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Help with TX

aztech

Junior Member
#1
Hi, first post in here and here goes ...

I'm new in the RC community and I'm in the process of sketching up components to build my first 250 FPV quad.
Plan is to build quad and fly it and after some time (when the wallet allows it) buy some FPS gear and continue from there.


I have nothing at the moment and I need some advice on what transmitter to get.
I do like the idéa with telemetry, so if the TX has that option, it would be great. Mainly for keeping track of LiPo voltage, but perhaps also other data.

Other than that, I'm on a budget, so I'm looking for something that is rather cheap, has a minimum of 6 channels and is "good". I've read about modding a 9xr to support telemetry and so on, but all the combos with modules etc is beyond my knowlege so far.
 

pressalltheknobs

Posted a thousand or more times
#2
The most inexpensive telemetry system is the FlySky/Turnigy i6 AFHDS2A with the iA6B Rx. The iA6B also supports PPM which is good for multirotors.
You need a voltage sensor to monitor the main battery.

Note: The iA6 RX that comes stock with the Turnigy i6 does not support telemetry sensors but does return the RX voltage and can be modded to return the battery voltage instead.

One issue with telemetry on the i6 is that the only alarm is for the RX voltage. Otherwise you just get to display the value on the TX. Still for the money it's a very good value.

There are other better choices if you have more money to spend.
 
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Techno

Sunny Day Park Flyer
#3
WELCOME TO THE FLITETEST FORUM!

I've found that a transmitter can be the best investment in the hobby. For telemetry, the 9XR Pro supports Telemetry, and it's easy to program, but it can be a handful to setup. RCModelReviews has a video about it, so you can check YouTube.

But if you want to go cheap, like knobs said, you could just get a battery alarm for your model and it will beep when the voltage gets too low. Also, since you want to take the plunge into FPV, you can also get an OSD (on screen display) to display your battery voltage, flight time, and even GPS location. Flight controller also can do that sort of stuff

I think you should get a normal radio for a bit more (with more channels if you want) and just get a battery beeper and a lost model beeper, you should be fine.
 
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pressalltheknobs

Posted a thousand or more times
#4
WELCOME TO THE FLITETEST FORUM!
But if you want to go cheap, like knobs said, you could just get a battery alarm for your model and it will beep when the voltage gets too low.
Actually not quite what I said but a battery alarm is a good inexpensive option that I definitely recommend. The i6 voltage sensor thing is genuine telemetry and it is very easy to set up. Just not quite all you would want. They kind of missed only having an alarm on the RX battery level. Still you get it almost for free with this TX so it's a good place to start if you have a tight budget.
 

aztech

Junior Member
#5
Thanks for the input.
The i6 looks like it's withing my budget, so it could be the way to go.

As it is a cheap transmitter, are there any drawbacks or so regarding programming etc?
 

Epitaph

Ebil Filleh Pega-Bat ^.^
Mentor
#6
For a couple of dollars more I prefer the Walkera Devo 7E http://www.banggood.com/Wholesale-Walkera-Devo-7E-7CH-Transmitter-Mode-2-Without-Receiver-p-48117.html, as it also has telemetry, but can be upgraded to Deviation which allows for multiple protocol uses like DSM2, DSMX, etc, and other protocols by adding cheap modules internally (if you like to tinker) including FrSky, FlySky, WLToys, and many others. With the software upgrade it becomes a 12 channel transmitter and you can add on an extra 2 three way switches for direct access, other channels being accessable via reassigning of buttons or even using trims for channel control.

I have this radio and I love it!!

Now... the programming can be a little daunting at first, like with the Taranis, but on the Deviation website there are plenty of .ini files for different models that people share, and you only have to copy and paste them (changing the name accordingly to the model number you want it to be) via the USB connection.
 
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pressalltheknobs

Posted a thousand or more times
#7
The Walkera Devo 7E is certainly interesting. Makes a lot of sense if you are a micro helicopter pilot. But I would need to research it some more. Also note that while it's fairly inexpensive on banggood it does not come with a receiver.

A quick search indicates that it has limited range stock and it's a soldering project (and possibly some money) to get it changed to full range. Might be a fun project and I like that about it. If you have one, the mods can make sense. But buying one new to do that is a little more dubious a proposition.

You almost certainly need a ham license to make this modification and use it....

http://www.hacksmods.com/2013/04/walkera-devo-7e-transmitter-increase-range-mod/

I think there are other ways to do it also.

This is the site for the Deviation firmware
http://www.deviationtx.com/

and if you are interested in Deviation here's a discussion of the pros and cons of the various Txs that it is supported on.
http://www.deviationtx.com/articles/21-which-devo-tx-should-i-buy

btw. That page says the says the 7e has only 7mW output power. That could be a typo or they may have changed since it was written because the manual says <= 100mW
http://walkerahelicoptersupply.com/products/devo-7e-transmitter
 
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Epitaph

Ebil Filleh Pega-Bat ^.^
Mentor
#9
Considering an Orange receiver costs about $5 and is fully compatible once you install Deviation... also, it's not JUST for microhelis, as Deviation is an opentx based system and you can control anything with it. I have delta mix on mine, I can program a butterfly system (crow) no problem, I wouldn't even have a problem controlling an up-market quad with it!! There are not many things I can't do with it once the software is changed. You've basing the "microheli" opinion on the basic Devention operating system, and in that sense I would agree, but a small, free mod inside turns it into a full range transmitter, so not even range is an issue as I now have 150mW transmitting power!! Another way to do it is to get the transmission module from the 6S and install it, which is full range, and no HAM licence needed.
 
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pressalltheknobs

Posted a thousand or more times
#10
Considering an Orange receiver costs about $5 and is fully compatible once you install Deviation... also, it's not JUST for microhelis, as Deviation is an opentx based system and you can control anything with it. I have delta mix on mine, I can program a butterfly system (crow) no problem, I wouldn't even have a problem controlling an up-market quad with it!! There are not many things I can't do with it once the software is changed. You've basing the "microheli" opinion on the basic Devention operating system, and in that sense I would agree, but a small, free mod inside turns it into a full range transmitter, so not even range is an issue as I now have 150mW transmitting power!! Another way to do it is to get the transmission module from the 6S and install it, which is full range, and no HAM license needed.
I don't doubt changing the firmware is a big improvement. My comment about micro helis wasn't meant to imply that you could only use it for micro-helis. It's the fact that you can control them maybe by just changing the software that makes the DEVO line of Tx attractive vs others.

My "opinion" is that buying a TX knowing you have to make a modification to the RF Transmitter circuit with a soldering iron to get it to have decent range seems like a dubious proposition. Even if it is a small mod it's not something anyone should take on unless they know what they are doing. The poster of the mod description clearly didn't as he left off the RF shield on one radio and hot glued it on another! That is not correct! It has to be soldered back on to stop unwanted rf radiation being broadcast and from interfering with the TX. Even if this mod is successful how do you know it not creating a lot of spurious noise for other 2.4Ghz users unless you have appropriate test equipment? Plus it seems that sometimes the mod doesn't work and then you have to solder in a whole new tx module. Imo you would have to already own one for any of this to make sense and even then it's not for everyone.

And yes you can buy a cheap Orange receiver but you still have to buy something. Again this is great if you already own a Devo 7 but if you have to make a modification before that something will work you would have to have a good reason to buy it in the first place.

If you have one and have made all the mods and you are happy with it that's great but anyone considering buying one should know what they are getting into much like if you buy a FlySky/Turnigy 9X you should know that it is PITA to upgrade the firmware unless you get something like the smartie parts board.
 

Epitaph

Ebil Filleh Pega-Bat ^.^
Mentor
#11
But then you are also assuming that everyone likes everything to work perfectly straight out of the box, without realising that there are some of us that like to get something to adapt and manipulate, "tinker" if you may, because some of us have just as much fun in the workshop as in the air, and that is something a lot of people with RTFs nowadays can't seem to comprehend, like making a balsa build and using white wood glue to build it. I am someone that enjoys it, and in the example of the 9X, I would get it specifically to mod, to personalize, like with the backlit screen, the FTDI module and things like that. It's like those that buy an arduino development board to learn to program, and those that want to buy something that is task specific, eventhough it may be arduino based. Part of the fun is the build itself.

The Devo 7E is exactly like that, as a developers transmitter... and if you look at the list of protocols it can handle it's very good, especially considering the final price. There are I understand a few places that even sell the readily modded 7E's for a small fee more. And yes, the signal can disrupt WiFi signals when turned onto maximum as it even disrupts my own WiFi at home... solution, don't use maximum setting if you don't need maximum setting. Also, a first time radio owner doesn't usually worry about things like telemetry or stuff like that until they have learned to master at least LOS flight... it is a pretty well known fact that this hobby seldom involves buying one transmitter for life. If on the other hand you are into technical things like setting up FPV, programming control boards, and running telemetry sensors, then really a small, easy mod is a cakewalk and you just have to remember basic things like if there is an RF shield, it must be there for a reason.

If the reason for not getting into the electronic or building side of things is because of lack of experience, well, nobody was born knowing and everyone started trying somewhere. Now, I've seen some very lame excuses on this side of the pond for example as to why people don't balsa build anymore, the biggest reason being "I don't have time for that"... yet they have time to be every football match glued to the TV for 90 minutes. Considering that football is a game where not much happens most of the time, to the extent of being probably the only sport that can end 0-0, I don't see how whose people can't glue a couple of pieces of wood together WHILST they are watching nothing going on!! Me personally, I usually do my building and tinkering with at least a movie/series running and reading through forums and facebook at the same time... now I know I'm a weird subspecies, but it' not that hard.

The range mod is not as hard as it seems, believe me. And also, don't base range on mW, because if you did that, you would never even consider Multiplex radios to be any good... the reason they were one of the last ones to bring out a 2.4ghz was bcause there is a huge power restriction on 2.4ghz systems in Europe, and they didn't want to release a system until it fully complied with the norms and still had a good range... those M-Link systems have a range of a mile and a bit, yet the are, on the books, the only ones really fully legal in Europe, as all the other brands actually transmit too much power for the norms to achieve the same range. Also, just as is with car horsepower rating, the specified power on paper isn't usually the specific power, but rather a "minimum" power... as many have tried out their 7E's and gotten a lot more, even double those 7mW that are advertised. I personally did the range mod because I can, not because I need...
 

Epitaph

Ebil Filleh Pega-Bat ^.^
Mentor
#12
I would also like to point out that the thread initiator is building his own quad, sketchuping his design and everything, and I applaud him for his initiative!! He must also know that at least a basic level of soldering is needed in this for the power distribution, and he has been looking into "telemetrying" a 9XR but found it a bit beyond his skill set, but never mentioned in what what it was beyond him. He may very well know how to solder, and in this case a range mod is something very easy, as well as the addition of modules should he wish to add any. Changing the transmitter's firmware is very easy to do, and there are not only comprehensive instructions on how to do it, there are even plenty of video tutorials showing step by step how to do it. I threw an idea, an option out there that does permit growth very much so, and the ability to use RTF planes most of which are DSM2/X, and he can evaluate it and decide if he can or cannot do it. But assuming that a particular knowledge is beyond someone off the bat is a little extreme.

If he decides he likes the idea, great... if he wants me to help him with any of the issues he might have concerning it, no problem. If he decides not to go for it because of a certain skill set or because he prefers another transmitter, fine... but I threw that out there for him to decide. He is looking for a capable radio on a very tight budget, and I offer an option. If it wasn't on a budget, then I would say the Taranis or the Devo 10 probably... and I guess you would shoot me down on the Devo 10 because of the firmware part of it (installing Deviation), although I doubt you would say anything against the Taranis eventhough you really have to know what you're doing to program it too... but that's because the Taranis is the FT forum's holy grail, and everyone should bow down to it!!
 

aztech

Junior Member
#13
Oh, this got a bit of a discussion ...

First, by saying "sketching", I actually meant that I'm sketching on a list of things to boy.
I think I'm going for a kit like this ->http://www.myrcmart.com/rcx-h250cf-...6-1950kv-motor-12a-esc-5030-kk-21-p-8499.html
with some modifications perhaps.

Regarding the radio, I actually think I'd go for a FlySky or similar in that price range.
The radio is as said earlier in this thread, something one can upgrade at a later point.

Now I'm only interested in getting up in the air as soon as possible and regarding the FPV stuff, this will be invested in at a later point in time. I for certain is not made of money.