RE: Spektrum DX-7
 

k3 valley flyer and KB9STD,
I wasn't going to say this but since you two bring this up, I looked at the JR 7202 and the Spektrum DX-7 and was wondering when someone would look at the two and swap the RF section and test it. Seems like an easy reverse engineering project from someone with the right equipment. How difficult was it to do the conversion?

RE: Spektrum DX-7
 

Gentlemen,

There is a suttlety you may be missing. The DX6 is a PPM signal to the RF deck. However, if you read the DX7 announcement it says the receiver also listens to the xmitter for the correct model to have been selected on the transmitter. The only way this can happen is this data is also sent at binding time. This is not a standard componet of a PPM signal. Therefore, I sumerize that the DX7 transmitter has some different firmware and that would make it not practicable to put its RF deck in another transmitter.

Just my $.02

RE: Spektrum DX-7
 

You have a good point. However, my guess is most 9303 users would be willing to lose "model match" if they had a 2.4 module to fit their 9303 tx so they could buy one module and a 2.4 receiver and still swap back the 72 module and continue to get value from their 72 band receivers. The lack of modules for the existing equipment says Horizon wants the market to not only purchase a whole new complete system but also replace all their old 72 receivers with new 2.4 ones! A big investment if you have very many old receivers! Besides I don't believe the "improvements" 2.4 offers are all that important. Mike McConnville only wants to talk about how "locked in" 2.4 is, my existing equipment is far beyond my skills already. As far as interference have not had an issue since pre 1991. Most radio glitches are really glitches of the pilots thumbs. And as far as frequency control have not had or seen a shoot down in many years. Would a 2.4 option be nice to have for a visit to a "foreign" field for a fun fly? Yes, but the benefits for general use do not justify replacing the receivers in the whole fleet. At least not yet in my current environment, I am sure others will feel and act differently and that is what Horizon is counting on.

RE: Spektrum DX-7
 

If the radio ignores this data return, it should not prevent the RF section from being used. You just will not have that feature that the radio can utilize. RIGHT??????

RE: Spektrum DX-7
 

Wow guys. This is interesting. A few quick comments then I gotta run again and head to AZ for the USRA Championship race.

First, there arent any games being played. Its not nearly so simple as just just plug in a 2.4 gig module and go fly. There isa LOT of new technology involved in Spektrum. It cant be reverse engineered very easily since a lot of the technology is in the software that operates the DSM sytem, not the hardware alone.

As for the benefits, oh my gosh. Its so much more than just the response rate, whch is super fast. I just got back from an airshow in Guadalajara Mexico. Great show and a beautiful field. Unfortuantely the field is the most hostile environment I have ever flown at for radio interference. I saw issues with all brands of radios at this field. Including one I had in my 2002 TOC model (which is owned by a friend there) , where I was lucky to get it back on the ground. A BVM bandit crashed with a 14MZ in it ,etc etc.
It is accepted at this field that if you fly low off the ends of the runway, you will get lock-outs.
OK, I flew several flights on a FuntanaX with the DX7 installed. Did point rolls off of takeoff just a few feet off the gound till it was hard to see. Then installed it in a DA-100 powered Extra and did the same thing.
Seeing is believeing. It worked perfectly.
Another advantage is that it is immune to any aircraft generated noise, ie. ignition system, ecu, metal to metal contact etc.
Of course, no freq pins and you cant get "shot down". It is amazing!!!!

When I get to AZ tomorrow, I plan to pull out the 72mHz system and install DX7 in the F1 giant scale racer to fly it in the champ race. Its about 190mph on the course. I have no worries about using DX7 even in this model.

BTW, I dont get paid to say this stuff, and honestly I wouldnt if I didnt believe in the system. I'm just that excited about the Spektrum system.

RE: Spektrum DX-7
 

Mike,

Glad to hear that it will be tested in a screamer. I like the technology, it is great.

And, it is the END GAME as far as our radio link is concerned. It will be in RTF packages and defacto standard in a few years.

Some of us are having a hard time knowing that after purchasing a high end TX, we may need to 86 it, and get another to use the best technology.

IF and I say IF modules or retro-fits of the current high-enders can happen, it will. Time is on the consumers side. Spektrum has made everyone take notice. Good things happen next.

I will use my DX6 all dome season, watching, reading.........waiting.

RE: Spektrum DX-7
 

I hope they can bring this technology to a 12 or more channel system to use with jets and scale planes. As long as the programing and channels are there to use, it looks good. I do not need pictures, music, touch screens, etc to fly my planes.

RE: Spektrum DX-7
 

So once and for all, are you saying 2.4 modules for existing JR transmitters are never coming? Simple question begging for a straight forward answer.

RE: Spektrum DX-7
 

YES! Definitely! Look around at what goes on!

RE: Spektrum DX-7
 

I am more interested in how he is going to get teh DX-7 to work for IMAC without all the mixes.
I guess if matchboxes are used all around, then a simple 4 channel radio can be used with a couple of mixes built in.

Mike, thanks for the input. I know you can't share new or pre-release information, but it would be nice to know what is in the works!
Thanks and good luck at the races!

RE: Spektrum DX-7
 

Your absolutely right ,Dan.I hadn't considered the incorrect model lockout feature.However,they state that the transmitter will work with the DX6's receivers.So,I assume the Model data sent isn't prohibitive.The feature would have to be incorporated into the transmitter receiving the DX7 rf section,or be disabled in the receiver(the latter might not be too difficult).
My point however,was that the Spread Spectrum technology shouldn't be incompatible with a "Module" based system for current transmitters.Until they threw the "Lockout" unless the correct model is selected feature in,the system would ork perfectly as such.

RE: Spektrum DX-7
 

I would ASS-U-ME that the DX7 can transmit either protocol. They didn't say that you had to tell the DX7 xmitter which receiver you are using. If the model I.D. command is a command that the AR6000 ignores then you wouldn't have to tell it.

We'll know more when we can get our hands on one.

RE: Spektrum DX-7
 

The module issue isnt an evasive one. I dont know the answer.

For an IMAC airplane, I really dont use a lot of mixes. Usually one for ail, one for dual elev. Then a few free mixes for pitch and roll couple mixing if needed. The DX-7 has flapperon mix, and 6 p-mixes. Plenty for an IMAC model actually.

The GS racer actually presented more of an issue since it uses 8 channels, (2 x ail, 2 x elev, rudd, thrott, mixture and pressure dump) with a curve mix for active mixture control. I ended using a Matchbox for aileron and the rest was simple. Did have t use a 3 point mix instead of a curve for mixture but I lev will work fine.

RE: Spektrum DX-7
 

Mike,
It sounds good.
I will have to wait until next year to see what additional products are released.
With the number of park flyers in my area, and congestion from construction and traffic, I worry about being locked or jammed.
I am a Futaba guy but I do appreciate all the work that JR and Spektrum are doing in this area.
Please pass our collective thank you's to the proper people.

RE: Spektrum DX-7
 

I think the DX7 is a good step forward from Spektrum. I have the DX6 right now and use it on all my Electric Helis. I also use a Futaba 9C for my giant scale warbirds.

I know too many people having to do multiple glitch fighting measures on their helis with their 72Mhz radios and I have seen too many cases and reports of 72Mhz planes being shot down accidentally or deliberately. With 2.4G technology, glitch busting and shootdowns are mostly eliminated. Dumb thumbs and equipment failure should be the only cause for crashes now.

I definitely plan on buying a DX7 to use on most of my Giants. (Does anyone want a good deal on a bunch of Futaba 72Mhz PCM receivers???)

It would be nice if Spektrum (or JR) follows up the DX7 with a high end (9 to 16 channel) model as a 10X replacement.

RE: Spektrum DX-7
 

k3 valley flyer

You make some apparently valid points. I'm not so certain that your conclusion is valid.

For example: Why introduce the new technology in a very moderately priced radio? -----and one which will accept the existing myriad of servos in use -- including the competition's.

I would have assumed that it would have gone in to the "Top of the Line" gear. Then slowly work it down to the level of the DX7. That would certainly aim at the "money isn't the problem" group.

I fly the 10X (being retired for more than a decade I can assure you that money IS a problem)and do not feel as if I have been at all manipulated. Last time I looked, the 10X was about twice the price of the 9303.

This incidentally IS "Spektrum" ------ not a sole JR offering though I believe it is manufactured by JR for Horizon.

Regarding 'shoot downs' there are two varieties ----- off field and on field.
I have flown on six meters for 30 plus years yet had a total shoot down (off field variety) about a year ago.
I switched to 72 MHz PLL synthesized as times have changed and the protection I had all those years on six is NOT there today.
Today there are recently licensed six meter operators out there who only know where the on/off switch is located.

I've been a JR user since they introduced the Unlimited Eight and that was a lot of years ago. I've been flying R/C for 47+ years.
I may not have seen it "all" but I've come pretty close. I applaud the introduction of the DX7 and its technology ------ even if it obsoletes all my 10X equipment ----(it won't as it is rock solid and nearly bullet proof in the present form)

Perhaps it is my age, but I don't feel that everyone (particularly Horizon ---- who are a total 'CLASS ACT') are out to shaft me or to get my money under any ulterior motive!

I would prefer that a module/Rx combo was available because I like my 10X ----- I'll simply have to wait and see.
On retirement income (that's an oxymoron incidentally) I can still afford the DX7 if I feel so motivated.

This is my view of the situation-------simply different than yours.

RE: Spektrum DX-7
 

I still would like to have some feedback with details on Mike's installation of the DX-7 in a 40% aircraft.

RE: Spektrum DX-7
 

I have been holding off buying a DX6 until "full range with a versatil computer radio came along." I'm leaning toward buying a couple of DX6 recievers for park flyers that are just about ready. (I am getting back into RC after a hiatus of 40 years.) The DX6 seems to be all that is need for a park flyer and I can always upgrade to the DX7 Tx later. Is the power level greater on the DX7 Tx greater or does most of the range improvement come from the dual diversity receivers? Thanks

RE: Spektrum DX-7
 

I heard the Spektrum DX7 is using cell phone technology. It finds a open channel and locks on it. Then there is something about it will only talk to your receiver by some code. Not sure on this. tis what I heard on the street/RC Field. Capt,n

RE: Spektrum DX-7
 

Not quite.
It is using cordless phone technology or basically Spread Spectrum at 2.4ghz technology.

RE: Spektrum DX-7
 

I'm getting one, I have the DX3 Transmitter for my RC cars and I love it.

All this 2.4GHZ tech all over the place and I have yet to be locked out, I have always found a channel.

802.11b
802.11g
802.11n
bluetooth

and I don't know what all use these same channels

If I remember correctly there are 80 channels available

RE: Spektrum DX-7
 

My DX6 worked great. Gonna use one again for indoor season.

I just won;t upgrade in baby steps.

I will skip the DX7.

RE: Spektrum DX-7
 

There are a lot more than 80 channels.
If I remember correcly it is like 100,000 channels all with full bandwidth.
With the interference range around 5 miles there should be plenty of available channels.

RE: Spektrum DX-7
 

Geistware, if I remember correctly, the DX6 worked by choosing two of 80 available channels. When and if forty different flyers had their transmitters turned on, no more frequencys would be available and the forty first flyers transmitter would not operate after scanning the eighty frequencies and finding them all full. I assume the DX7 works the same way, I'm sure someone will correct me if I assumed wrong.

RE: Spektrum DX-7
 

THE FCC has specidied the frequency band of 2400MHz to 2483.5MHz for SS. This is 83.5mhz range.
If we use our existing systems as an example, then we have a spacing of 20,000hz
If they use this same spacing through the entire range then we will have 83,500,000/20,000 possible channels.
This comes to 4175 possible combinations. So my Statement of 100,000 channels is wrong. I do stand corrected.