FLIGHT REPORT Comp-arf 3.1SX and Spektrum

[notorious_benny]

I would just like to share my initial experiences using the spektrum AR9000 air module and Rx in my composite-arf super extra.

After having a big hit (and scare!!) on 36Mhz, followed by unexplainably and unrepeatble poor range tests on my 140 flight old super extra I decided to bite the bullet and try out the Spetrum air mod in my JR 10x radio with the AR9000 Rx and extra satellite Rx.

The results I thought might be interesting to share, as the Super extra has all the supposed anti 2.4Ghx stuff on board.
Loads of carbon, carbon lattice fuselage, big fuel tank, 157CS Twin Spark motor, 32 inch Carbon prop, etc etc.

I used the spektrum flight log on each flight to evaluate the integrity of the link between Tx and model.

For reference, on the flight log A, B, L and R stand for antenna fades on the corresponding antenna. A fade is where that particular antenna loses a packet of information.
F, stands for Frame losses, a frame loss occurs when there is simultaneous fades on all antennas causing the entire 'rx system' to lose that packet of information.
Finally, H stands for hold. A hold occurs when 45 simultaneous frames are lost, it takes apporximately 1 second to lose 45 frames in a row. This will cause a failsafe situation.

Flight 1, 5 minutes.
Consisted of general aerobatics, and low passes, I did not fly particularly deep or high. But did perform rolling circles to put the model in unusual attitudes.

Results......

A 95
B 21
L 12
R 4
F zero!!
H zero!!

all looked good, checked the voltage's and straight into flight 2.........

Flight 2, 11 minutes.
Consisted of Unlimited sequence practice, this time the model was flown deep and high. Including deep rolling circles.

Results.......

A 255
B 256
L 93
R 14
F 2
H zero!!

Again quite happy with the results only 2 frames lost. Antenna's A and B are the worst performers but I expected this as they are buried fairly deep in the fuse.

Flight 3, 13 minutes.
This time, feeling more confident in the system I flew bigger, and very high on a few manouvers whilst practising the Unlimited sequence. Also ended up quite deep out to the side of the box on a few occasions.

Results.....
A 255
B 261
L 243
R 025
F 13
H zero!!

Again, well within Spektrums guidelines of 20 frames lost per flight....

Flight 4, 13 minutes.
More unlimited practice, I got muddled during the roller and ended up flying a long way out the back of the box, very deep and fairly low. I was sharing the sky with a couple of fullsize FA/18 hornets and a fullsize chopper.....!
I also had some trouble linking the Rx this time, it took 4 goes, in the end I moved the model away from the metal pit shed I was under and everything linked up.

Results......
A 255
B 361
L 286
R 93
F 33
H zero!!

Quite a few more frames and fades on this flight..... I realised after landing that on this flight I had the Tx antenna pointed forwards a little compared to previous flights.
I bent it up straight, so while holding the Tx the end of the Antenna is pointing straight at my forehead and flew again.......

Flight 5, 13 minutes.
This time I flew the Advanced sequence which I am much more familiar with. At the end of the flight I also flew two big, deep and fairly low knife edge circles. Something that the 36Mhz would sometimes get hit whilst doing.
Again 'sharing' the sky with a pair of FA/18's roaring around well above my altitude.

Results.......
A 255
B 133
L 144
R 32
F 1
H zero again!

Seems that bending the Tx antenna right up so it is looking at you gives the best performance, only lost 1 frame the entire flight!!

Thoughts.

Those who have been paying attention this far will have noticed that the number of fades on antenna A was always 255 on flights 2-5. I did a range test on the ground to force a couple of holds and checked the logger. Seems the Rx only logs fades on antenna A up to 255.... hmmm intersting, I will plug in my other AR 9000 and see if the same thing occurs.
Having notced that, all the other counts were varying, and the F and H counts are the one's I am most interested in

I have read, but not really believed that people running the Module upgrade feel the model is more responsive than with PCM.
However, I initially found myself over controlling the model and finished up having to dialling down the rates a little and adding a little expo on ailerons and elevators. This is a model that I have had set up the way I like it for some time now, so maybe there is some truth that converting PPM to SS is a little faster than straight PCM.
I cant wait to get my hands on the new 'native' 2.4 Ghz Tx's coming out, they should give awesome response.

The main gripe I have with the setup so far is the poor balance my 10x has on the neck strap. I would also like to see my data logger telling me haw many fades I have truly suffered on antenna A.

From todays tests I feel mostly confident in the Spektrum system, I am going to enjoy being able to come to the field and not worry about some old guy with a trainer and a 100 buck radio shooting me down.

I hope someone finds this information helpful and informative.

[notorious_benny]

Heres a few photos of where my Rx's are placed and the upgrade of the 10x.

Forgot to add that the power system consists of 2 x Fromeco 4800 peerless Li-ion packs, running through an Emcotec DPSI RV that supplies a nice clean 6 volts to the AR 9000.

The model has 9 Hitec 5955 servos and a JR DS 811 on throttle.

[feral63]

sorry benny got half way through reading this and lost interest. i'll wait for the movie to come out.

[notorious_benny]

	Quote: Originally Posted by feral63
	sorry benny got half way through reading this and lost interest. i'll wait for the movie to come out.

Sorry Feral, an analytical report on anything is always going to be overload for your Corona coddled mind!!

[Jamieman]

Done well Benny.
Hope it solves your prob.

[Stu_D]

	Quote: Originally Posted by feral63
	sorry benny got half way through reading this and lost interest. i'll wait for the movie to come out.

LOL feral

Benny , Looks as thought you had about the same results as me . The only hold
I ever had was way way way deep and very high to the left and it was only for
about one second . Felt like ages when its on hold though .

Now keep a close eye on the batts , thats where I ran in to trouble . I still dont
know what the cause of my prob was but I suspect the LiPo were old and at the
end of their life . Just keep a log of the amps used per flight and see what if any
changes there has been between the 36 and the 2.4 .

Stu

[notorious_benny]

Hi Stu. I am not able to record actual amperage put back into my Fromeco's as the fromeco charger dosnt give this information.

However the voltage readings under load on both Rx batts after 4 or 5 flights were consistent with what I would expect under normal circumstances.

[RustyTumbles]

	Quote: Originally Posted by feral63
	sorry benny got half way through reading this and lost interest. i'll wait for the movie to come out.

Halfway, who are you kidding. I bet you only got 2 maybe 3 sentences in.

[RustyTumbles]

Glad it when well for ya benny. I'm still keen on the DX7 setup.

[dick hanson]

From todays tests I feel mostly confident in the Spektrum system, I am going to enjoy being able to come to the field and not worry about some old guy with a trainer and a 100 buck radio shooting me down


Interesting --the typical problem here --a young guy with a recently aquired CHEAP BUY- 72 .xxx radio -maybe has to do with which side of the globe you fly on.

[MetHerInBaghdad]

Benny,

Thanks for this update. I like seeing the actual data on these systems, instead of just pure opinions about how great or how sucky they are.

I think that JR/Spektrum/Futaba spend a lot of time honing these systems and testing them, but they can't always catch all variables that could line up to smite us ... so we have to sort them out as we live and learn in daily conditions.

I appreciate the wonderful reports such as yours.

--james vanwinkle

[GooseF22]

Benny
maybe elevate your main receiver and see if the frames lower? Otherwise looking good.

[feral63]

ok ok. you know me well enough. i knew it was going to be one of benny's long winded speeches.

	Quote: Originally Posted by RustyTumbles
	Halfway, who are you kidding. I bet you only got 2 maybe 3 sentences in.

[notorious_benny]

Goose, thanks for the advice. I was thinking of moving the main rx to the opposite side of the fuse, maybe simply elevating it might be enough to improve its individual performance.

Had two more flights today, full unlimited practce. Flight one yeilded zeros frame losses and flight two recorded 4 frame losses.
The antenna's on the main rx are the worst performing, I will be looking into moving it for future flights.

[GooseF22]

NB
at the jet meet this weekend, the best performing boxes were elevated or mounted vertically up in the canopy area, or at least midway up.

When I get a chance, I will post my install. It passsed all my ground tests with less than 5 fades. Havent flown it due to a motor issue....soon though.