more problems with my spektrum

[Martin Harris - Moderator]

Thanks WF - the stuff I've seen on the net about this seems rather confusing. I assume from your answer that different receivers behave in different ways? I'll see if I can confirm the type...

[WolstonFlyer]

It would be good to know the receiver model number. The light flashing twice could also be indicating that two "holds" have taken place, this is where the RX loses the signal from the TX rather than a loss of power making the RX reboot.

Going out of range because of pressing that range check button would cause a " hold", also perhaps the TX battery being low or a fault with the TX such as the antenna wire inside coming off the RF board... my DX6i did that and it seemed to range check OK.

[Martin Harris - Moderator]

Hmm - I did do a failsafe check before flying - can't recall whether the receiver was switched off between that and the flight,,,that might account for at least one flash. From what I've read it seems that it works on a mismatch between the 2 channels selected when re-powering the transmitter being different from the original ones remembered by the receiver?

[Paul Marsh]

Flashing red LED indicates a voltage brownout. Really it is best to use good 6v batteries on all 2.4 installations, as most problems are battery related.

[Martin Harris - Moderator]

Posted by WolstonFlyer on 13/10/2013 00:12:38:

It would be good to know the receiver model number. The light flashing twice could also be indicating that two "holds" have taken place, this is where the RX loses the signal from the TX rather than a loss of power making the RX reboot.

Going out of range because of pressing that range check button would cause a " hold", also perhaps the TX battery being low or a fault with the TX such as the antenna wire inside coming off the RF board... my DX6i did that and it seemed to range check OK.

I've been advised that it was an AR600 - will this act the same as an AR500? I'm not familiar with the intricacies of Spektrum receivers...

Just to complicate matters, I did notice that switching the transmitter off and on again increased the flash rate to 3 then pause. Would this lean more towards a transmitter problem? I would have expected the failsafe (checked before flight) to have come in though, if that were the case and I'm certain the power stayed constant.

Oddly, I've found several references to similar problems mentioning similar problems when the model was at "11 o'clock" (at least I assume they don't mean late morning!) and guess where it was when the problem started?

Edited By Martin Harris on 14/10/2013 13:03:49

[Bandit]

There isnt any carbon in the model the antenna could have touched is there?

[Martin McIntosh]

I bought a JR DSX9 Mk2 to supplement my Mk1 and put all of my best and newest models on it. It was only after five brown outs/crashes with different models that I realised it must be a Tx problem. In each case everything worked fine afterwards. Not sent in for repair yet but could never trust it again. If you see it on ebay don`t touch it. Never a twitch on the Mk1.

[Bandit]

I have to confess the only issue I ever had with my Spektrum gear was with an AR500 and a cheap indoor receiver.

The AR500 would loose reception for a small amount of time, but enough to make my heart skip a few beats, and the indoor one was just a dud cheap thing from e bay.

I think the AR500 needs the long lead to be placed at 90 degrees to the short lead/antenna to try get some diversity, but odly it happened twice and in the same place in the field each time.

But then I have hundereds of flights with cheap Orange receivers.

I know the feeling though, once you can't trust something, you just don't want to use it. But remember something has to be wrong because thousands use the same gear with no issues.

Cheap foam testbed time I'd say, maybe different receiver/ separate battery, only brown out I ever had was a dodgy esc stopped the power going to the receiver.

I know the 2.4ghz stuff is prone to browning out if the voltage gets too low, so if it is an IC with a NiMi have you a voltage indicator as if you wiggle the control surfaces sometimes if the battery is a bit old it goes to the red strait away, imagine what would be going on with load on the servos.

[Pete B]

This thread seemed to peter out in the middle of last month but has surfaced again, so, whilst far from being a Spektrum 'expert', it's worth trying to correct some of the apparent misapprehensions in some of the above posts.

The AR600 is different from the AR500 in that it has an additional red LED to the normal orange LED. Being one of the new generation of Spekky Rx's, capable of using the DSMX protocol as well as DSM2, it needs a method of indicating that a 'hold' has occurred, this not being possible on DSMX. A read of the AR600 guide explains it more.

If, after a flight, you find the red LED flashing, it is because a 'hold' has occurred, ie it has lost contact with the Tx for a period of time, as WF has pointed out. The number of flashes indicate the number of 'holds'.

On the other hand if, after a flight, the orange LED is flashing, this indicates that a loss of power to the Rx has occurred, ie a 'brownout'. If it is a momentary loss of power, the 'Quickconnect' facility will restore the link so fast that there's a good chance you won't notice it in flight.

As Martin observes above, switching off the Tx resulted in an additional 'hold' being indicated - it's doing exactly what is intended. That and a failsafe check would account for two 'holds' but not the third, if I read the above correctly.

I bought a JR DSX9 Mk2 to supplement my Mk1 and put all of my best and newest models on it. It was only after five brown outs/crashes with different models that I realised it must be a Tx problem. In each case everything worked fine afterwards.

Just to reiterate, no Tx problem has ever caused a 'brownout' - a 'brownout' is simply a loss of leccy power to the Rx, nothing to do with the radio side of things.

From what I've read it seems that it works on a mismatch between the 2 channels selected when re-powering the transmitter being different from the original ones remembered by the receiver?

As far as I understand it, on DSM2, if the Tx is switched off and then switched on again, it will try and regain a link using the last two frequencies it was transmitting on, thus re-establishing the link with the Rx.

Where does this leave us in summary, then?

If you are getting indications of 'brownout' then it is your Rx power supply that needs investigation.

If you are getting 'holds' indicated, it is an RF problem. My first port of call would be aerial placement - particularly with an Rx like the AR600 - used without a satellite, that short length of aerial could be less than optimally placed. Carbon in the model can have a significant impact on reception, too. If you're happy that all is well with the installation, then it's worth having a closer look at the Tx and perhaps send it in for checking.

Just my 2p worth, so I'm quite happy to stand corrected!

Pete

[Martin Harris - Moderator]

Thanks Pete - that certainly sums up my appreciation of the situation and operation of the system. I did some more tests earlier today before returning the gear to the owner with the recommendation to send it to HH for checking - great minds think alike?

There's no suggestion of CF anywhere in the model and I did some tests earlier with the aerial being pointed at the receiver - at a similar distance to where the problem started - I was unable to lose the link when aligning both receiver aerials with the transmitter aerial. I did lose it when putting my body in line with them but the behaviour was entirely as expected - throttle servo went to failsafe, the others stayed where they were and the red light flashed per interruption. Reconnection was almost instantaneous when I moved out of line.

As the throttle didn't budge when I lost control of the model, I'm sure it wasn't a loss of transmission and I don't recall any tell-tales from the orange LED.

What makes this even more worrying is that the owner builds from kits and plans so there is a considerable amount of effort going in to his models which makes the loss of one of far more consequence than if it was an ARTF - especially as he only has one arm! When I went round with his gear earlier, he showed me the substantially repaired fuselage and was in the process of shaping a stack of wing ribs for a new wing he's drawn up to replace the foam original. Try thinking about how you would approach these tasks with one hand...