RF module for spectrum?

[XPS]

The RFU is actually -107dBm in a controlled test.

You should be able to turn on/off the transmitter and if the failsafe is really set to HOLD last position (and not USER defined) then the servos should stay put. You should not see any amount of movement. Unless you deliberately changed the RFU's settings the failsafe defaults to USER defined with preset positions at 1500us. It is recommended that you do the live-active failsafe setup. You do that by powering on your system so you can move the servos and then press and HOLD the button on the RFU until the LED started flashing red/green. You will have about 7 seconds to positions the sticks and switches on the transmitter where you want them during a failsafe condition. Typically this will be all neutral sticks. The purpose of failsafe is not to save your aircraft - it is to provide you with some insight of where the crash will most likely occur so that people can be moved out of the way. We typically provide a small amount of up elevator and rudder to cause a deliberate spiral pattern during a failsafe condition.

The RFU works down to 2.1v, so the voltage level you are talking about will not affect it.

[erhard52]

The RFU is actually -107dBm in a controlled test.

You should be able to turn on/off the transmitter and if the failsafe is really set to HOLD last position (and not USER defined) then the servos should stay put.  You should not see any amount of movement.  Unless you deliberately changed the RFU's settings the failsafe defaults to USER defined with preset positions at 1500us.  It is recommended that you do the live-active failsafe setup.  You do that by powering on your system so you can move the servos and then press and HOLD the button on the RFU until the LED started flashing red/green.  You will have about 7 seconds to positions the sticks and switches on the transmitter where you want them during a failsafe condition.  Typically this will be all neutral sticks.  The purpose of failsafe is not to save your aircraft - it is to provide you with some insight of where the crash will most likely occur so that people can be moved out of the way.  We typically provide a small amount of up elevator and rudder to cause a deliberate spiral pattern during a failsafe condition.

The RFU works down to 2.1v, so the voltage level you are talking about will not affect it.

great inside as usual - thanks a lot
the more i am looking into different RC systems the better the XPS system looks . how could it have disappeared? i listened to the AI story and the Graupner (i am german and that i why i love my multiplex EVO) issues - too bad this happened.

i did not change the failsafe conditions and subsequent power off tests dis not show the movement. 

anyways one last question (that could be a lie) - do you think i should be able to make the Spektrum SRXL2 DSMX Remote Serial Telemetry Receiver, SPM4651T work with the x10+ v2?
i did spend hours and it did not work. i programmed the x10 to input mode 3 flashes and tried all 4 binding modes to no avail. the SPM4651T was bound to my tx16s with DSMX protocol.

here a link to my various attempts
https://1drv.ms/w/c/9dc6d60a8cb4c333/IQD...E?e=zRuVze

here comes bonus contribution.
i scoped the X10 signals and other than channel one all look really bad
https://photos.app.goo.gl/Pex23SwM2HYKaFZq6

[XPS]

The SRXL protocol used by the newer Spektrum receivers is not supported by the X10+.

As far as the scope output, you are likely picking up the RF transmissions on the servo itself. All channels are output by the same CPU, so they should all look perfectly crisp. Turn off the EVO radio after a connection has occurred to see if there is a difference. You are using clip leads instead of scope probes, so those will pick up everything signal wise, and the servo itself could be the reason. If in doubt, plug the servo and check the output from the X10+ directly.

[erhard52]

The SRXL protocol used by the newer Spektrum receivers is not supported by the X10+.

As far as the scope output, you are likely picking up the RF transmissions on the servo itself.  All channels are output by the same CPU, so they should all look perfectly crisp.  Turn off the EVO radio after a connection has occurred to see if there is a difference.  You are using clip leads instead of scope probes, so those will pick up everything signal wise, and the servo itself could be the reason.  If in doubt, plug the servo and check the output from the X10+ directly.

thanks for the reply and thanks for the clarification on the SRXL protocol.

ok maybe i was not clear in my description - i did this, i probed the channel output on channel 1 (the clean one) with and without servo - same thing, signal looked crips and i did the same thing on many other channels - same thing it always looked bad. it also did not matter where i fed in the ESC 5V connector. no matter what i did the channel 1 looked good and all others bad.

i agree the unshielded clips is not perfect but in this case it did not seem to matter - but yes i also can probe with the scope probe directly.
as i said i will try another X10 and also another receiver from radiomaster or spektrum.

[erhard52]

The RFU is actually -107dBm in a controlled test.

You should be able to turn on/off the transmitter and if the failsafe is really set to HOLD last position (and not USER defined) then the servos should stay put.  You should not see any amount of movement.  Unless you deliberately changed the RFU's settings the failsafe defaults to USER defined with preset positions at 1500us.  It is recommended that you do the live-active failsafe setup.  You do that by powering on your system so you can move the servos and then press and HOLD the button on the RFU until the LED started flashing red/green.  You will have about 7 seconds to positions the sticks and switches on the transmitter where you want them during a failsafe condition.  Typically this will be all neutral sticks.  The purpose of failsafe is not to save your aircraft - it is to provide you with some insight of where the crash will most likely occur so that people can be moved out of the way.  We typically provide a small amount of up elevator and rudder to cause a deliberate spiral pattern during a failsafe condition.

The RFU works down to 2.1v, so the voltage level you are talking about will not affect it.

great inside as usual - thanks a lot
the more i am looking into different RC systems the better the XPS system looks . how could it have disappeared? i listened to the AI story and the Graupner (i am german and that i why i love my multiplex EVO) issues - too bad this happened.

i did not change the failsafe conditions and subsequent power off tests dis not show the movement. 

anyways one last question (that could be a lie) - do you think i should be able to make the Spektrum SRXL2 DSMX Remote Serial Telemetry Receiver, SPM4651T work with the x10+ v2?
i did spend hours and it did not work. i programmed the x10 to input mode 3 flashes and tried all 4 binding modes to no avail. the SPM4651T was bound to my tx16s with DSMX protocol.

here a link to my various attempts
https://1drv.ms/w/c/9dc6d60a8cb4c333/IQD...E?e=zRuVze

here comes bonus contribution.
i scoped the X10 signals and other than channel one all look really bad
https://photos.app.goo.gl/Pex23SwM2HYKaFZq6

CORRECTION and apology!
please again take a look at the link with the scoping signals. all looks good. it was my fault to work with uncalibrated scope probes.

[erhard52]

has anyone any idea on how to make the archer plus GR8 receiver output regular SBUS signals?
i cannot connect it to my SBUS XPS X10 channel expander

ok problem solved - the right connection on the archer plus GR8 is the SBUS.out pin next to CH8. now it connects to the X10+ when set to Futaba SBUS - 2 flashes. in my case where i tried to connect a radiomaster TX16S to the x10 i needed to update the FW in the 4-in-1 radiomaster module and the latest in the transmitter (as of march 2026)
so that allows one to keep the XPS x10+ wired up to the servos and only replace the receiver. the GR8 has a built-in barometer which is nice for glider flying. today i flew about 500ft (135m) up and had no issues with the telemetry .

i still wish i had a spektrum module for the EVO 12. to me that is one of the most ergonomic transmitters. even the screen is a simple LCD screen it is at the front of the transmitter and not blocked by the necklace band.
bottom line is it seems that the x10++ works well with SBUS receivers in general.

[erhard52]

here more news. i learnt how to use the 4in1 module in the radiomaster TX16S.
radiomaster has many receivers with SBUS which can be connected to the X10. here my latest issues with X10 v1 - x10 v2 works (almost)

connect RadioMaster R86C (has SBUS) to XPS X10v1
set to futaba SBUS makes X10 LED green but the moment i add a servo it turns yellow and the servo jitters all the time and does not react to the transmitter stick.
also this X10v1 cannot be set to higher flashes than 5.
it seems this X10v1 has really old FW.

however, connecting to the R86C to the X10v2 works the servo but still the X10 LED turns yellow the moment the servo is connected. what does that mean - the voltage is ok.

[flyingw]

Hi Erhard,

There may be two problems happening here.

First, the power source may not be working properly.  The X10 manuals (both v1 and v2) both say that when the power supply goes from 4.01 to 4.5 volts the led will turn yellow.

Second, are you using S-FHSS in your 4in1 module?  If you were using FrSky D8 or D16 then the frame rates with those protocols are incompatible with SBUS and servo operation will be erratic.

[erhard52]

Hi Erhard,

There may be two problems happening here.

First, the power source may not be working properly.  The X10 manuals (both v1 and v2) both say that when the power supply goes from 4.01 to 4.5 volts the led will turn yellow.

Second, are you using S-FHSS in your 4in1 module?  If you were using FrSky D8 or D16 then the frame rates with those protocols are incompatible with SBUS and servo operation will be erratic.

thanks, right!
update (all good):
-servo works now on  x10 v1. i had to change the protocol to
MULTI FRSKY X D16 and turn telemetry OFF. before it was FrSky D8.
still the x10 LED turns yellow the moment i operate the servo

- also the turning to yellow LED was really due to low voltage - 
after replacing the battery LED stayed green. so X10 worked as advertised and is really sensitive to small voltage drops

GOOD NEWS: radiomaster receivers with SBUS work with XPS X10+ v1 and v2!

i just checked out that the Futaba S-FHSS protocol also works

thanks again
erhard

PS.: it still seems the v2 version is more robust because it worked fine in all modes whereas the v1 struggled in one

[erhard52]

Hi Erhard,

There may be two problems happening here.

First, the power source may not be working properly.  The X10 manuals (both v1 and v2) both say that when the power supply goes from 4.01 to 4.5 volts the led will turn yellow.

Second, are you using S-FHSS in your 4in1 module?  If you were using FrSky D8 or D16 then the frame rates with those protocols are incompatible with SBUS and servo operation will be erratic.

thanks, right!
update (all good):
-servo works now on  x10 v1. i had to change the protocol to
MULTI FRSKY X D16 and turn telemetry OFF. before it was FrSky D8.
still the x10 LED turns yellow the moment i operate the servo

- also the turning to yellow LED was really due to low voltage - 
after replacing the battery LED stayed green. so X10 worked as advertised and is really sensitive to small voltage drops

GOOD NEWS: radiomaster receivers with SBUS work with XPS X10+ v1 and v2!

i just checked out that the Futaba S-FHSS protocol also works

thanks again
erhard

PS.: it still seems the v2 version is more robust because it worked fine in all modes whereas the v1 struggled in one

btw thanks for your continued very helpful input and
 Happy Easter