Range issue x6r/x8r (many receivers have gone bad)

[miron]

Hello.
Four of my x4r receivers are dead. Now I use x6r and x8r. They never die. But I have range problems.
I have belt driven helis g420,g570 and gaui x3. I have anti static grounding from tail boom to battery - connector through fbl pin. It helps me to avoid sudden failsafe with high RSSI.
I crashed on this holidays my goblin 570 close to me at 10 meters. Range test of x8r from g570 is about 2-3 meters. I have also 3 x6r with low range.
I have good receivers with high RSSI, so it is not radio issue.
I change many receivers.
My opinion is that Frsky receivers are crap

[JWeber]

Can you post a picture of how you have the antenna's mounted on a heli you're having issues with? I've never had issues with FrSky receivers unless I've damaged them. If you're having consistent problems across many models and receivers, then it's either your transmitter or how you have the antenna's mounted.

[miron]

In 2 plastic tubes. One tube on buttom frame, second antenna on right frame. I removed receiver, heli is in country house now, not at home. I have old photos. Main frame on 570 is stock glass fiber

[JWeber]

I always try and get the antenna away from the main body of the heli to prevent shadowing. Here's how I do it on my Goblin.

[miron]

Goblin 570 has glass frame it is not electrical conductivity. Boom is connected to main frame on 570, but electic charge can't go to body, because it is glass. Therefore I've connected battery minus to tail boom. It halped me to not have fail-safe in flight on 570. I haven't problems for a long time. But fail-safe problem appeared again.
Goblin 420 has carbin frame, but boom is isolated. I have connected tail case to main frame on g420 and solved problems with fail-safe on spool up

[JWeber]

In that first picture, you could get some shadowing from the landing gear or the model (aluminum, motor, servos, etc.) itself if it's facing you with the nose slightly down. I've never had an issue with how I mounted my antenna.

[miron]

I have problem not with shading. New receiver has RSSI 70-80, old 40-50 in same place. Old receiver lost signal at 10 meters. One recevier doesn't work at all.
Good receiver will work with shading.

[Xtremespeed]

I hope you find the problem. I have been chasing the same problem for more than a year now. Every once in a while my Goblin 420 using an x4rsb would loose connection and crash. After that, the rssi numbers for that receiver would drop really low and no longer be usable. I tried everything to eliminate static and magnetic interference but nothing solved the issue. Killed 3 x4rsb’s. Decided to try an x8r and that seemed to have cured the problem until yesterday. The difference this time is my rssi numbers for the x8r still look ok. I never received a signal warning only got the telemetry lost notification and the rx went into failsafe. This was verified in my Ikon2 log. I suppose it’s possible this time is not related to the other rx failures considering the x8r doesn’t seem to be unusable like the x4rsb’s. I obviously don’t trust it though. Luckily, I was able to auto down this time, but might not be next time.

[miron]

Hello.
My friend gave me x4r in shrink tube and it hasn't died after 10 flights. My three x4r in paper stock cover died. I'm using x6r and x8r. They live longer, but some times lose signal strength. I think that plastic case gives protection. Goblin 420 flies without problems with anti-static connection.

Try to connect tail case to mainframe and check conductivity by multimiter. Some times carbon hasn't conductivity on surface without sanding.

I checked my 570, bolt on tail boom on left and right side lost connection to carbon in boom. I connected side bolts on boom to battery minus before. I changed connection on 570. Now tail case is connected by wire to upper metal frame (side frame are glass). 4 flights on 570 without problems, it is not enough to say that all is good. I will test it more and write about it.
You can set RX to use Rescue in fail-safe. This helped me some times. But last crash not, because fail safe was too short and brain stoped rescue at Signal OK state.

[Xtremespeed]

Thanks for the reply. I have already made mods to insure tail and boom are grounded to prevent static strikes. This did not help me. Only changing to x8r seemed to help but now suspect problem has returned.

[miron]

I haven't problems with antistatic connection and x6r for a long time, but connection between boom and grounding was lost. Hope, you will find reason of your problem

[Xtremespeed]

So far I’ve found it almost impossible to diagnose. I might make 20 flights or more before it happens. Works perfect for many flights and then for no apparent reason I get another failsafe. I also travel full time and have had the issue in several different geographic areas so I think I should be able to rule out interference. Very hard to duplicate. Out of curiosity what ISRM and receiver firmware are you using and which radio?

Oops. I see you have a qx7. Which firmwares though?

[miron]

FW x7-2.3.11-otx - radio
X8R_150115- receiver

[Xtremespeed]

I meant the firmware for the internal module (ISRM) and the ACCST receiver firmware. Likely 1.1.3 or 2.1.0. Was basically wondering if you were still on version 1 or on version 2 of the ACCST receiver firmware.

[miron]

I'm using old firmware. I am confused by versions and differences. Newes firmware for receivers doesn't work with radio. I havent updated radio FW.
But problems with receivers are hardware

[Atomic Skull]

Has to be somthing the OP is doing to cause a rash of receiver deaths otherwise this would be repeated for everyone and it's not.

I recall Extrapilot saying some component on the RX4R is very sensitive to static discharge from the antenna so if the way you are setting up your helicopters causes static discharge from the antenna tips rather that some other place on the heli (static likes to jump off the ends of pointy things) that could be the issue.

Grounding the tail will NOT help here, grounding distributes static evenly but it will still reach the point where electrons will jump off from somewhere on the airframe. The only solution is a static wick which provides a pointy spot that static will preferentially jump off the airframe from. Static wicks are how they solve this issue in full scale aircraft.

An easy way to make a static wick is to crimp a piece of CF tow line into a ring terminal and fray the end then put it on a screw where it hangs off the edge of the frame into open air. The tiny ends of the fibers will allow electrons to jump off at relatively low energy levels.

[miron]

I placed antennas of X4R in plastic tubes with shrink tube at the end. Buttom plate of my heli is plastic, side frame is glass fiber. On antenna is place on buttom and one on side
X4R from my friend with body in shrink tube did not die.
Noe antennas of X6R and X8R also are in tubes, but without grounding this receivers could loose signal or get fail-safe

[miron]

I've added Batterry Cells sensor to my protos 500. Boom is grounded to mainframe. I had no problems without sensor. But with sensor I had fail safe(rescue in MSH brain helped to save heli in RX fail state). Receiver didn't worked at close range. Only power reset helped. I removed wire from receiver to sensor. Now it works fine, but rssi level is lower, than new receiver

[Xtremespeed]

Some of the receivers I had that went bad, had very low rssi afterwards. That’s part of what makes me think it could be static that caused the issue. My son recently had an x8r go into failsafe on a Goblin 420 for no apparent reason, after probably 70 flights with no changes, and flying in an area he frequents. Nothing in the ikon logs that looks suspicious other than rx failsafe. Not everyone has these problems with Frsky but I’ve seen enough including mine and my sons to make me seriously consider switching to another brand. I don’t want to. I love the radio and Open Tx but I’m loosing confidence in them for helis. So far not one issue in electric prop planes or edf’s. I wish Frsky had customer service to help us with issues and at least determine the cause.

[miron]

Originally Posted by Xtremespeed

Some of the receivers I had that went bad, had very low rssi afterwards. That’s part of what makes me think it could be static that caused the issue. My son recently had an x8r go into failsafe on a Goblin 420 for no apparent reason, after probably 70 flights with no changes, and flying in an area he frequents. Nothing in the ikon logs that looks suspicious other than rx failsafe. Not everyone has these problems with Frsky but I’ve seen enough including mine and my sons to make me seriously consider switching to another brand. I don’t want to. I love the radio and Open Tx but I’m loosing confidence in them for helis. So far not one issue in electric prop planes or edf’s. I wish Frsky had customer service to help us with issues and at least determine the cause.

I think that tail belt had some wear that caused static. I also hadn't problems on new gpblin 420, but after 50 flights I had problems
Opentx is good platform, but Frsky hardware is cnot so good.
You can try to place antennas in isolation from main frame and connect main frame to tail case by wire as it done on pictures above.
Without antistatic wiring I had failsafe on spool up. That is, the problem has progressed. First failsafe was in flight, after some time I had failsafe at each spool up.