2.4Ghz

[Steve Smith]

Has anybody used this type of Radio yet.  What stops interference from a wifi hot spot or any other wifi device in the area?

[Steve Smith]

Found this on a site:

"When you fire up your DX6, it searches for, selects and locks onto clear channels. (There are 80 channels in the 2.4GHz band.) And because international regulation of the band is very strict, your radio will neither sustain interference from nor cause interference to  any other 2.4GHz device worldwide**. And that applies, of course, to its simultaneous operation near other 2.4GHz RC radios as well.
 
Spektrum‘s 2.4GHz surface radio equipment has already taken the RC car racing world by storm. Its working great and the podiums already contain racers using DSM technology. Planes and helis, however, present a constantly changing “target” for reliable RF link. So Spektrum solved this transmitter-to-receiver orientation challenge with an innovative 2–in– receiver configuration that delivers an extremely robust RF link and extraordinarily secure flying. It‘s a solution so unique a patent‘s been applied for."

[Andrew L]

Hello!

I use a DX7 and have never had any issue with RF interference. I have used it in my garden and never had my or my neighbours access points screw my signal up.

[Steve Smith]

What are the restrictions on the UK with regards the number of guys that can fly at the same time?

[Andrew L]

The BMFA don’t enforce/suggest a limit. Club rules governing the number of models airborne at any one time should still reflect the needs and circumstances of the particular flying site. I have seen 8 or so Trex 450’s drag racing without issue other than the usual dumb thumb stuff.

[spacey]

Hey guys!

The 2.4 stuff is well proven to work IMHO, at the JR indoor the first time out they had 50 odd in the air at the same time and as Andrew said apart from the indoor arena getting awfully crowded and the odd dumb thumb happening the system worked flawlessly. At the pylon racing world champs guess what the majority was using...spektrum of course. At the F3C world champs the top three Curtis Youngblood, Scott Gray and Hirioki Itou was all using spektrum amongst a few others. Scott and Curtis had the new JR 9X 2.4gig production models and Itou was using a prototype 12X 2.4. I don't know if I'm allowed to say this but ok I don't think it's really a secret or anything, we've had one of the very very first plug in 2.4gig demo models we've been testing at our club for ages now flying it in everything possible from .90 size helis to a 33% H9 Edge and it's been working absolutely flawlessly. Since we've had many members of the club switching to the 6&7 channel radios, mostly the DX7 (Awesome little tranny) and no problems whatsoever reported.

I've personally seen a really glitchy to unflyable overpowered pocket rocket of a Microjet have all its issues resolved by going spektrum. Personally I feel this may be a bit of a bandaid applied and not a problem resolved but ok I've got glitching problems in my little pylon racer as well and have tried everything humanly possible except switching to spectrum to get it flyable...at 200km/h+ on a 1/2m wingspan model a glitch is not welcome.

SAMAA's rules about only 5 at a time going or something is IMHO like our lovely traffic department putting 40km/h warning signs up making us drive 40 on a 120km/h highway without there being roadworks at all. I don't mind SAMAA taking the safe route untill further notice to do a little testing or anything but I do feel they've yelled wulf on this one only causing unneeded concern and questions.

2.4 is not a flawless system in any way but it's for me a helluva much better than 35mhz...now 35, there's a flawed band if you ask me. 2.4 Also has a few issues however with carbon just like 35mhz apparently but this is also easily overcome. Other than that? I haven't seen anything.

[Andrew L]

What are the isssues with carbon and 2.4?

[spacey]

Hi Andrew,

Carbon also apparently masks and bounces the signal a little so you have to get the antenna out of a carbon fuselage properly, just like with 35mhz. The glider and pylon guys picked up on this however and already there are widespread articles written on how to solve the problem by extending the antenna and and. Apparently it's much easier than the 35mhz fixes because you don't have to do any soldering but yes still care needs to be taken on the length of the antenna and of course all the angles should be covered. I saw a neat article in the high performance forums on RCGroups, if I get around to browsing again there today I'll see if I can find it so I can drop the link in here. The guys on the MGASA group here locally also confirmed they needed to do a a little extra to get proper range on their F3B and F3J gliders with the carbon fuses, you can't just leave the antenna's inside the fus.

I'll get back to this one.
Groete,
Rudolf

[spacey]

Here we go, some excellent info in this thread and in the links posted to solutions.

http://www.rcgroups.com/forums/showthread.php?t=797157

[Andrew L]

That issue would apply to most materials to some degree, water would have the greatest effect as it absorbs most of the energy (so no flying under the waves   ).

That is why the RX has at least two antenna, that way the RX would likely have one decent line of sight view of the TX which helps overcome multipath, reflection type issues.

I do believe that the reason that the AR6X00 RX is limited to park flyer status, not not the AR7000. I am guessing the power output is the same and therefore the range would be similar but the coverage created but the "satellite" antenna improves the coverage greatly, especially seeing that Spektrum suggest that the antennas be place perpendicular to each as the signal propagates in a doughnut looking fashion from the antenna (when looking at the tip of the antenna).

Anyhow most importantly it solved the horrendous glitching/lockout issues that my Futaba PCM radio was having in the carbon framed EMF storm masquerading as a Trex 450.