Corona DSSS problems

[jeffie8696]

But if the Corona doesnt scan the frequency before choosing to get you 3 clear channels then you could step on somebody.
But wouldnt all the transmitters at the field have to be turned on for it to scan the band and not choose ones in use?
I'm confused.

[coronarc.nz]

I'm a fellow flier like yourselves and have been flying on the Corona DSSS system for a year now - I liked it so much I started importing and selling it. As a result, I have had quite a few conversations with Bruce and other fliers who have bought from me. Most have had no issues, some DIY conversions have not worked well and I do not recommend converting the Futaba Attack 2ER transmitters as they are nasty and cheap - and just do not generate enough PPM strength to run the modules. Other problems I have come across seem to have been caused by faulty aerials on the transmitter - one just recently had a crack in the aerial casing and a section fell off. The flier wrapped it in insulation tape and kept going - only to have the model start locking up and eventually crash (softly) down wind. I sent him a new aerial, and he has retested, and so far all seems good.
With regard to the frequency scanning thing, it is my understanding that Corona's system does not change its operating frequencies under normal circumstances. So when you bind your receiver, the frequencies used by the transmitter are always the same. However, the proceedure that the Corona techies mentioned above DOES scan the frequencies active AT THE TIME YOU PRESS THE BUTTON and selects 3 new frequencies to work on - all of your previously bound receivers will need to be re-bound after performing this proceedure on the transmitter. (Just to re-cap, To carry out the scan and reselect frequencies proceedure, turn on the transmitter while pressing the bind button and keep the bind button pressed down for longer than 3 seconds, usually about 5-6 seconds will do. Wait a few moments and then power down your transmitter, then re-bind your receiver as necessary) NOTE: IF SOMEONE ELSE THEN TURNS ON THEIR 2.4 TRANSMITTER and it is on the same frequencies that your transmitter has just selected as being clear, then interferance is possible again..
Also Note: As stated in the manufacturer's instructions, certain man-made and other obsticles can also cause interferance on 2.4 systems, one of the worst offenders being long run wire fences (although I've never seen one jump up and snair any of my models, it doesn't mean that you won't find one that does...!)
I should point out that the DSSS sequencing and channel selection issues shouldn't just affect the one particular brand of system, as the problem is systemic since all the DSSS systems do not continually scan the spectrum and re-select workable clear frequencies. Where you may find a model is clear in one zone of a field, there may be interferance over on another corner of the field (say from a home wifi or similar) that the receiver may be able to "hear" but the transmitter cannot... long and short of it is, that the sooner the 5.8ghz systems come out, the better!

[jeffie8696]

Thanks for the help.
So when I do a bind the system checks the airwaves for anything else and only chooses 3 free channels.
But like some other systems it locks them in and only transmits on them even if one or more of the channels gets hit.
So the other systems that constantly change the channels and scan for interference then "go around it" so to speak are superior, but pricey.

[Roger]

So when I do a bind the system checks the airwaves for anything else and only chooses 3 free channels.
But like some other systems it locks them in and only transmits on them even if one or more of the channels gets hit.
So the other systems that constantly change the channels and scan for interference then "go around it" so to speak are superior, but pricey.

Not quite, when you do a "bind" for any system, it "trains" the receiver to recognise the transmitter that it is supposed to listen to. Bruce will correct me if I am wrong, but the Faast system uses LOTS of different frequencies, however I believe that it is still hoping in a pre-programmed squence over the whole spectrum. So I don't think that it will actually "Hop" away from an interferance laced part of the band, just that since it is using the whole range, you would never notice the section with interferance. The cheaper systems use less frequencies, Spectrum only use 2 (not that it is cheap by any means..!), Corona uses 3 as do quite a number of the others - Bruce's review on the 2.4 system details all this quite well.
Now, Corona's DSSS system WILL SCAN the band ONLY IF you perform the process I described in the post above, thereafter ever time you turn it on, it uses the SAME 3 frequencies that it has selected during the setting process OR the ones that it was pre-programmed with. Every time you bind a receiver, it tells the receiver the algorithim that the module is using to jump between and what frequencies to listen for. If you get interferance on any one of the bands, you should be fine because the system should be able to handle it, interferance on two bands should still be ok, but if you get a really really busy band (such as at an event with over 25 flyers all on 2.4 simultaneously then you may well have some difficulty and it is something that event organisers should be starting to pay some heed to. Bruce is certainly more of an expert on this than me, in fact I am repeating a lot of what he has said to me previously - but still, the more the information is spread the better eh!

[Roger]

I might point out, that I have NOT flown at really really busy meetings - however I have flown with at least 12 other gliders in a mass-combat event and had absolutely no radio issues. Not all of us were flying 2.4 though, and I am certain that none of the severly damaging crashes that followed were caused by radio failure.... (Pride damaging that is! ) While my experiences have been really good, I know of others who have nothing but scorn for the 2.4 systems - I could possibly point the finger at one major issues that all of the systems today are facing, at that is poor or non existant Quality control systems and cheap hand assembled components. To take and example, Futaba have built up a huge brand name in RC equipment, for one reason - they make quality components and do not compromise on their good stuff - and they take pride in their gear. Persoanally I don't mind paying a little more for the "good stuff" and so long as that message gets through to these Chinese manufacturing guys get what I mean by this we should start to see some really good products coming out of China more often. For instance if you tell them you want a $10 dollar receiver, they will make you a $10 one... with the cheapest parts they can find, if you say to them make me an 8 channel receiver with good performance, it might cost you $20 to $30 dollars, but you can gaurantee that they have spent more time and used better products to make it...

[Bart Doets]

In this video you can see a fellow clubmember of me, binding 2 transmitters to the same RX... he was using TX's that had been modified with new modules, that had not been reset yet:
http://www.youtube.com/watch?v=4dZ7h_Kn ... r_embedded

In post #7, I quoted a mail by Corona to one of my fellow clubmembers, where Corona suggested you could change the GUID by pressing the bind button on the TX >3 seconds.
But somebody else just tried this out on the Dutch http://www.modelbouwforum.nl. He wrote:

Pressed TX bindbutton >3 sec.; LED goes red, then blinks faster.
You'd expect the GUID to be changed now.
TX off.
TR on (no button pushed)
Result: connection.
My conclusion is, the GUID has not changed.
Next, following instructions, just after pressing the bind button on the TX, I pressed the button on the RX when switching it on. The thing works now normally.

Ne test: another RX, bound previously.
Even after several tries to change the GUID, the TX communicates with this RX normally.

[RCModelReviews]

I believe you have to hold the button down for at least 6 seconds to change the GUID -- or at least that used to be the case. Perhaps they've changed it. Perhaps now it simply doesn't change the GUID at all.

I don't have a "latest" version of the Corona to test that.

[Marcelair]

Hi, the 'GUID' or ID works strange, is it really new ? In this short clip I've been holding the binding button for 15 seconds, and didn't use the binding-button on the receiver, this is what happened;

--> http://www.youtube.com/watch?v=1bb9YSP2UCc The particular set was bought at HK on November 1 2009. There is no series-number on it.

So, it did bind, while it shoulden't. Did the ID change?, I think not, yet it should.

Another video, shows this; --> http://www.youtube.com/watch?v=4dZ7h_Kn ... r_embedded

Two radios are shown, two receivers, and different ID's. The one transmitter that corresponds with an specific receiver did work. But when the other transmitter was turned on, this changed.

[coronarc.nz]

Suggest you Skype "wxpots" (Billy Chou) at Corona and ask him the your questions. For those of you in the States (California etc) local time in China is about 6hours daylight time behind you (3 hrs in NZ).... just a day ahead...

[coronarc.nz]

ok, that does appear strange, theoretically it should have re-scanned all the frequencies and selected 3 new ones. I am not a technical expert so I could not tell you why, but Corona say to hold the module button for longer than 5 seconds when powering on to reselect. After that the receiver should need to be re-bound...
That is the idea, like I said, contact the guys at Corona - it is possible you have a faulty unit, you wouldn't be the first, and they are very good to deal with...
Roger