are compatible with each other. However there's also report at Rcgroups.com forum that some receiver might not be compatible due to binding issues but found out it was caused by firmware issues in the transmitter itself which required further firmware updates so before buying RC4G/RCFGS transmitter be sure you got the right firmware uploaded by the manufacturer by checking out updates at our forum discussion here: Rcgroups.com RC4G 2.4GHz 4CH pistol grip radio description----RADIOLINK. Currently in my hand i've used 2x R4EH-G v1.1, 2x R4EH-H and 4x HobbyKing TRACKSTAR TS4G V2 receiver without any problem because i'm still using old 2015 stock factory firmware on my RC4G. Oh btw if RadioLink brand receiver is out of stock you can also use compatible 're-branded' receiver from HobbyKing.com which is mentioned previously the TRACKSTAR TS4G V2 receiver works 100% well on RC4G and it also have built-in steering gyro too. Overall all the RC4G compatible receiver support between 4.4~8.6v (1~2s lipo) voltage input but some spec claimed to support as high as 10v however no one dare to input that high since most of us feed the receiver from ESC's 5V BEC line or 2s li-po during binding process only. Even it says it could support higher than 6V never ever plug 5~6V rated Servo unit along side 2S li-po or high rated voltage input because it will fry/burn your servo or anything lower than 6V rated devices plug into 3 pin servo type slot (signal | + | - ) pin... it was confirmed by other members of the forum, usually its a common sense for any experienced R/C'er. So best bet to use BEC to power the receiver via ESC's/BEC's unit like any R/C do just too be on the safe side. Extra tips: if you see a receiver that has ####-G alphabet signature (-G) means it has built-in steering gyro while ####-H signature (-H) means it support High Voltage around 10V.....but don't get duped by the -H signature because the outcome came be varies only the -G is trusted and helpful for racer and drifter. The one without -H or -G usually basic and cheaper.



Below are lists of popularly used 4 channel receiver for RC4G/RC4GS and its compatibles:

Videos/Medias

Here are sample of video of i posted on my Youtube channel that uses Radio Link RC4G radio unit mostly used for long range ground FPV driving.

Vendor/seller



Here are list of reputable vendor/seller which i bought from and also verified by community forum discussion groups. Also i've experienced buying from these places that have good support and services





Support group:



Places where you can find help and resources related to this product:

Topic: Rcgroups.com RC4G 2.4GHz 4CH pistol grip radio description----RADIOLINK

Manufacturer link: http://radiolink.com.cn

Manual download: http://radiolink.com.cn/doce/product-user-manual.html

Summary

I've gone through a lot of ground based Radio Control unit for more than 20 years starting from the old basic yet vulnerable AM/FM based frequency from to advance professional brand such as FUTABA, ACE, SANWA, SPEKTRUM, KO-PROPO to be used on several type of R/C models especially for racing and large area driving but nothing give me more satisfaction and happiness than the RADIOLINK RC4G that i have right now. Currently the most active weekend ground R/C radio i used are the expensive SANWA M11 and the el-cheapo RADIOLINK RC4G which i go out with them a lot however both seems to be different beast and one might wonder why wouldn't i go Pro with SANWA M11? Because SANWA receiver unit cost me 2x box of RC4G combos and the Pro level receiver ('R' type) doesn't play nice with standard servo which demand only high rate digital servo to serve its purpose else burned for good, Note i burned lots of servo due to high rate/high response signal from these expensive receiver. So its a good reason for me to stay cheap with RC4G combos so i can grow my hobby without holes in my pocket...plus RC4G perform as good as any Professional R/C controller with some extras and advantages especially with the long distance radio coverage useful for FPV enthusiasts. If you do get these cool RadioLink RC4G radio be sure to do research and checkout latest updates at R/C forum (https://www.rcgroups.com/forums/showthread.php?2272991-RC4G-2-4GHz-4CH-pistol-grip-radio-description-RADIOLINK) before buying it because sometimes manufacturer make some frequent changes, firmware and upgrade that you should know to ensure optimal compatibility with any receiver used which is why since 2017 and 2018 they have release latest updates with USB supported for firmware uploading and also extra 'S' behind RC4G (Latest RC4GS model). Btw if you're still hungry for more channel there are always RADIO LINK RC6GS around to keep you happy. So its safe bet to say there's nothing wrong going cheap with radio because i've been flying long range FPV with USD$50 too (Turnigy 9X/9XR) hehehehe!....and save me extra money to grow on other cool projects, lol.