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Gliderguy
Guest
Maybe I'll just get one anyway despite the mixed reviews. 
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The G-RX8 receiver is NOT ready for the mass market
- Thread starter Konrad
- Start date
Konrad
Very Strong User
If it has the features you want it is now a very good RX. I actually have flown one of mine twice.
Other than my comments on poor engineering for lack of "polarity" protection (Pre 3/2018 production), what are the mixed reviews?
https://alofthobbies.com/frsky-g-rx8.html
I now enthusiastically recommend this RX with a redundant RX like the XM+.
https://alofthobbies.com/xm-plus.html
The onboard Vario actually works for those that want this feature. This now makes adding this feature very easy, even in small gliders, 2 meters and smaller, with no real weight penalty.
All the best,
Konrad
Other than my comments on poor engineering for lack of "polarity" protection (Pre 3/2018 production), what are the mixed reviews?
https://alofthobbies.com/frsky-g-rx8.html
I now enthusiastically recommend this RX with a redundant RX like the XM+.
https://alofthobbies.com/xm-plus.html
The onboard Vario actually works for those that want this feature. This now makes adding this feature very easy, even in small gliders, 2 meters and smaller, with no real weight penalty.
All the best,
Konrad
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Konrad
Very Strong User
Please be aware that there are now effectively 2 RXs with the same name G-RX8. The earlier production model without "polarity protection" and then the properly designed one with a post 3/2018 production date that has the "polarity protection" on the output pins.
This is such a drastic change in durability that I think FrSky should have added something to the name to show version revision. Maybe called it a G-RX8-v2 receiver!
I hope Aloft will add a description to their sales page allowing us to differentiate between both production runs. I think the case is different.
This is such a drastic change in durability that I think FrSky should have added something to the name to show version revision. Maybe called it a G-RX8-v2 receiver!
I hope Aloft will add a description to their sales page allowing us to differentiate between both production runs. I think the case is different.
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Konrad
Very Strong User
Warning!!
If using external sensors (Smart Port [S-Port]) please be aware that FrSky does NOT respect any standard pin output. This is another trap waiting to grab the customer!
Please see photo of the X4R and G-RX8 S-Ports
FrSky does provide adapters from the micro connector to the standard Jr style S-Port connector. But as the micro connectors are PHYSICALLY interchangeable it is still very easy to plug in the wrong adaptor cable into the RX.
Again a failure at the engineering level! Not sure why the PCB didn't bring the S-Port pins out in a previous defined order. But one would think a simple jumper would have corrected this.
I highly recommend that one label ones micro connector S-Port adaptor cables RX specific!
P.S.
I do like the pin call out of the G-RX8 much better than that of the X4R as it isn't likely to cause a short should you by accidentally "force" the connector into the socket. You will note that reversing the X4R's micro connector will reverse the Positive (+) and Negative (-) pins!
If using external sensors (Smart Port [S-Port]) please be aware that FrSky does NOT respect any standard pin output. This is another trap waiting to grab the customer!
Please see photo of the X4R and G-RX8 S-Ports
FrSky does provide adapters from the micro connector to the standard Jr style S-Port connector. But as the micro connectors are PHYSICALLY interchangeable it is still very easy to plug in the wrong adaptor cable into the RX.
Again a failure at the engineering level! Not sure why the PCB didn't bring the S-Port pins out in a previous defined order. But one would think a simple jumper would have corrected this.
I highly recommend that one label ones micro connector S-Port adaptor cables RX specific!
P.S.
I do like the pin call out of the G-RX8 much better than that of the X4R as it isn't likely to cause a short should you by accidentally "force" the connector into the socket. You will note that reversing the X4R's micro connector will reverse the Positive (+) and Negative (-) pins!
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Gliderguy
Guest
The mixed reviews mostly dealt with reliability issues possibly due to polarity problems like you ran into (don't know for sure). But also there was the firmware upgrade issues and one guy mentioned that the vario was too slow reacting for him. I don't think any of these will be a problem for me since I probably won't upgrade and I'm kinda slow reacting also and I guess the polarity issue is solved. It will take me a while to figure out what a smart port is.
A vario would be nice sometimes to help read the air.
Thanks for the detailed review.
Dale
A vario would be nice sometimes to help read the air.
Thanks for the detailed review.
Dale
Konrad
Very Strong User
S-Port is mainly for adding extra sensors, or add ons.
I'd like to see everyone get a XM+ RX when purchasing the G-RX8. The redundant RX feature of this generation of receiver is what makes this receiver special.
When I started to fly Thermal Duration (TD) gliders, I too thought that the Vario would be a huge benefit. But after about the tenth flight I tore them out. They really are very annoying and distracting to my way of flying. Now if I was flying cross country I might reevaluate their worth.
All the best,
Konrad
I'd like to see everyone get a XM+ RX when purchasing the G-RX8. The redundant RX feature of this generation of receiver is what makes this receiver special.
When I started to fly Thermal Duration (TD) gliders, I too thought that the Vario would be a huge benefit. But after about the tenth flight I tore them out. They really are very annoying and distracting to my way of flying. Now if I was flying cross country I might reevaluate their worth.
All the best,
Konrad
Konrad
Very Strong User
Gliderguy, I see on RCGoofs that you are asking about the Vario. https://www.rcgroups.com/forums/showthread.php?3068867-Are-varios-worth-it
Being as this RX comes with this gimmick it would be perfect for trying one out. If you are like me and don't like them you can turn off the Vario in the telemetry screen. Or if you find that you do like them, step up to some of the ones Wayne mentioned or upgrade to this in the mean time. I will say the High Precision Vario will respond to 4' of change! Now if that is a good or bad thing I'll leave that up to you.
https://alofthobbies.com/frsky-high-precision-vario-fvas-02h.html
Again the beauty of this RX is in its form factor (narrow) and that it can use a redundant RX. The Vario really is a low level feature.
All the best,
Konrad
Being as this RX comes with this gimmick it would be perfect for trying one out. If you are like me and don't like them you can turn off the Vario in the telemetry screen. Or if you find that you do like them, step up to some of the ones Wayne mentioned or upgrade to this in the mean time. I will say the High Precision Vario will respond to 4' of change! Now if that is a good or bad thing I'll leave that up to you.
https://alofthobbies.com/frsky-high-precision-vario-fvas-02h.html
Again the beauty of this RX is in its form factor (narrow) and that it can use a redundant RX. The Vario really is a low level feature.
All the best,
Konrad
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Konrad
Very Strong User
MEA CULPA (maybe)
I was reading the pamphlet for the G-RX8 in detail. I noticed that in S-Bus mode the signal pin on Channel 7 is DEAD (no output)!
I know I bound my RX in PWM mode (Jumpers on signal pins 1 and 2).
I know that all seven servos ran when initially powered up.
I saw a spark when I mispluged my flap servo on ch-7.
I had assumed that this burned out channel 7. Now I wonder if the receiver really didn't just reboot in S-Bus mode.
As an academic exercise I'd like to get back my original RX to test out this hypothesis.
I was reading the pamphlet for the G-RX8 in detail. I noticed that in S-Bus mode the signal pin on Channel 7 is DEAD (no output)!
I know I bound my RX in PWM mode (Jumpers on signal pins 1 and 2).
I know that all seven servos ran when initially powered up.
I saw a spark when I mispluged my flap servo on ch-7.
I had assumed that this burned out channel 7. Now I wonder if the receiver really didn't just reboot in S-Bus mode.
As an academic exercise I'd like to get back my original RX to test out this hypothesis.
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Konrad
Very Strong User
As luck would have it Aloft Hobbies still had my returned Rx. Wayne happily gave it back to me so I could run some experiments on it.
Well, you guessed it the G-RX8 performed as described in the manual. While this does put some egg on my face, it is good news.
When I misplugged the servo lead into the RX I did not burn up the output junction of Ch 7, as I had feared. I don't know how but it looks like the "short" rebooted the RX in S-bus mode.
If one takes the time to read the manual one learns that In S-Bus mode Ch-7's output is dead. This falsely lead me to think that I had burned up the output for Ch-7. I did NOT do my due diligence and try to rebind the RX prior to my returning it to Aloft Hobbies.
I owe Wanye an apology for all the run around with this RX.
While I still think FrSky made the wrong decision in bringing to market a RX that is not polarity protected. But the unit I had did not fail when I misplugged the RX. I think both FrSky and myself got very lucky with this particular receiver.
With egg on his face,
Konrad
P.S.
I have not, nor will I, do a proper test and purposefully misplug the servo lead to see how the RX behaves
All tests have been bench tests. I have not flown this RX.
Well, you guessed it the G-RX8 performed as described in the manual. While this does put some egg on my face, it is good news.
When I misplugged the servo lead into the RX I did not burn up the output junction of Ch 7, as I had feared. I don't know how but it looks like the "short" rebooted the RX in S-bus mode.
If one takes the time to read the manual one learns that In S-Bus mode Ch-7's output is dead. This falsely lead me to think that I had burned up the output for Ch-7. I did NOT do my due diligence and try to rebind the RX prior to my returning it to Aloft Hobbies.
I owe Wanye an apology for all the run around with this RX.
While I still think FrSky made the wrong decision in bringing to market a RX that is not polarity protected. But the unit I had did not fail when I misplugged the RX. I think both FrSky and myself got very lucky with this particular receiver.
With egg on his face,
Konrad
P.S.
I have not, nor will I, do a proper test and purposefully misplug the servo lead to see how the RX behaves
All tests have been bench tests. I have not flown this RX.
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Gliderguy
Guest
Glad we all learned something.
Just went to buy one and now it's out of stock, Oh well, later maybe.
Just went to buy one and now it's out of stock, Oh well, later maybe.
Fix for 'useless' altitude --- Take your plane for a ride, in an elevator that you know the gain in elevation of - then use the Ratio number to correct it. My X8 read 75ft at 84ft of change - I put in the correction Ratio number and it now reads to within +-0.2ft. @ 84ft. So just a bit over a foot at 500' - works for me. If you can find a taller building and talk to a building engineer to find the floor height you could probably get closer.
They were repeatable on two different days and at a stop about half-way up. Yes, if you zero at the top it reads minus feet on the way down. I did end up 'cheating' in that the Ratio number will only go in to one decimal place. I wanted it better so I put in 27.2 instead of 2.7 so the reading is X10; at 100ft my screen has 1000 on it, I don't find dropping the extra digit a problem, if I could toss a DLG to above 1,000ft I would not have to buy any RC gear!
According to the book on a QX7 sold by Aloft the math is supposed to be :: (Reading / 255) * Ratio + Offset = Screen Reading. I ended up with :: ((Reading * 100)/255) * Ratio + Offset = Screen Reading :: to get this to work out. I left the Offset at 0. I contacted the author and he ran a check on another Rx with altimeter and agreed that the math in the book did not work out. This book is the only place I have found anything on how to come up with the Ratio number.
According to the book on a QX7 sold by Aloft the math is supposed to be :: (Reading / 255) * Ratio + Offset = Screen Reading. I ended up with :: ((Reading * 100)/255) * Ratio + Offset = Screen Reading :: to get this to work out. I left the Offset at 0. I contacted the author and he ran a check on another Rx with altimeter and agreed that the math in the book did not work out. This book is the only place I have found anything on how to come up with the Ratio number.
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psfales
Guest
Konrad wrote in an earlier message on this thread: "FrSky does provide adapters from the micro connector to the standard Jr style S-Port connector." Any idea where one might purchase those adapters? Or the individual micro connectors? I've been scouring the internet without success. Thanks!
Konrad
Very Strong User
These normally cost $40, but this should do it. Don't forget to re-pin the the micro block (easy to do with the tip of a #11 blade). The X4R and G-RX8 don't share the same Smart port pin call outs (see post #24)
alofthobbies.com
You could add your own Jr connector
alofthobbies.com
alofthobbies.com
FrSky Smart Port harness for X4R and X4R-SB
An easy to use Smart Port harness for the X4R receivers.
You could add your own Jr connector
FrSky Wire set from D4R-II (also fits X4R)
Replacement wire set from the D4R-II receivers. Includes 2 harnesses as pictured. These are great for replacing damaged harnesses, or making new custom harnesses for the D4R-II, X4R or X4R-SB receivers.
alofthobbies.com
FrSky GRX8 Vario Rx With UNI-RX
We are grateful to FrSky for entertaining our idea for a specialized glider receiver. After ?much/months? back and forth working out the design considerations, the basic plan for the G-RX8 had been laid out. The G-RX8 design features really help it to sta
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