Spektrum Technology

Tue Oct 25 04:46:07 AKDT 2005

 There's some very good reading on this link, even talks about this system even uses 2 channels not one for transmission, if I read it right. This is the manufacture of the radio system.
http://www.spektrumrc.com/
 Steve Maxwell

----- Original Message ----- 
From: Bob Richards 
To: discussion at nsrca.org
Sent: 10/25/2005 10:04:42 AM 
Subject: Re: Spektrum Technology

Troy,

Sounds great, but I have to wonder about 2.4 ghz. That is an ISM frequency, and has relaxed emissions limits for some products as a result (the only way that a microwave oven will pass the regulations). It sounds fine as long as we are the only users of that band, but in fact we are only one of a large group of users of the 2.4ghz band. Wifi, Hams and amateur television, cordless phones, home networks, etc.

What you describe does not sound like true spread spectrum, ie: it picks a clear frequency and then locks onto that freq. I would think a true spread spectrum system would channel hop during operation, so that interference on any single frequency would not cause any problem other than a few dropped frames. The link you referenced seems to indicate that the system DOES do spread spectrum.

I guess most of the other users of the 2.4ghz band (besides us) would not be close to a flying field environment, but you never know. Most of them are also limited in power and distance, which is also good for us.

I remember when FM first came out, and everyone said that was going to be a cure-all for interference. Some even said that AM and FM could fly on the same channel at the same time (reported in one of the magazines!!). Lots of speculation and misinformation, at least initially.

2.4ghz is probably much better than what we have now. However, we have always been secondary users of any frequency that has been allocated for our use, and that does not appear to have changed and I suspect never will change. I'm not trying to rain on anybodys parade, I just want to be cautiously optimistic.

Bob R.

"Troy A. Newman" <troy_newman at msn.com> wrote:
Ok guys it is finally here. This weekend at the Houston(Tomball) SPARKS 
contest I was asked a few questions about this new and exciting product. We 
as pattern flyers are going to benefit from this.
I have had the opportunity to be flying one of these systems for the last 
few months.

http://www.horizonhobby.com/Shop/ByCategory/Product/Default.aspx?ProdID=SPM2460

I have tested this system both my local flying field here in PHX (Sun 
Valley) as well as flying foamies and such in my yard and local parks.

The system has been 10000% glitch free. I can't find anything in the system 
that responds differently than my 10X. Response time is faster than PCM, the 
resolution is excellent, better than anything out there currently for any of 
the radios systems. There is nothing about this system that is below 
outstanding. Basically the system solves two very important problems we 
have in modeling today:

#1 No frequency control issues. There is no frequency pin needed and you 
would not even know which one to choose because the system picks a frequency 
that is open when you turn it on. Don't get shot down again. This system can 
operate with like 80 different TX's all at the same time and no interference 
issues. This will make the frequency pin obsolete! The system boots up about 
3-5secs and picks a frequency not being used. It then tells the RX what 
channel to listen too and you are done. You don't even know what channel you 
are flying on and it doesn't matter either. Another TX turns and scans the 
air and picks another frequency and uses it. Its totally user 
friendly...Basically you just turn it on and its working. It has a Failsafe 
safety feature than can be programmed when you "Bind" the RX to the TX. This 
Failsafe works just like PCM failsafe. The Binding process is how you tell 
the RX "who's your daddy" This process takes about 20secs and from then on 
the RX will only listen to your TX. If a buddy wants to fly it with his 
TX....just 20 secs later after you tell "who's the daddy" its now listening 
only to that TX. We have all been at an event with the foamy flying at night 
and the call for frequency is heard from the other end of the parking lot or 
pits. This is never a concern again with the Spektrum System from JR and 
Horizon Hobby.

#2 Model generated interference is not an issue. I have tried using this 
system on regular brushed electric powered models sometimes in this 
environment you can get a glitch or the likes running PPM (FM) systems. This 
new 2.4Ghz system eliminates this problem. Its like PCM in that it rejects 
bad stuff and keeps the good stuff. From my understanding model generated RF 
problems like brushed motors, metal to metal contact (drives FM stuff nuts), 
ignition systems, and the likes....this new 2.4ghz stuff is way above those 
model generated interference frequencies.

I love the system. I know Horizon has spent a huge amount of time testing 
and evaluating this system. It is a revolution in RC.

We have been basically flying on the same types of signals since I have been 
involved in RC in 1981. The one big weakness with our 72mhz system in my 
mind is no matter how good your equipment is, not matter how much you have 
invested in a model, no matter what TX you have 14MZ, 10X or the likes a 
shoot down can happen with a attack4 AM radio. The result of a mistake in 
the pits or parking lot can cost you your model. A simple mistake by an 
experienced or new modeler can cost any of us our models with previous 
systems.

We have all heard of the stories about getting shot down.

Well this system is the first step to eliminate this problem! I can say its 
been eliminated on this 6 channel radio system. Next step is for big radios.
The RX's are cheap about $60. They are light about 7-8g (6channel RX)and the 
RX has 2 different antennae. They are about 3-4" long...so no more stringing 
the extra out the tail of the model. There are lots of other advantages in 
this new technology. All this and the same high quality stuff that JR 
produces with the 72mhz stuff.

This radio system is priced and setup for the park flyers, but its only a 
matter of time and we all will be benefiting from this stuff. Besides as 
said above making this system available for a good price to the everyday 
modeler where it is needed is the first step to really change the way we fly 
our models.

If you guys have any questions I would be happy to answer them. My 
experience with the system has been absolutely flawless and I know others 
have had the same. This stuff is ready for prime time and its going change 
things in a huge way.

Troy Newman
Team JR
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