FlySky FS-GT3B opinions.

[90Finder]

What are your thoughts for a first timer? I'm considering purchasing one with multiple receivers, it looks like a great setup for the price but I've never used anything besides regular RTR axial and Losi set ups.

[90Finder]

Link to the one i'm considering.

FlySky FS-GT3B Digital 3ch 2.4ghz TX & RX LCD Transmitter & Receiver

[Charlie-III]

Even though I'm a long time Futaba fan (I run a 3PM-x, son runs a 4PL, I have many other older Futaba radios I still use in "go-fasts"), I think the GT3B or GT3C are great radios with a low price.
Depending on what you want to do down the road, I will suggest getting a hacked GT3B/C. You get more channels (rear steer, winch, lights, etc.) as well as more options for 3 channel than a stock GT3B/C.

LosiKid at OverkillRC does the hacked radios and other bits.

I have a hacked GT3B in my 2.2 comp rig with dual ESC's and it works well.

LosiKid does a great job supporting the hacked radios and multiple people also help out. There is a dedicated hacked GT3B thread here in electronics.

You can always buy a stock radio & hack it later on if you want.

[spillproof]

I bought one for my MOA, and the hack kit. I like it a lot, and for the price you can't really go wrong.

[losikid]

Originally Posted by 90Finder

Link to the one i'm considering.

FlySky FS-GT3B Digital 3ch 2.4ghz TX & RX LCD Transmitter & Receiver

I would recommend this one over that one...

Products - OverkillRC

[Deerhurst]

great radio. hack it, do a VR mod and a display mod.
with the VR mod you can run lipo or just run the AAs. your battery life will increase. dont use the one thats recommended on rctech. youll find the part number in a google search. i recommend pulling the part number off the old one and finding one in the same series that does 1A+. the stock one outputs 5v at 0.5A. i swapped mine with a VR that can handle 7-15v in and does 5v and 1.5A out.

the display mod helps make the display easier to see. just take the polarized layer off the display and flip it. just stick the polarized layer on the inside of the display window on the upper bit of the case.

[losikid]

Originally Posted by Deerhurst

i recommend pulling the part number off the old one and finding one in the same series that does 1A+. the stock one outputs 5v at 0.5A. i swapped mine with a VR that can handle 7-15v in and does 5v and 1.5A out

I disagree 100%

[90Finder]

Thanks guys for all the info, I found the hacked thread and it seems you can do just about anything with this setup. My mind is definitely made up now!

[Deerhurst]

Originally Posted by losikid

I disagree 100%

for what reason? your output requires 5v at .5A. something that can output 3x the amperage is more efficient. the chip will use what it needs and no more. a wider input is always good. i can look up the exact VR i used sometime around the 6 or 7th when i get back to where my radio is.

the recom VR that is suggested is not very efficient, much better then stock but still not ideal. it also takes up more physical space.


same series may be not too good but it is easy.

[losikid]

Originally Posted by Deerhurst

for what reason? your output requires 5v at .5A. something that can output 3x the amperage is more efficient. the chip will use what it needs and no more. a wider input is always good. i can look up the exact VR i used sometime around the 6 or 7th when i get back to where my radio is.

the recom VR that is suggested is not very efficient, much better then stock but still not ideal. it also takes up more physical space.


same series may be not too good but it is easy.

I think you need todo some research before making such wild accusations.

The recom VR (also the one i sell) is 90% efficient...and i dare you to find something more efficient that is a direct replacement and less than what a recom costs. I'm not saying 90% is as high as it gets, but without additional circuitry or a really high price tag, its really hard. I searched for quite sometime before settling with the recom. It's price is abit high, but you'll save the costs after one set of batteries.

With the stock VR, the radio pulls ~130ma with the backlight on and ~110ma with the backlight off.

Toss a recom in there, and it pulls ~75ma with the backlight on and ~60ma when the backlight off.

So it will nearly double the battery life


.5A is more than ample for the gt3b, adding more to its power handling capabilities doesn't necessarily make it more efficient... According from what you've described, you simply replaced a 7805 regulator with a 7805 regulator that can handle more current. And no mater what, a 7805 is a linear regulator so to get the low voltage, it turns some of the high voltage into heat. Which means not very efficent. If you do the math, at 12 volts, a 7805 runs about 40% efficiency in a setup like this

So, to make math easy lets say the GT3B needs 5 volts and 50ma of power. Figure that out in watts. 5 x .05 =.25 watts
Now figure out the power lost in the conversion
12 volts - 5 volts = 7 volts
7 volts x .05 amps = .35 watts
Now add those two figures together to get total power
.35 + .25 = .6 watts

So to find effiency, .25 watts divided by .6 watts = .416 or 41.6%

This is true for any 7805 regulator, possibly worse depending on the quality of the VR

You could argue that you found a switching regulator in a TO-220 package, but that would mean it requires additional circuitry or it costs more than the recom. I have yet to see a TO-220 switching regulator that costs less than the recom.

A switching regulator, can theoretically, have 100% efficiency, It simply rapidly switches the voltage so less voltage comes out. It needs other circuitry though to make it a nice smooth output. Most, require this to be external. However, the recom packs it all into one nice package to be a direct TO-220 (7805) replacement.

Also, you mentioned that the recom is bigger and takes up more space, which i have to disagree with again. The recom has a smaller foot print than a TO-220 package. Its thicker than the TO-220 package, and may have slightly more volume than a TO-220 package. But its alot more compact, and i'm pretty sure anyone who has to design a circuit board would much rather the recom package on there than a TO-220, unless they needed the board to be thin, but in that case, go SMD. OR, if you want to factor in the heat sink that the TO-220 should have on it, then the recom is ALOT smaller than that the TO-220 package.


Feel like arguing some more? We can get very technical if need be. I am very confident, that there is not a TO-220 package regulator that is MORE efficient than the recom and CHEAPER than the recom.

There may be another switcher thats more efficient than the recom, and slightly cheaper, but i doubt it (especially if its a drop in replacement for a 7805)

Back on topic....its a great radio for a first timer, don't let all this silly talk about vr's worry you. I promise you the VR i sell is a excellent option and its what 98% of the people who preform the mod choose

[rockhugger]

yeah so there









the gt3-b is the shit... I like it because I don't need a 4 or even a 2 hundred dollar radio to crawl, trip onto the rocks or drop and break while I'm out crawling.

[smoedog]

I got mine a while back for racing short course, hacked it and have never looked back since. I laugh at the guys with the 400 dollar radios and 80 dollar receivers.

For 1 of their receivers I can get a radio and control my entire fleet.

[NHebayer]

I love mine stock.... Waiting for my Hack kit and VR to arrive.

I'm very nervous about the firmware update... but people tell me its easy and Overkill gives great support.

[smoedog]

The update is simple, almost fool proof. I have a spare radio I need to hack. Only gripe I have with them is the brake post on the trigger is weak and I broke it off my first one. Probably going to wrap it in fiber glass an ca it to strengthen it up

[olywrestle]

Losikid, your hack kit works on both the 3B and the 3C with the same feature set right? So either radio would be a good choice?

[losikid]

Originally Posted by olywrestle

Losikid, your hack kit works on both the 3B and the 3C with the same feature set right? So either radio would be a good choice?

Correct...i sell two different versions of the hack though

[90Finder]

Ordered one up. Cant wait to get it!

[Charlie-III]

Originally Posted by 90Finder

Ordered one up. Cant wait to get it!

If the "C" is like the "B" (LosiKid says it's better), you WILL like it. I may have swayed my son from his Futaba 4PL (I'm a Futaba fan....have been for a few DECADES) to a hacked GT3B/C.

To buy a hacked 8 channel radio for the cost (or a little more) of a Futaba 4PL/3PM-x RX is sorta hard to pass up.

[gtxr]

Just get the C or B hackes and Vr mod.. Its way cheaper than any other 4 channel never mind 6-8 capabilities!! Great radio for the price!!

[ghtpdm5]

well, ran my b for a long time and as far as i know (went out the door to someone that would use it after i got my c) its still going.

my thoughts on the radio are pretty simple, hack it, put a bearing on the wheel, install the vr from overkillrc, and put a deans plug on the power leads for a lipo. that's a pretty short list of stuff to have a very solid radio that can handle just about anything. i've got my losi based crawler, my duratrax vendetta buggy, and my tamiya edu-toy tank experiment all on my c (c and b both were running the same fw). when driving my crawler on course, all the controls are perfectly placed, and the lighter c and b after lipo is welcome. before this i ran a spek dx3e, while this is a good budget radio on paper, my gt3c simply blows it out of the water for about the same price in the end. the features of the 0.6.1 fw really make this radio a super star. the ergonomics, for me (very subjective thing) are far better than the 4pl, 4pk, and dx3r. some of that is the weight balance of the radio, some of it is the grip to wheel distance being very easy on my hands. the 4pl's grip did not feel right, same with the 4pk (4pk also felt top heavy). the dx3r felt the best out of the "high end" radios, but the wheel placement was wrong.

i could go on and on about the features, i've played around with a lot of them, some stuff was pure happy coincidence. one thing here is that once you learn what the on-screen acronyms mean, you've about mastered the programming. now the acronyms are a bit tough in the beginning, but i just sat down with a couple servos hooked to the rx and the manual in front of me. the tank was a bit of a challenge, due to the way i rigged the speed controllers, i had to trim and mix them on the fly. not fun no matter what brand is in your hand. took about 2 hours to get is completely programmed, trimmed, and mixed. on my losi based crawler, its a 10 minute job to do, and while i was playing with servo winches, i did a moa mix in under 30.

now there are always people that call me out on being biased on this, but if i didn't like the radio, i wouldn't run it. it would have gotten sent back to overkill, and i would have either bought something else, or kept the dx3e. i don't have to run things i get, but so far, i haven't had anything come from overkill that i didn't love.