2.4 problems?

[chris williams]

Just received this...is this a known issue?



I’m not sure if you’re aware but I had a radio problem at TH last week, which had the aircraft been airborne would have resulted in a complete loss of control and subsequent crash.

I had been flying a small electric aircraft using a Futaba 14SG transmitter and an FrSky FASST compatible receiver. No problems, green light on the receiver and aircraft behaving normally. However, just before I launched for my next flight another flyer switched on his transmitter whereupon I lost the link with my receiver. The servos went to their linear limits and froze.

Suspecting a dodgy transmitter I waited until the gentleman had left and tried again – everything fine.

I called Ripmax the following morning to find out what could have caused the problem (isn’t 2.4 bombproof?) – only to learn it’s a known situation.

Apparently, the EU introduced new regs. for 2.4 last year. Futaba brought out an update to their software to accommodate the new requirements, but in doing so, made non-futaba receivers incompatible with Futaba FASST transmissions.

Anyone using a new Futaba transmitter or with software at level 6 or later will have this problem – not good!

I’ve since tried using Multiplex and Spektrum transmitters (neither use FASST) both broke the link. Seems any 2.4 ghz transmitter will do it.

Particularly worrying as the non-futaba receiver will appear to bind correctly and function as normal, but the link is not secure. Anyone switching on a 2.4 transmitter nearby will shoot you down

Although aware of the problem, Futaba/Ripmax have not made any announcement – they don’t consider it their problem ‘if you stick with genuine Futaba radios you’re safe’ – so it seems it’s up to us to spread the word.

[FrankS]

Chris

It's old news and FRSKY did release an update for their Futaba compatible receivers a few months after which addressed the problem. But at the time Frsky were also caught out with their own EU protocol which wasn't fixed until they updated to LBT.

Some sympathy with Futaba the Frsky stuff was not licensed from Futaba but reverse engineered, so they can't be responsible if they do an update which works with all their own stuff, it's upto the "clone" manufacturers to make sure they address any issues. I can't recall if Frsky made any announcement when the problem came to their attention either.

[chris williams]

Ah, that's me...always the last to know

[eric friend]

When I upgraded from my Robbe FC-18 to Futaba 14SG a couple of years ago, I found that the FrSky FASST receivers I had been using quite happily now wouldn't work with the14SG. On investigating, I found that there was an issue with the FrSky receivers in that mine just wouldn't work correctly after being bound to the newly acquired 14SG; they were very unstable, even on Version 5 software.
On googling the problem, I learnt that an upgrade for the FrSky receivers was available, but until positive feedback on the software updates was forthcoming, I decided to stay with Futaba receivers.
Presently I operate solely Futaba receivers with my 14SG. I have a number of FrSky receivers awaiting their software upgrade and should I want to fly the models they are installed in, then it's back to the trusty FC-18.

[Simon WS]

This is only if your transmitter software is 6 and above right? My FX20 (which is really a Futaba 8FG transmitter in big boys clothes) is on 5.1 level software so I don't think I have the problem?...

Simon

[FrankS]

This is only if your transmitter software is 6 and above right? My FX20 (which is really a Futaba 8FG transmitter in big boys clothes) is on 5.1 level software so I don't think I have the problem?...

Simon

Simon if the Frsky Fasst rx has the latest firmware (i.e. bought after mid 2015 or updated) then it works with all current versions of Fasst, as long as you have the correct modulation selected on your Tx. Friend has an earlier 10cg with the futaba 2.4 module which is certainly the earlier firmware and later Frsky receivers work just fine. Problem would be if you managed to buy some older Frsky Fasst rxs which hadn't been updated and were using the latest Futaba firmware on the Tx.

[Simon WS]

You didn't seem to have any problems flying your new K6 over the weekend Simon.

True enough Cliff, but I started to get paranoid on reading Chris's thread! BTW I gave the K6 a major workout on a windy slope yesterday and can report it loops AND rolls!!

Thanks Frank. I'm in the situation of having older Frsky receivers AND the older transmitter software - I have no desire to update either of them to be honest so I guess I will stay with that set up unless I'm forced to change. I take it "upgrading" to version 6 of the Tx software doesn't give any functional advantages?

Simon

[FrankS]

From a transmission perspective it was done to tighten the EU specifications and lower the risk of the transmitter causing interference to others, so no benefit from that point of view. I think on the 14sg the update also included some Tx/telemetry enhancements so if you had the earlier 14sg and did the update then Frsky FASST on the earlier firmware could be problematic.

[eric friend]

Simon,
I have checked the specs for upgrade Versions 6 and 7 and the changes are mainly to do with telemetry as FrankS says, and a little related to airbrake and camber mixing - however there is nothing that your FX20 can't live without. In fact, Version 5 has brought the best range of improvements to your system.
I will need to upgrade my 14SG to Version 7 as I have purchased the latest Futaba Altitude Sensor and that needs Version 7 for it to be displayed in the appropriate menu on the transmitter.
Cheers,
Eric

[Simon WS]

Thanks Eric, I love it when I don't have to do anything!
Now, have you got your ASH25 ready for Middle Wallop?!..

Si