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whats so good about 2.4 ghz?!?!?!?

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Old 11-13-2010, 11:58 AM
  #76
HerrSavage
 
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Default RE: whats so good about 2.4 ghz?!?!?!?

Haven't read the whole thread, but I still run the 40mhz stock radio from my LST2 - with all four of my RC's.. Now with everybody else running 2.4, I really never have a problem.. Range, disturbance, etc.. - nothing to complain about.. Except maybe broken antenna tubes.. Only down-side really.. Plus I'm not going to spend the price of a whole new car for a new radio with four receivers to replace what I have now that works perfectly fine...
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Old 11-13-2010, 12:01 PM
  #77
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Default RE: whats so good about 2.4 ghz?!?!?!?

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ORIGINAL: ThunderbirdJunkie

It's so cute that downunderdog remembers all of ThunderbirdJunkie's posts from other threads nearly verbatim. Or has the time to kill to go back and look at them, whichever.
Downunderdog doesn't remember them. Downunderdog is quoting from page 2 of this thread, where Downunderdog had previously quoted most of ThunderbirdJunkie's thoughts on the subject. Forums are great in that when someone realizes that they're wrong and backpedals on their previous position without admitting to it, it is obvious and can be shown with direct quotes. Downunderdog finds that it is worth the effort to know what someone is saying, and what they've previously said on the subject, when discussing something with them, and it is not very time consuming to go to page 2 of this thread and read it.

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do his research, as in actual usage higher frequencies tend to suffer effects of distance more than lower frequencies. Downunderdog thinks it's due to the shorter wavelength in higher frequency transmissions - more attenuation by atmospheric factors or things that get between source and receiver. Just have a look at the FPV pilots - for a given transmitter power output and antenna gains, 900mhz will have better range than 2.4ghz or 5.8 ghz video links. Downunderdog's research has indicated that lower frequencies both penetrate obstacles better (that's why they use ULF for communication with submarines) and is attenuated less due to atmospheric factors (i.e. humidity, etc.). So, for ultimate range of RC transmitters and receivers, Downunderdog believes that the lower frequency spectrums (i.e. 27 Mhz AM, 72 Mhz) are THEORETICALLY better. However, as it's rare that Downunderdog would be operating a RC vehicle on the moon, ultimate theoretical range is neither here nor there... but I'm surprised that ThunderbirdJunkie and ThunderbirdJunkie's Mini-me did not bring it up.
As many of ThunderbirdJunkie's statements you can recall off the top of your head, it's shocking that you don't notice him saying just that (albeit in different words; IE it can go as far as vision will allow, so who cares)
Actually, Downunderdog was saying that it is surprising that that is, in fact, ThunderbirdJunkie's position - that they can both go as far as vision will allow, so who cares. Downunderdog has seen ThunderbirdJunkie throw out so many irrelevant supposed negatives that really are not negatives (see other quotes from ThunderbirdJunkie below) that Downunderdog is surprised ThunderbirdJunkie did not do the same in this instance.

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ThunderbirdJunkie has brought up a lot of irrelevant things in defense of 72/75 MHz, such as:

- RC jets using 2.4 gig and crashing (then ThunderbirdJunkie backs away from this statement and says that any frequency can be interfered with)
No, was just using this as an example of DSS/FHSS not being immune to a radio hit, as many others have claimed
Actually, ThunderbirdJunkie brought up a RC jet crash when someone said that 2.4G is less susceptible to interference than 75MHz. NO ONE has claimed that 2.4G is IMMUNE to interference. Downunderdog, and many others, believes that overall a given 2.4G system will be LESS susceptible to interference than a comparable (i.e. same price point) 75 MHz system. Does ThunderbirdJunkie disagree?

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- Reliability (ThunderbirdJunkie has yet to clarify how 2.4ghz is less reliable than FM)
First off, 2.4ghz DSS and FHSS are FM. So it's not possible for DSS/FHSS to be less reliable than FM.
Your normal PCM/otherwise one-frequency-bound radio, however, has been proven over the decades. DSS/FHSS has not yet been shown to be so as of yet, and with the lower and lower quality goods being pumped out because people want everything for next-to-free, it'll be shocking if we ever see the true potential in longevity.
Downunderdog will refer to 2.4 GHz spread spectrum technology as 2.4G or similar, and 72/75 MHz as 72 or 75 MHz to reduce the possibility that ThunderbirdJunkie will continue to use technicalities to obfuscate the merits (or demerits in the case of 75MHz) of each system. Downunderdog notes that 2.4G has been around for several years, and equipment made by reputable companies has proven to be very reliable. A two year sample size is sufficient for Downunderdog. Slower adapters may wish to wait until future improvements in technology someday make 2.4G the second best technology available before moving to 2.4G. Downunderdog wishes to emphasize that in Downunderdog's opinion there is nothing wrong with (other people, such as ThunderbirdJunkie) using "second best" equipment.

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- Ease of service (ThunderbirdJunkie has yet to clarify what this means)
Any Caribbean Jerk (or Queen, now we're sharing the same dream) that has a modicum of radio knowledge can diagnose and repair your average PCM FM or std AM RC radio in the event of a failure. Can you say that about DSS/FHSS?
Downunderdog raised his eyebrows when he read this argument. How often does this actually happen - $100 pieces of electronics, which are full of PCB's and tiny little components getting repaired? Downunderdog has, sadly, moved into the 21st century where typically repair of electronics components costs more than replacement (with better, due to improvements that are regularly being introduced) with new equipment. Easy fixes - like potentiometers or switches on a TX - can be repaired as easily on 2.4G as on 75MHz gear. Aside from that - the PCB, processor etc - on most sub $200 (replacement price) gear is not practical to repair.

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- Latency (first ThunderbirdJunkie brings up the fact that RC Jet flyers use 2.4 Gig, then ThunderbirdJunkie says that 2.4 Gig suffers from ''Latency'' issues. Curiously, ThunderbirdJunkie did not supply a link or any supporting information, as is usually the case.)
If you don't believe it, that's fine. Do your own research and prove ThunderbirdJunkie wrong if you really wish to debunk his every statement. It's something that can be felt in two similarly equipped cars.
It was Downunderdog's impression that ThunderbirdJunkie had never used "high end" 2.4G gear, but does use "high end" 75 MHz gear. Has ThunderbirdJunkie actually done a comparison between equivalent (price point) 2.4G and 75MHz gear? Downunderdog has NOT used 72/75 MHz gear, but feels that his 2.4 G reacts quickly enough for his needs (as do many operators of very expensive RC jet airplanes - as ThunderbirdJunkie mentioned earlier). Perhaps people who have used 2.4G and 72/75 MHz gear of similar quality/price point could chime in here? Kind of a survey to see if ThunderbirdJunkie is raising a valid point, or just more obfuscation.

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- ''bind-and-drive ability for a theif…'' (actually with all of the different spread spectrum 2.4 gig formats out there, Downunderdog believes that it would actually be easier to steal a 72 or 75 Mhz equipped vehicle - the RX's are interchangeable between brands, aren't they? Just change a crystal and off the theif goes. With 2.4 gig, most TX/RX combinations are brand specific.)
That was simply thrown in there as an illustration of the silliness in some of your posts. Again, you must be slacking on reading every single post ThunderbirdJunkie makes, since that was actually mentioned in this very thread.
Downunderdog read it, but was tired of typing "which ThunderbirdJunkie subsequently changed his position about" so Downunderdog let it go. Downunderdog guesses it is relevant, in that it is another irrelevant point that ThunderbirdJunkie brought up and then dropped when it was shown to be wrong - thus demonstrating credibility (or lack thereof) in the points that ThunderbirdJunkie raises. Downunderdog hesitates to say that it smacks of desperation, but hesitation only lasts for so long.

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ThunderbirdJunkie is lucky that ThunderbirdJunkie's Mini-me's research did not lead him to throw in the old ''signal attenuation affects range'' argument in there. Downunderdog actually believes that the fact that AM DOES travel a long way is one of it's major weaknesses. A transmitter on the same frequency that is VERY far away (maybe even on the moon, if one cares to pursue hyperbole like ThunderbirdJunkie has been known to) can cause interference with an AM user right here in a park on earth. The real truth is that the all of the available frequency spectrums that have been allocated for RC model use have enough theoretical range to go beyond what any of us would normally need (except maybe FPV pilots who fly beyond visual range). What sets 2.4 gig apart is the extra bandwidth that is available at the higher frequency. That bandwidth can (and is) used to differentiate the signal from the noise. The TX can send a lot more data to the RX, and the RX can process the data to determine what is being transmitted by what it is bound to and what is noise or interference from other, unwanted, sources. So, while 27 Mhz or 75 Mhz may have more theoretical range, 2.4 gig actually has more USEFUL range because it filter out the interference, and the model does NOT do what 5 (or even just 2) different things that are all within range are telling it to do. It just does what the one transmitter that it is bound to tells it to do.
Cool. It's pretty neat that you learned how to use lots of big words to make yourself sound smart, yet never learned not to end a sentence with a preposition.
Downunderdog notes that the word "do" is not a preposition. It is a "pro-verb" or auxiliary verb. Downunderdog also notes that, although using big words might make someone sound smart to someone who is not smart, it is the thoughts that are being conveyed by those words that someone who is smart uses to form their opinion of the person who is using the words.
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Old 11-14-2010, 04:02 AM
  #78
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Default RE: whats so good about 2.4 ghz?!?!?!?



im out of popcorn[] keep debating please why i get some more

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Old 11-15-2010, 08:59 AM
  #79
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Default RE: whats so good about 2.4 ghz?!?!?!?

Quote:
ORIGINAL: ThunderbirdJunkie

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- Latency (first ThunderbirdJunkie brings up the fact that RC Jet flyers use 2.4 Gig, then ThunderbirdJunkie says that 2.4 Gig suffers from ''Latency'' issues. Curiously, ThunderbirdJunkie did not supply a link or any supporting information, as is usually the case.)
If you don't believe it, that's fine. Do your own research and prove ThunderbirdJunkie wrong if you really wish to debunk his every statement. It's something that can be felt in two similarly equipped cars.
Downunderdog does not really wish to dubunk every statement of ThunderbirdJunkie... only the misleading or incorrect ones.

From Spektrum's website, some information [link=http://www.spektrumrc.com/DSM/Technology/DSM2.aspx]about Latency.[/link]

"With DSM2, the total latency of your radio system has been greatly reduced, while the bit-rate has been increased. When combined, these improvements provide hobbyists with a faster and more locked-in feeling when compared to traditional 27MHz, 72MHz, or 75MHz radio systems."

Does ThunderbirdJunkie have a link to anything that discusses latency comparisons between 72/75 MHz and 2.4 GHz systems which indicates 2.4G is worse? Or does ThunderbirdJunkie prefer to speak in generalities like "Latency. It's something that can be felt in similarly equipped cars." ThunderbirdJunkie never even stated whether the latency of 2.4 G was greater than or less than 75 MHz, or how the effect made the cars feel. Perhaps ThunderbirdJunkie believes that higher latency of 75 MHz makes the feel of the cars better? Could ThunderbirdJunkie please clarify?
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