X9d+ range problem

[trebor]

Well I sold all my Spektrum gear and now I'm getting range warnings on Frsky and loss of signal with two planes down at about 120 yards just off the edge of our patch maybe 50 - 100 feet high. One plane went last week with a signal loss warning given out of the tx and now again today but it recovered just before I hit the ground along with warnings given on lost signal alarm and signal recovered. Every thing seems fine batteries ok, range tests before were ok. Both planes were electric one with x4r the other with x6r Rx's. I did fly over the same spot again as I'm a bit of an idiot but nothing happened, I got a Rssi signal strength of 55 - 65 at 100 yards ? Is this bad ?

[Allan Bennett]

I don't know about the RSSI numbers, but is there anything in your models that could be preventing the antennae from functioning properly? I'm thinking of carbon fibre skin or reinforcement, or metal pushrods or other cables; the antennae must be positioned at right-angles to each other and, preferably, clear of and at right angles to any other conductors (i.e. carbon or metal). With a complete carbon skin the antennae must protrude through the skin.

[Denis Watkins]

This happened recently at our field Trebor, with control dropping in and out of a 2.4gig model,

But upon landing we found the chappie had set his C of G correctly, by strapping a sheet of lead to his RX nihm pack

And this was placed vertically against a front bulkhead

Of course this provided a convenient signal shadow with each circuit in the air

[trebor]

I wish it were that simple, one model is my old Funcub which has no carbon rods. Its mostly plastic and foam, the other model is a profile 3d foamy with a small amount of carbon in it both models were fine last year. This is a problem thats slowly getting worse. Both models have one antenna vertical and one horizontal It just feels like its the tx but I cant really be sure.

Whilst googling I did find this **LINK** which gave me an interesting read but this was around 2015 and I just found out my tx has just run out of warranty purchased Feb 2017 probably wont be the same problem

[Bob Cotsford]

2015 sounds like early LBT which was fixed with an XJT update iirc in late 2015. Do you have someone with a known good rx that you could try a range check with as a comparison with your own? RSSI of 55 is still quite good, the low alarm is set at 42 by default and even that level is safe, I can't remember what critical level is but I think it's down in the 30s.

One point that I found a weak link is the aerial lead in the transmitter as it can suffer from fatigue if you like to fold and unfold the aerial.

ps - I think it takes pretty much a complete loss of reception to trigger the receiver aerial diversity to swap aerials. I think Phil Green tested them properly years ago and determined that diversity was active so don't give too much credence to those posts where the guy claims one aerial is a dummy!

[trebor]

Frsky are a bit thin on the ground at my club, I have other rx`s but i found it strange Im getting the same problem on two different rx`s. I am really glad it was the foamys which took a tumble and not any balsa planes. Might just send it off for a check over as I am out of action now. Dont want to buy another Frsky tx until this has been resolved, that x10 looks nice but not now. Started with Spektrum now Frsky problems could force me to Futaba

[Former Member]

[This posting has been removed]

[Frank Skilbeck]

I thought RSSI was the signal strength at the receiver reported back by the telemetry.

[Chris Bott - Moderator]

I agree with Frank. RSSI is the received signal strength at the receiver, reported back via telemetry.

[Former Member]

[This posting has been removed]

[Geoff S]

RSSI (Received Signal Strength Indicator) is the received signal strength transmitted back by the receiver's telemetry which is, I think what Andrew intended and as both Chris and Frank wrote.

I've been using Frsky ever since I gave it a try with a Futaba compatible plug in on my old FF7 Super and following that with a DiY module I fitted to my Multipex 3030. I was an early adopter of a Taranis X9D which I've now replaced with an X10 Horus. I've never had a moment's worry that signal strength was low. In fact even the little 4 channel receivers which don't have telemetry work perfectly until the model is out of sight (don't ask but it wasn't a transmitter/receiver fault!) I do recall once having a RSSI low warning with a model quite far away and facing me but it was momentary and I never got the message again.

In my experience Frsky is as solid as a solid thing. I can only think that, as Bob suggested, it's an example of the problem some releases of LBT protocol which reportedly caused problems a few years ago but were cleared up with later releases. I didn't adopt LBT protocols until I bought my Horus earlier this year so I have no direct knowledge of the early problems.

I suggest you check which RF version is in the XJT module and download the latest version if it's old.

Geoff

[Rich too]

Posted by Denis Watkins on 26/06/2018 20:45:47:

This happened recently at our field Trebor, with control dropping in and out of a 2.4gig model,

But upon landing we found the chappie had set his C of G correctly, by strapping a sheet of lead to his RX nihm pack

And this was placed vertically against a front bulkhead

Of course this provided a convenient signal shadow with each circuit in the air

[trebor]

Geoff, I did update it when I first got it to version 2.1.9 then I've left it alone. I have never even used companion yet as I wanted to fully understand using the tx first. As for the Rx's I just use them out of the box not sure I want to mess with things too much. As I have mentioned it was ok up till now so somthing has changed and it's not been me fiddling with it. I usually fiddle with stuff and cause problems but not this time.

Edited By trebor on 27/06/2018 07:16:47

[Chris Bott - Moderator]

Trebor the symptoms, as described, point towards a hardware fault in the transmitter. It is apparent with two of (all of?) your receivers and it was OK before but isn't now.
I'd be comparing the range alongside another transmitter and other receivers.
But if you can't do that, maybe you should explore servicing options? Would T9 Hobbysport look at it for you, perhaps? PS. The RF firmware is a different thing to the version of OpenTx that you have.

Edited By Chris Bott - Moderator on 27/06/2018 08:17:07

[Peter Christy]

Trebor, you are confusing the OpenTx part of the system with the RF firmware. OpenTx (2.1.9 in your case) just does the encoding of the signal and has nothing to do with the RF boards.

As far as I'm aware, there's no way of "reading" the current RF version. You just have to flash it with a known source file (available from FrSky's website).

Later versions of OpenTx allow you to do this from the transmitter. You have to put the file on the SD card, and then you can go into the bootloader and it will flash the RF board for you. You can also update the Rxs from the TX, though it involves making up a special lead (not difficult).

As long as you upgraded the bootloader at the same time as you upgraded to 2.1.9, you should be able to do this. There are several guides out on t'internet, here's one:

**LINK**

Scroll down to "Alternative method via SD card". And here's how to do the Rx:

**LINK**

It may sound complicated, but once you've done it, it becomes very easy. Just MAKE SURE you select the correct firmware before flashing!!!

Its a good idea to try and keep the receivers and transmitter on the same firmware. Indeed they won't work if one is on "international" and the other on "EU / LBT"

Its something that's quite simple to do and check before committing to returning the Tx.

Best of luck!

--

Pete

[Peter Christy]

Chris: You posted while I was writing!

I agree it sounds like a hardware problem in the Tx, but its probably worth trying to upgrade the RF firmware before sending it back.

If Trebor isn't happy flashing it himself, I'm sure T9 would do it as part of the service.

--

Pete

[Biggles' Elder Brother - Moderator]

Trebor, you say you sold your Spekky stuff, was that just a decision to change brands or were you having range/signal issues with Spektrum as well?

BEB

[trebor]

My main reason for switching over was I had an early Dx6 with the single antenna and I had a habit of pointing it at the model, plus I feel the failsafes are better with Frsky and the cost is cheaper, I had just made a couple of quads and the choice of small rxs is great. I had no range issues at all with Spectrum.

I did take the back off the Tx last night just to check things over as I updated the sticks to Hall sensor gimbals but things seem ok, I couldnt see any problem with the antenna wire

Edited By trebor on 27/06/2018 09:49:18

[Bob Cotsford]

You won't see anything wrong with the aerial wire, at least I couldn't on mine, but pushing the aerial around triggered loss of signal.

Incidentally, my earlier LBT references were as a response to the linked comments in the first post, not Trebor's current problem.

[trebor]

I just had a look in a user manual and it says the Rssi signal should read 100 close to the transmiter but how close ? Too close and it fails. Then at a distance of 125 m it should give a Rssi reading of 60 so on Friday the next time I'm up the field I will experiment.

I will have a go to see the Swr signal is while I'm at it. For the cost of sending it back for testing and repair I could get a separate module to try first and just use that or I might even be tempted to replace the internal module myself.

[TigerOC]

trebor, It is worth using logging. I use the SF switch to arm my electric motors and to disable the throttle on an IC model. The same switch is used to start the log process. This will graph all your values with a time stamp. It is then really useful to go and examine the log file and check your RSSI values using Companion.

A large percentage of our club are Frsky users. We have had one member have range issues and that was due to a faulty RF board. It is a rock solid system. I recently had issues with a foamy but it turned out to be a dry joint in the XT connector on the ESC. So well worth while examining all the electrical components in the system. In this case I was using a non telemetry receiver but with telemetry glitches would have shown up in the Rx voltage.

Rob

[trebor]

You lost me with logging, do I need to buy somthing else to be able to do that ? I've had this set over a year and I'm still learning, there is more things to do on it than I really need

[MattyB]

No, no additional kit needed to log your RSSI values through the flight, just a single logical switch to setup or you can do it for all models by default...

[Allan Bennett]

That's a useful link MattyB I'm going to implement logging on my radio.

[trebor]

Well I ended up at the field checking over the Tx, nice sunny but windy day. The first 250 mtr test walk had me going down into a dip

so I tried another direction

At close up I got a Rssi reading of 91, in the book 100

at 125 mtr Rssi reading of 74, in the book 60

at 250 mtr Rssi reading of 51, in the book 54

at 300 mtr Rssi reading of 50, well in the book 500 mtr should be Rssi 48.

Now my telemetry started dropping out at 250 mtr and re connecting. At 300 mtr it was in and out but I still had control of my plane sat back on the field stand. My Swr reading never moved from 0 until I put my hand round it and then it only went to 12.

What do you think ? I gave up on walking 500 mtr as I would never fly that far away, I could only just make out my mate back at the field.