taranis x9d internal & external xjt module low rssi issue

General Help and support for the Taranis Radio.
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PVDF
Posts: 2
Joined: Wed Dec 27, 2017 3:54 am
Country: Korea, Republic of

taranis x9d internal & external xjt module low rssi issue

Post by PVDF »

hello.
finally i just got rssi problems that already many persons have experianced.

<my equipment>
Transmitter: taranis x9d original(not plus)
Receiver : XSR or D4R-II
VTX : eachine vtxx03 200mw

before rssi problem occur, i have never heard "rssi low" and "rssi critical" voice.
rssi value was almost 95~105 and swr value is always zero.
all problems came suddenly!



so, i have had some test (not range test mode in taranis menu)

(1) range vs rssi test

--> with XSR rssi value : 3meter 80~85 , 100meter 70~75
--> with D4R-ii rssi value : 3meter 80~85 , 100meter 70~75

(2) replaced taranis stock antenna to new stock antenna (2db antenna)


--> with XSR rssi value : 3meter 80~85 , 100meter 70~75 (almost same with old antenna)
--> with D4R-ii rssi value : 3meter 95~100 , 100meter 70~75 (rssi drop ratio is high!! drop fast!!)


(4) use external xjt module (got from banggood)

--> with XSR rssi value : 3meter 80~85 , 100meter 70~75 & SWR is 33 !!!
--> with D4R-ii rssi value : 3meter 80~85 , 100meter 70~75 & SWR is 33 !!!

I really really perfectly disappoint about external module, because i thought those all low rssi problems cames from tx module!!.




In this situation, what more should I try to solve the problem ??
A power module defect in taranis backboard can cause rssi problems?
some firmware mismatch can cause this?

Any help would be appreciated. Thanks and happy new year.

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bob195558
Posts: 2377
Joined: Sun Dec 16, 2012 7:24 pm
Country: United States
Location: New England, Vermont
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Re: taranis x9d internal & external xjt module low rssi issue

Post by bob195558 »

Hi PVDF,
Looks like the collection of your test data, was done well.
Could try each of your 2db antennas.
Not every antenna are made exactly the same.
May want to look at buying more test equipment:
(http://www.immersionrc.com/downloads/ma ... Manual.pdf),
(https://www.hobbyking.com/hobbyking/sto ... duct=51616),
(http://j3.rf-explorer.com/40-rfe/articl ... cification).

Some more INFO

How do Antennas work ? :[/u] (https://www.youtube.com/watch?v=fSoXIqBlg9M&t=610s).
Antenna theory: The FrSky receiver antenna puzzle (part 1): (https://www.youtube.com/watch?v=WBE_KqqHbM0&t=183s),
(https://www.youtube.com/watch?v=xCVd3QGQhKU).
More info about spectrum analyzers: (https://www.youtube.com/watch?v=19JNDCVHaQQ)
and (https://en.wikipedia.org/wiki/Radio_spectrum).
Why I modified the antenna on my 2.4GHz RC radio: (https://www.youtube.com/watch?time_cont ... nK3HGzdmTc).
CP omnis near ground = Increased gain ?: (https://www.youtube.com/watch?v=ej3_kZ5zi1I).
(https://www.youtube.com/watch?v=1NXFps7ZIlg)
Testing Home Made 5.8ghz Antennas: (https://www.youtube.com/watch?v=jlz8MTTntGI).
(https://www.youtube.com/watch?v=oiBi9RbNBUY) (https://www.youtube.com/watch?v=PPKEpJEt_cM&t=127)
Directional Antenna find lost model: (viewtopic.php?f=45&t=10466),
GPS Racing Discussion: (https://www.rcgroups.com/forums/showthr ... Discussion)
FrSky GPS 10Hz firmware: (https://www.rcgroups.com/forums/showthr ... z-firmware).

There was a change that FrSky did at some point with the internal XJT module when the Taranis-x9d were being made.
But have not seen where it has been a cause to a problem, though they did do a change which I do not know why they did the change.
Did have a problem with one or two of the Taranis-x9d internal XJT module randomly malfunctioning.
The fix was warranty replace internal XJT module.
But your data looks to not be a defective internal / external XJT module.
Most of my testing, the external XJT module works better, but your data shows they are the same.

Firmware mismatch is normally between Euro firmware and the rest of the world (normal firmware),
which you would not be able to make bind between the TX and RX.

Hope this maybe of some help.

Bob B.
Er9x on 9x radio, with Smartieparts Programmer and TelemetrEZ Board.
ErSky9x on Taranis, Sky9x, 9Xtreme radios.
3D-Printing: (https://openrcforums.com/forum/viewforum.php?f=129).
PVDF
Posts: 2
Joined: Wed Dec 27, 2017 3:54 am
Country: Korea, Republic of

Re: taranis x9d internal & external xjt module low rssi issue

Post by PVDF »

thank you so much.
I think carefully that my taranis x9d has problem with power board. Not internal or external module like you mentioned.
I'll try something different.
if i solve this problem i'll reply.

And one more question.
Why my new external module's SWR value get 30~33 ? I think it's not normal.
Is it defective one? Should i return this to seller ?
Or need to some DIY generally?

thank you.
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jhsa
Posts: 19480
Joined: Tue Dec 27, 2011 5:13 pm
Country: Germany

Re: taranis x9d internal & external xjt module low rssi issue

Post by jhsa »

High SWR might mean a bad antenna. Try replacring the antenna with another one.
Also check that the radio and antenna have matching plugs. One should be male, and the other female...

João

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