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Old Oct 31, 2012, 11:50 PM
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Australia, VIC, Melbourne
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Originally Posted by Elios000 View Post
wi-fi is moving to it
Thats more for speed than connectivity. The higher the frequency the more data you can cram in.

The higher freq also bounces off walls and stuff more so will probably work just as well or better indoors. That and a LOT of low power indoor devices compete on 2.4G. RC gear can shout all over the top of them (200mW vs 5-10mW) and uses spread spectrum that wifi cannot (unless you want it slower than dialup).
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Old Nov 01, 2012, 12:44 AM
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United States, ID, Burley
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i had a friend that got very paranoid and thought every plane flying over was watching him ? It twas the doobies or hooka i think they now call it
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Old Nov 01, 2012, 09:23 AM
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Illinois
Joined Sep 2001
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Originally Posted by Warningshot View Post
AMA had nothing to do with getting 2.4.. All they did was bless it. The radio makers did it on their own. Thank them not AMA.
I don't think the plural "makers" is appropriate. It was one company that did all the legwork with the AMA to show them the light. Everybody else just tagged along on our efforts.

Andy
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Old Nov 01, 2012, 11:48 AM
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United States, AZ, Mesa
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Originally Posted by Elios000 View Post
the spread part is purely about using more then one channel ether at the same time or hoping or both
OMG, no it's not... is anybody paying attention or what? PLEASE... read the information that is freely available! Frequency hopping is NOT the only, or even the best, way to spread a signal. Spread spectrum is a whole lot more complicated than using multiple channels - that isn't even spread spectrum, that's transmitter diversity or something like that.

Please read these articles. I'm getting really tired of people thinking that spread spectrum means frequency hopping... Spektrum DSM2 is VERY misunderstood and unfair things are constantly said about it by people who don't understand DSS, so please, you owe it to yourself to understand so you can ignore/debunk those misleading statements.

http://en.wikipedia.org/wiki/Frequency_modulation - DSS makes zero sense if you don't understand FM basics
http://en.wikipedia.org/wiki/Direct-...pread_spectrum - this explains why, because of the PN ratio, you need higher frequency carrier waves to transmit a lot of data with DSS. Basically you need the ability to transmit a signal that is much faster than your actual data rate.

Quote:
Originally Posted by desertstalker View Post
Thats more for speed than connectivity. The higher the frequency the more data you can cram in.
Right that's what I was getting at before. With Wi-Fi, extreme range is actually a security problem, so reducing the range is not an issue for most uses, but getting lots of data really fast is important to consumers because they want to watch Netflix.
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Old Nov 01, 2012, 04:13 PM
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United States, FL, Miami
Joined Aug 2009
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Originally Posted by Elios000 View Post
wi-fi has very tight power limits at lest on phones and laptops
and i dont think what why up the model is means much at lest with Spektrums sat style setup
Wifi power has been going up recently.. 1000mw boosters can be bought at local stores, 600mw routers too.

Heck, the factory router/modem AT&T gave me for internet was set on 400mw by default... Not to mention Wirless N intentionally takes up multiple WiFi channels for bandwidth..

FWIW, I've never been shot down on 72mhz, I cant say the same for 2.4ghz.
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Old Nov 01, 2012, 04:37 PM
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Originally Posted by RC Man View Post

The robustness of 2.4 is very dependent on the manufacture of your radio. Spektrum has the worst reputation for having RF link problem is high traffic areas. After I switch to Futaba FASST I have never had any more problems.


.
Please explain in the best detail in which you are capable of mustering.
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Old Nov 01, 2012, 04:45 PM
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Originally Posted by JetPlaneFlyer View Post
Yeah, the problem comes when there are so many transmitters operating that the Tx cant find a free frequency and so ends up being forced to take one that's already occupied.
I thought that wasn't supposed to happen with DSM2. The, ahem, "big wigs in the know" stated a TX turned on in a situation like that simply won't transmit until frequencies become available. So, they say...
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Old Nov 01, 2012, 04:53 PM
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From what I have seen- this is true .
The SPEKTRUM looks for a channel which is "clean enough".
some others just hook up n hope for the best . BUT according to Queensbury rules - you must not interfere with others use of the allocated spectrum- so you can't HOG a particular channel.
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Old Nov 01, 2012, 05:14 PM
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Originally Posted by richard hanson View Post
so you can't HOG a particular channel.
DSS doesn't hog the channel it's using, it simply increases the noise level on that channel. Systems like FASST and DSMX increase the noise level of the whole band.
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Old Nov 01, 2012, 05:24 PM
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Originally Posted by jasmine2501 View Post
DSS doesn't hog the channel it's using, it simply increases the noise level on that channel. Systems like FASST and DSMX increase the noise level of the whole band.
I meant that NO ONE can hog the slot - and the DSM2 does not -
it does use it but so may others .
This fact seems to confuse the terminally bewildered (not you) - likely because they still think the channels used are only available to one user at a time . just like the old 72.xxx freq.
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Old Nov 01, 2012, 05:33 PM
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Originally Posted by gwinhh View Post
Hate to sound like an Old Phart, but in the '80's, we had 6 frequencies (there were a couple reserved for licensed Ham radio guys), lots of interferance, and only 2 or 3 folks (depending on frequency) could fly at one time (cross-channel interferance).
Oh, please... I started flying in the early '80s and there were far more than six frequencies (i.e. channels) on 72MHz alone. Are you confusing "frequency" with "BAND"?
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Old Nov 01, 2012, 05:43 PM
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Originally Posted by crvnation View Post
Oh, please... I started flying in the early '80s and there were far more than six frequencies (i.e. channels) on 72MHz alone. Are you confusing "frequency" with "BAND"?
In the early 80's there was only a few channels available in 72/75 Mhz(some for air some for surface)the 6 meter band and the 27 Mhz for air and surface. The new 72 Mhz/75 Mhz narrow band came latter on!
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Old Nov 01, 2012, 05:47 PM
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Originally Posted by coriolan View Post
In the early 80's there was only a few channels available in 72/75 Mhz(some for air some for surface)the 6 meter band and the 27 Mhz for air and surface. The new 72 Mhz/75 Mhz narrow band came latter on!
I started flying in '83 and had one of the old gold metal cased Futaba AM radios as my first TX. It wasn't narrow band because I remember having to spend my hard earned allowance to have it converted so it was "legal". There was an entire line of frequency/channel card slots the three fields I flew at back then...a lot more than 6, that's for sure... Perhaps what you say was true for the extremely early '80s, but not from what I remember when I started flying.
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Old Nov 01, 2012, 05:48 PM
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Originally Posted by richard hanson View Post
This fact seems to confuse the terminally bewildered (not you) - likely because they still think the channels used are only available to one user at a time . just like the old 72.xxx freq.
At my old company, we had the problem where people in the accounting department would start telling the computer programmers how to code stuff...

The policy that finally worked was "If you don't understand what the other person is saying, you have two choices: either learn to do their job, or trust their expertise and shut up."

Problem in the RC world is everybody is an expert on everything. We are highly intelligent people for sure, probably most of us are above average. However, if you're not a radio engineer, it's pretty damn ballsy to be commenting on the reliability of something that was designed by actual radio engineers. I think from now on, my response to that kind of assertion is just going to be "please post the data that the Spektrum engineers didn't know about" because those assertions are really saying "I'm smarter than the Spektrum engineers"

Seriously - if you're going to say Spektrum did it wrong, you need to be prepared to explain yourself, in terms that are scientifically accurate.
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Old Nov 01, 2012, 05:49 PM
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Quote:
Originally Posted by coriolan View Post
In the early 80's there was only a few channels available in 72/75 Mhz(some for air some for surface)the 6 meter band and the 27 Mhz for air and surface. The new 72 Mhz/75 Mhz narrow band came latter on!
Yep. Mid to late 1980s for the 20mHz apart narrow band 72 stuff. All 72 had to be narrow band by 1991.
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