Is there a problem with the DX6

[gangster]

Posted by Martin McIntosh on 12/03/2017 17:14:33:

I cringe when I see newbies with theirs pointing sideways, just asking for trouble.

I am interested to know your reasons on that that Martin.

My thoughts 0n that are

1, I cringe when I see modellers, new and old twisting their aerials round every time they get the tx out, that can and does end in tears, causing damage to the base, the the connection.

2, Minimises the loss caused by pointing the TX to the model indeed it is necessary to follow the model. I believe ,although on 2.4,any loss that pointing at the model is only momentary on a moving model anyway . Cross polarisation and radiation pattern losses are surely more significant on 35MHz

3 If the RX aerials are oriontated in a slant position at about 90 degrees it has to give one of them a fighting chance of a good signal. Any effect of proximity to the case is minimal

4 I believe that is exactly how Futaba set up the in built aerials on the J series.

5 For all of the above reasons I have always set my Spektrum TX aerial in that oriontation and not had a scary second.

Happy to be corrected on any of those points, and anyway it looks like the manufactures have seen the light and have moved away from those horrible weak twiddly TX aerials

[Martin McIntosh]

If you look at the radiation pattern from a single aerial you will see that it is zero when viewed directly down from the tip, therefore if it is pointing directly sideways there can be no received signal at the model when it is flying straight towards (away from) the tip no matter what or how many aerials are installed. This is exactly the same as 35mHz.

Thought everyone knew that.

I don`t like to keep moving the aerial either but having examined one after very much use there was no sign of damage.

We used to replace 35 mHz ones when they got a bit tatty so if you are worried you could always do it to a 2.4.

Multiple Tx aerials will of course correct these problems.

[gangster]

Hmmm yes all well in theory but of course models move in three dimensions and we can imagine a number of scenarios where a null or cross polarised signal might be received. A definite argument for multiple tx aerials. However we are talking short range fpv apart and problems with single aerials are aparantly rare

[MattyB]

Posted by Martin McIntosh on 13/03/2017 10:43:48:

If you look at the radiation pattern from a single aerial you will see that it is zero when viewed directly down from the tip, therefore if it is pointing directly sideways there can be no received signal at the model when it is flying straight towards (away from) the tip no matter what or how many aerials are installed. This is exactly the same as 35mHz.

Thought everyone knew that.

We do, but do you or anyone you know regularly stand at 90 degrees to the flightline, flying over their own shoulder with the tip of the aerial pointed out towards the model? I've never seen that, but that is the only use case I can think of for LOS fixed wing flying where an aerial on it's side would be at a substantial disadvantage. I do however fly some of my thermal gliders very high, sometimes directly overhead, and in that instance a sideways orientation is far superior to one in a vertical. Conversely FPV racing pilots tend to orient their TX and RX aerials in the vertical plane as they need wide, flat propagation of the signal as they will not be flying high nor turning their bodies to face the model as it flies.

In summary there is no hard and fast "right" answer - it's horses for courses. The only thing that is categorically correct is to think about the type of pattern that particular model is going to fly, then orientate your aerials to give best performance for that pattern. For the models I fly that means everything in the horizontal plane, and I have never had any issues in ~6 years of flying 2.4Ghz systems with inbuilt signal strength telemetry.

[Phil Green]

Posted by Martin McIntosh on 13/03/2017 10:43:48:

Thought everyone knew that.

I think everyone is well aware of the theoretical donut pattern Martin, many of us are hams and RF techs - but that principle applies to ideal conditions ie an isotropic chamber, in practice there is so much reflection and scatter that the radiation pattern isnt anywhere near as theoretically perfect as some expect.
Like many others I've often deliberately pointed the aerial at the model and even at extreme distance with single-aerial receivers, I've never managed to deliberately cause a failsafe event.
Matts approach is the right one, ie to continually take account of the immediate circumstances rather than blindly doing this or that just because you always have done.

/2p
Phil

[PETER BRUCE - Eastchurch Gap]

Hi all. Been following the thread and one feature not mentioned here is that the higher in frequency you go the more line of sight the signal tends to travel and the smaller the aerial becomes.... When your Rx is fitted into your plane at certain orientations with the ground Tx the signal may have an obstruction which will block or cause attenuation (see below) to the radio signal - like a nice big petrol engine, battery pack, fuel tank - you get the drift. Hence the opportunity to provide another "clear" signal path is preferable. Another factor perhaps of interest at higher rf frequencies is that the difference between vertical and horizontal polarisation becomes more important and thus if you think of your Sky satellite dish the block converter on the front of the dish - with the cable coming out - can be turned to pick up either a vertical polarised channel or a horizontally polarised channel yet both orientations will pick up a satellite channel which is transmitting on the SAME FREQUENCY however the attenuation you get on the signal from horizontal to vertical polarisation equates to around 20dB which is why having two aerials aligned in two planes (forgive the pun) is a good idea. I do however feel that two aerials being used on the Tx is also important and as we are only really on first generation 2.4 gear = "watch this space" - and re-spend your money again...

Gone are the simple days...

[Phil Green]

Posted by PETER BRUCE - Eastchurch Gap on 13/03/2017 14:58:47:

Hi all. Been following the thread and one feature not mentioned here

Thats been mentioned many, many times Peter almost as ubiquitous as the donut diagram

[PETER BRUCE - Eastchurch Gap]

OK Phil - stand corrected but I hope the explanation helped a few anyway... Regards Peter

[Denis Watkins]

It is worth repeating Peter, as it is a soon forgotten 2.4 gig issue

Attached to all makes, and novices too read the column

[gangster]

The message here has to be that our radios are relatively cheap consumer items. They are designed to be switched on and used. All makes are good if treated properly. All we need to understand is the need to keep those receive aerials in the clear

[Phil Green]

from yesterday:

Posted by Goldguy (RCG) on 15/03/2017 05:30:00:

DX6 WARNING!!
I was sloping over the ocean the other day and my DX6 G2 went dead,
with my bird ending up in the SALT chuck. Apparently, 'permanent' loss
of transmission is a common problem and the fix is warranty return.
Good thing I wasn't flying a 1/4 scale war bird at the club field full
of slow moving old guys. Wonder what kind of a law suit that would incur?

[Denis Watkins]

"Ocean" suggests USA

"Dead" = Dead flight pack

Best advice is not to fly over old folk

And check your flight pack

[Don Fry]

Phil can I take you gently to task. You repeat an entry from a foreign site, posted by a bloke we know nothing of, never heard of before and who I suspect you don't know. He is also talking about a quarter scale warbirds. In my experience a DX 6 would struggle to operate such a machine, not enough channels for the chunky serves needed. So that comment seems to me, shoved in for dramatic effect, or he is in fantasy land.

As Denis points out the post says nothing, apart from following a tradition being set up by their new President, say something controversial, get everyone talking about it, and then call for an enquiry because people are talking about it.

I use Spectrum. I don't care much if is exposed as rubbish or not. I can move somwhere else, or stay. But I am interested in reasoned argument, and posts repeating posts with no factual content, merely an accusation does not move that argument forward.

I apologise if this upsets. But I am a thick skinned old fart. Remember newbies read this thread.

[Phil Green]

Donald, the thread title asks "Is there a problem with the DX6" and since it is posted on a public forum rather than directly to Horizon Hobby, I assumed it was open for discussion and that a recent report from a highly respected member of RCG might be of interest. Actually Frank (Goldguy) is well known to many of us (in the net sense), he designed the Nutball and is a keen slope soarer and a regular contributor to Den's Wisel thread. That you personally dont know of him is by the bye, and your loss. If Frank posts something, it is factual, he's that kind of bloke. He is also not an idiot Denis. Maybe you both prefer to read the genuinely misleading technobabble nonsense posted in previous Spektrum threads by people who have no clue how it actually works. Yes you've upset me by accusing me of posting an untruth and deliberately misleading newbies. The vast majority of my posts are intended to help within my narrow area of expertise. And whilst I accept your apology, I'm done here.

Edit: just confirmed with Frank, the Tx has failed, nothing to do with flight packs.

 

 

Edited By Phil Green on 15/03/2017 18:59:03

[Don Fry]

Fair enough Phil, but the poster still does not give any information on the post. Therefore the argument is not advanced.

[Denis Watkins]

If I could retract my post Phil, then I would, as it was general comment, and non personal

Fly with me over the summer, and see the real me

[Don Fry]

Edit: just confirmed with Frank, the Tx has failed, nothing to do with flight packs.

So why did he not say so in the first place. And we are still without any information as to what the failure was. But as you say I am also out of here until the argument improves.

[Phil Green]

This is my last Donald, I have no idea why you continually seek an argument, I dont, and I doubt that 'Rocker' did either when he asked the question "Is there a problem with the DX6". Surely in his thread, the decision as to what constitutes a useful reply is his, not yours. If I were asking the question, I would appreciate reports good and bad.
As for "So why did he [Frank] not say so in the first place" can you explain to me where in Frank's phrase "my DX6 G2 went dead" there is any doubt as to what happened to his DX6 G2? and "without any information as to what the failure was" ? He doesnt yet know what the failure is, he's not an RF tech. It has power, but its dead. I'm astonished by your attitude Donald, this isnt your thread, this is about 'Rocker' asking for answers to his question. Why you want any argument, let alone an 'improved argument' is utterly beyond me. Thats my last.

 

 

Edited By Phil Green on 15/03/2017 20:59:05

[Don Fry]

An argument is an exchange of views and logic, not shouting at each other. We are now shouting. May your propellor remain unbroken.

[Geoff Hoolahan]

Hi, hope nobody minds if I add a post in response to the original question 'is there a problem with the DX6?'

I bought a DX6 some time last year, G2 6700 (so single antenna version). Then reading about potential problems, I was reluctant to trust it with my main fixed wing models, so it became the 'sim' transmitter'. A bit of a waste really.

Then this year I noticed that HH re-launched the Champ, an old favourite of mine, but this time with lots of new features including gyros, GPS, and failsafe features like 'holding pattern' 'geo fencing' and 'auto landing'. So I thought, this is the ideal plane to give me confidence in my DX6.

Took it out yesterday, ground checks, range checks all fine. Take off was fine, once above about 20 feet the DX6 had no control whatsoever. The Champ went into its holding pattern, flying circles over my head. None of the Tx buttons or functions seemed to have any effect; most significantly I could not reduce the throttle. The Champ eventually 'auto landed'.

Today, I re-bound the Champ to my main flying transmitter (DX7s), went back to the same flying area and it behaved impeccably; smooth flying in circles, figure of 8's, well over 10 minutes of flying and 3 interim landings.

Conclusive - probably not.

Would I ever trust the DX6 - definitely not.

What can I do with it? probably take it to the local tip. Pity really, it's so smart in its black and red livery

[MattyB]

You could try returning it to HH... then again, maybe not!

[kc]

Taking it to the tip is surely the worst thing you could do! It would likely be found by the eagle eyed tip attendants and find it's way to ebay to cause the same problem with some unsuspecting buyer.

Better to find the real cause of the problem by further testing ( without risking a plane) or to send back to the dealer to return to Horizon Hobby.

[Stephen Smith 14]

Best cure I found for problems with Spektrum gear was Hitec

[Denis Watkins]

Best cure I found for Spekrum gear was to fully charge it

And not to fly park flyers with it, that had limited range, and

Are known for loosing GPS, and for loosing their bind

Am just looking at the whole story

Edited By Denis Watkins on 19/04/2017 20:59:28