Michel

Hi

I,m " OLD " , ................... does that explane it

Michel

AJsToyz

Can't be to old, still having fun and playing with toys!!

Wayne Miller

Reference post #'s 3716 and 3717

Hi,

Thanks Michel. I've looked at all three video's and the last one states there are 59 2.4 channels and apparently the Spectra module uses the cleanest 20. I'm making the assumption that SmartScan will pick the 20 cleanest channels to be use and keep those until another SmartScan is made. Only one of the channels will be used at a time, if it has a problem, then the system will jump to next clean channel out of the 20 automatically.

I'm trying to get a handle on how the Spectra system works just to build confidence. I hope the above is correct - can anyone confirm? If the above is not correct, can anyone explain what actually happens?

Thanks for your help.

Fly4Fun,

Wayne

A.T.

Quote:

ORIGINAL: Wayne Miller Reference post #'s 3716 and 3717 Hi, Thanks Michel. I've looked at all three video's and the last one states there are 59 2.4 channels and apparently the Spectra module uses the cleanest 20. I'm making the assumption that SmartScan will pick the 20 cleanest channels to be use and keep those until another SmartScan is made. Only one of the channels will be used at a time, if it has a problem, then the system will jump to next clean channel out of the 20 automatically. I'm trying to get a handle on how the Spectra system works just to build confidence. I hope the above is correct - can anyone confirm? If the above is not correct, can anyone explain what actually happens?
Thanks for your help. Fly4Fun, Wayne

Quote:

ORIGINAL: A.T.

Quote:

ORIGINAL: LQUAN Mike, May I ask how does the AFHSS in Aurora9 work? Does it constantly hopping accross the bandwidth at equal fixed interval like FASST? What makes this an Adaptive Frequency Hopping Spread Spectrum? How does it Adapt when encounter inteference?
Does the RX tells the TX to hop when RX looses frames or does the TX tells the RX to hop when it found a stronger path in the bandwidth?
AFHSSExplained
"12Dec09 = Hitec AFHSS hops continuously, like Futaba, but between 20 channels .
There are two ways it can work.
Normal mode, (default) uses the same 20 channels as when it was bound. This has almost instantaneous linking time, and you can operate redundant RX's if needed.
Scan mode scans the band (79 channels) every time it turns on to pick the cleanest 20 channels to use. The link time is about 3-5 seconds, but you must cycle power if you lose power to either TX or RX (not brownout condition,) and you cannot use two RX's at the same time for redundancy."
Extract from Auroramanual:
"Normal Mode
- In this mode the receiver/transmitter uses the frequencies which selected at the time it was initially set-up.
- After the initial set-up, the everyday start-up is quicker in the Normal Mode. In 90% of cases the Normal Mode is preferred by users.
- In the Normal mode, if the transmitter or receiver loses power, then power is restored, the system will re-link and function normally.
- The factory default setup is Normal Mode.
Scan Mode
- In ScanMode the receiver/transmitter will scan all available channels every time you turn it on.
It will then choose the cleanest frequencies to use. ScanMode is preferable to use when flying in a crowded 2.4GHz environment.
- While in ScanMode if the transmitter loses power it will not rebind to the receiver, if the receiver loses power it will take longer to re-bind than when in Normal Mode.
- In all cases the ScanMode binding function will take longer than in Normal Mode when you boot-up the system."
Alan T.

Quote:

ORIGINAL: A.T.AFHSS - How To Select Optimum Channels - For Your Field ***
20Apr11 added:
"New "smart scan" is basically an easier way of picking a new set of channels per your environment other than going into scan mode and then back to normal mode which is what is recommended to use. Scan mode was nice that it picked a new set of channels each time, but really unnecessary and some of the downfalls with having to cycle power on the both the TX and RX made it inconvenient. First of all note that the Hitec team has never done the scan mode to normal mode trick as we use the same channels picked by normal mode and have flown at all the major events with zero issues. The only time I would suggest you use the scan function is if you need to avoid another device or if somehow you are having problems at a specific field.
Linking telemetry and non-telemetry Rx's... the technology requires a different binding method. When binding the Optima (telemetry) RX's you would utilize the same exact procedure that you are familiar with, but with the new Minima RX's, you must push the link button again to get the blue light flashing

. V3.01 firmware removes Scan mode for operation.
Instead, it allows you to re-scan to select a fresh set of channels
(re-binding your other RX's will be needed after this)
and then operates in Normal mode with the new channels.
Spectra Module V1.01, V2.00 & V3.01 Updates & Manual. Screenshots & additional information.

AFHSS in operation - Hitec Spectra 2.4 GHz and Optima Transceiver (RX)- Video #1 = Normal Mode, Video #2 = Scan Mode.
AFHSS in operation - Hitec Spectra 2.4 GHz and Optima Transceiver (RX) -Video #3 (Answers queries received ex Videos 1 & 2., see also post #2933 page 296}

AFHSS - Channel selection - full thread may also assist.

ex Hitec USA Support Forum Sticky:
Aurora 9, Spectra Modules & Optima Transceivers
- FAQ & Undocumented Features
- Mixes, Setups,Tips. {Individual Links often updated}

Alan T.
Alan's Hobby, Model & RC FAQ Web Links

lunarhemal

Dear Michel,

Thanks for your help on uploading images. I did it !! cool !! i notice that this can be done only when you post reply and not at the bottom of the page where u can write in general. There is a icon for images, but it asks for a URL address and not allow to browse. - strange !!!

thanks anyways, !!

Hemal

Wayne Miller

Hi,

Thanks for your help regarding the scanning, I understand the operation now.

Fly4Fun,

Wayne

Wayne Miller

Hi,

I've just posted a document in PDF format describing what I have found out about the Aurora 9 Software and Firmware updates, understanding SmartScan and also linking procedures. I tried to keep the explainations simple.

If you are interested in taking a look, here is the link:
http://www.rcuniverse.com/forum/m_10...m.htm#10631132

I hope you find it useful.

Fly4Fun,

Wayne

Chancho

Thanks for the work Wayne,

I've printed a few of your other documents out and this is a nice add on. It's refreshing to see some original posts andnot the typical blanket reply.

"You Canucks are A - O.K. in my book.":-)

Phil

Michel

Hi Wayne

Extremely useful ,........ THANKS

Michel

vasek

My Feedback: (4)

+1

Wayne Miller

Hi,

I just fixed a typo and uploaded the new document to the post for downloading.

If anyone sees anything else that should be changed, please let me know. Thanks for your help.

Fly4Fun,

Wayne

gsoav8r

My Feedback: (6)

Hi Wayne, Overall I like what youve put together, simple and streamlined for a quick reference.
However, I believe your interpretation of how frequency hopping works is incorrect. Its my understanding that the 20 channels that the system selects or allocates are used repeatedly at a very fast rate. So fast in fact that the when looking at a spectrum analyzer the channels seem to be in use continuously. In other words I dont think spread spectrum systems ever sit on just one channel waiting for interference or a problem. The idea with SS systems is that if the Rx cant use signal from one channel or its blocked out completely, it doesnt normally matter because the bad/lost signal is so brief (fraction of a second) and because the system has already hopped to a, hopefully, usable channel. Im pretty sure that over the duration of a flight the system channel hops 100's of times, possibly thousands.

Another thing to be aware of too is that during binding your telling the Rx to only listen to your Tx. The Rx will only decode signals that have your Tx ID code (or whatever the actual name for the code is). Because of the code, it is possible for a brief moment that two or more Tx's could be transmitting on the same 2.4 channel and not have interference issues because the Rx's are only listening for and decoding signal that have your Tx's unique ID code. In heavy 2.4 environments, like a mega-meet, its possible for a channel [or multiple channels] to be so swamped with radiation that the Rx cant work. [This is why its better to have a SS system that can channel hop across many 2.4 channels.]

Let me add too that Im sure something Ive written here can be faulted or may need slight correction. My only motive here is to give some idea that SS is very complex and not as simple as it seems on the surface.
Heres a good read if interested. Plus if you google spread spectrum you'll find tons more info.
http://www.rcmodelreviews.com/spreadspectrum01.shtml

Cheers,
James

[ Edits ]

Wayne Miller

Hi James,

I must admit I don't have an indepth understanding on how the frequency hopping works, I'm hoping that I can find a simple and clear description explaining the Aurora's method. If I do, I'll incorporate it into the document.

Thanks for your insight and the link to the reference site and for taking the time to look at the document, your comments are very helpful.

Perhaps someone here knows of a reference site that may explain the Aurora system specifically, if so, please let us know.

Thanks for your help.

Fly4Fun,

Wayne

Zor

Of course the designers of the systems do know what they are doing and how they do it.

Their competitors likely also know but this knowledge is considered "proprietary".

Different system manufacturers (designers) respect each other secrets (logically).

I spent quite a bit of my time to try to find "What exactly is going on in this Spread Spectrum technology".
I have read many theories put out (written) by pople who apparently try their own logic "to guess" what is happeniing.

We still do not know for sure, perhaps some day ___???

Zor

gsoav8r

My Feedback: (6)

Agreed, I dont know that anyone knows for sure exactly how a specific Mfg system is working but I think we have a lot of good and logical clues.

We know that SS broadcast over multiple channels fast enough that the analyzers see them as constant sources of radiation. RCMR reviews give us that.
How many channels are actually being used by the Rx in a second or over the course of a flight, I probably shouldnt have guessed but to me it does suggest hopping occurs frequently.

Plus Im fairly confident that the Bind Id codes are doing their jobs well. What, 300-400 Tx's have been in operation, all at once, at mega-meets without many issues (there have been some issues thou). 300 planes / 59 channels? = about 5 planes / channel. I dont know how many Tx's operating on the same channel it takes to completely saturate a channel but I think the probability is high enough that it dictates some rate of hopping.

ZeekWorld

Here is a link to a Facebook Page with good Aurora 9 info. Nothing you can't find around here but sometimes is good to have an alternative source you can quick preview [link=http://www.facebook.com/pages/Hitec-Aurora-9/158555190880502?sk=wall]Facebook Aurora 9[/link]

Michel

Hi

I don,t think we can bring facebook to the field , ( and I don,t want to ) , and most , if not all owners know about the sites that support the A-9 . Wayne,s info , you can put with youre transmitter case ,and use it at the field , " where we need it " .
Michel

Ken Cz

Wayne-
Thanks again for the great information on the A9 and for Tim Horton- one of Hockeys' Greats! We love the Coffee Shops now here in MI and were frequent customers before on our many trips to Ontario!
I've saved your document and will send it out to friends w/A9.

Best,
Ken Cz-
Oxford Mi

Wayne Miller

Hi,

I figured there must be a better way to switch antennae when using 72Mhz and 2.4Ghz with the Aurora 9 or Optic 6, so I put some thought into it and came up with a simpler way.

The following post shows what I did - it is easy to make and very effective.

http://www.rcuniverse.com/forum/m_10...m.htm#10632786

I hope those who fly both 72Mhz and 2.4Ghz find it useful.

Fly4Fun,

Wayne

Zor

Hello Wayne,

A bit of understanding help if you do not mind.
The local LHS does not have the Hitec radios so I cannot go there to clarify my mind.

I see your ingenuous method of mounting both antennas 72 Mhz and 2.4 Ghz permanently on your Hitec transmitter.

So I understand that the RF modules both have a connector on their outsides where the antennas are plugged in.

When switching bands we would have to disconnect the antenna and remove the module for that band theninstall the other module and plugin its proper antenna.

Is this all correct ?

Thanks for your help in understanding. I have been considering buying one of these Hitec A9 with both modules.

Zor
.

Wayne Miller

Hi Zor,

The 2.4 Ghz module comes with an antenna attached by a wire. The 72Mhz module comes with a separate module and a separate metal antenna when you buy it.

To use the 72Mhz module you normally unscrew the 2.4Ghz antenna out of the Aurora 9 case and screw in the metal 72Mhz antenna, then put in the 72Mhz module. The 72Mhz module connects to the metal antenna internally through the pins on the module, you will not see any wires.

What I did was to make a mount so I could leave the metal antenna in place so I just had to replace modules and put on the 2.4Ghz antenna when needed. I did not want to keep unscrewing and installing new antennae.

The Aurora 9 knows which module you are usiing and will operate accordingly.

When you put in the 72Mhz module you must initially select the type of modulation (PPM positive or negative shift) and the 72Mhz channel you want to use (selected from the screen) before the Aurora 9 will transmit on 72Mhz. After the initially selection, you will just have to plug in the 72Mhz module to work. Any channel or modulation changes (pos or neg, for Futaba, JR, Airtronics, Hitec etc) are selected on the screen.

Hopefully this makes sense, if not I can send pictures of each installation.

Fly4Fun,

Wayne

BuschBarber

My Feedback: (2)

The Coax for the 2.4 antenna connects to the 2.4 Module. The metal antenna screws into the Transmitter body.

Zor

Thanks a lot Wayne
Inserts in red by Zor

Again many thanks for your valuable time.

Zor

Wayne Miller

Hi,

My Aurora 9 transmitter beeps every time it switches between transmitter battery voltage and percent display, it does this about every minute. I've searched but can not seem find any reference on how to turn this beeping off.

Does anyone know if this beep can be turned off, or can I program the display to have either battery voltage, or percent, so it won't keep switching and therefore (hopefully) won't beep?

Thanks for your help.

Fly4Fun,

Wayne

A.T.

Aurora 9 - After Market Accessories: Caution re Opti-kill, Duralite, Powerbox, Switches, Leads etc.

Update
"FYI: The RX firmware update V3.01 should be up in the next couple of days. There has been speculation (as there always is) as to the validity of this update and the causes of some of the problems we have seen; All I can say it this is a GOOD THING as it improves the noise rejection capability of the RX as well as includes a re-boot feature if is it affected so at least it has a chance to recover. If other factors are involved then they will be addressed as well as needed.- Mike. "

. It would be all Optima's in which only the 7/9 can be updated by the user.
It is unknown if we will be able the O6's. Future RX's will have the updated firmware from the factory.- Mike.

. No need to remove them (Optima),
just connect to the data connection and your're good to go. While not a necessity, it's not a bad idea to rebind after an update and perform a range check just to be on the safe side.- Mike

Alan T.
Alan's Hobby, Model & RC FAQ Web Links