Camel

Need some advice please. Spektrum AR 9000 plus extra remote ie 4 rxs total. Tried in a large foamie to check out flight logger numbers. No surprises all very good.
Next a 88 Yak 50cc wood build. Fades and frame losses significantly higher but within the quoted normal range.

3 Metre comp arf Classic extra, not much carbon just renforced formers. Numbers now well outside given range. Main rx moved to top of canopy and moved to all poss angles, remotes also moved to every likely place including tapeing one outside the fuz. Improvments but still much higher than reccomended.

Tried all again with a second AR 9000 set with similar results.

So whilst I'm happy to fly the 88 Yak the 3M extra will need some more work, can any one help please,?
some one must of been here already!

How long does a hold last, as in once there is a good signal being picked up how long does the rx tgake to come out of failsafe. I checked by taking a long walk pushing the bind/ range check button far enough away for the system to go into failsafe then releasing. it seemed to be the same as turning off the tx about 3 secs which is rather scary!

Finaly rumour has it that 2.4 can suffer when within close trange of an airport using certain radars any one heard of this?

cheers
Robin

Panzlflyer

My Feedback: (15)

mine all recover almost instantly, I posted my results somewhere here but I recall on the 35% and 28% the fades were between 8 and max 40 (500 being max) only holds were induced by a range check, no frames lost. No CF in mine to speak of.

dribbe

Hi,

Could you please post some numbers so we can understand your situation a bit better?
A fades?
B fades?
L fades?
R fades?
Frames?
Holds?

How far did you get with the range test?

How long is the flight (for the data)? Are you going FAR, or just average distances.
Which Tx or Module are you using?

Pictures of the install are very helpful as well.
For best results, orient the Tx antenna so it does not often point directly at the model (IMO).

Have Fun,
David

Camel

David thanks for the reply,

Dont have the know how to post photos how does one do this?

Main rx was for 1st flight in cetre level with wings at trailing edge with rx orientated across the fuse ie servo pins pointing towards the left side of plane. Left remote on left side upper turtle deck approx 6 inches back from rear of canopy with aerial horizontal Right remote opposite side aerial vertical.

A 255 B 865 L 304 R 96 F 61 H 0

Moved main rx up as far as poss into canopy still in centre and now with body pointing up ie pins down and other ant towards rt side also rotated left remote to vertical.

A225 B662 L 250 R 184 F 11 this seemed very promising so flew again

A 255 B 486 L 216 R 248 F 32 decided to tape the R remote outside similar position just behind trailing edge

A 255 B647 L 162 R 94 F 10 promising so one more flight

A 255 B 647 L 322 R 454 F 86 H 0

this concerned me so tried the other 9000 and swapped over the remotes for new ones. flew once wher the frame losses were 63 and thats as far as I've got. Spoke to Spektrum Uk who replaced both rxs by return but could offer no help.

Im aware of how unlikely the numbers of A 255 being repeated and also A and B being the same on last two flights. Im told 255 being one less than 256 is something to do with 8 bit information? beyond me that one.

Flight times are all 15 mins or very close, distances range from close in to average IMAC type "box" I tried to keep all flights similar in content.
Lots of rolling.

Range tests were done as per the manual with and without the motor running and at various rpm and from all around the plane ie the aircraft was rortated 360 and stopped at 4 points all was well, did not however establish a distance at which the tx went into fail safe is this needed?

Obviously if these frame losses are spread over the flight and nowhere together then perhaps this is ok however there is no way to tell.

Thanks panzlflyer for the info I take it you have experienced a hold then, what happened?

My plan right now is to make a carrier to mount a remote rx away from the fuse by an adjustable distance then perhaps have one top and bottom or left and right so at least one would be in view of the tx all the time

dribbe

Hi,

I will take a little time to review this... but as a first blush....

Your numbers are toward the high end, but your flights are very long. Most of my data is for flights of 7-9 minutes, and if I scale it up to 15, I would say this is medium to high (and not out of a safe range).
To boil it down, in your example I would rate the frames of 0-15 is awesome, 15-30 as very good, 30-60 as ok, and 60-90 as acceptable, but a bit high. (It is all somewhat relative, but these are my personal feelings based on experience.... I have not seen a hold yet personally, and have never percieved a control hesitation.)

Keep in mind that it takes 44 frames IN A ROW to get a Hold (failsafe).
I would relocate or change the height or plane (and/or tilt) of an Rx with frames in the 200+ range to see if you can do better. (Is it behind a ton of wires? thick carbon or metal spar? In the plane of a major structure or carbon wings?)

Overall, despite the data losses, you are getting very good performace from the system. (This is the reason we offer an Rx with 4 rx's . Multi-paths/orientations/redundency.

Your WORST case of 86 frames over 15 minutes is 5.7 frames per minute of the approximate 3000 (about 50*60) frames per minute. (less than 2 out of every thousand). (Or about one single frame (1/50 of a second) every 10 seconds!! I don't think anyone could ever feel this and expect in greatly out performs traditional systems.)

Look to improve where you can, but keep in mind it is working quite well even though it does not appear to be working as well as 'average'.

Range test is quite important... you will see a point where the data is lost very dramatically (it still is hard to get a hold). This is the best indicator of proper Tx operation and/or power. (40-70 paces??)

Pictures would be great! look for the Click to upload images (maybe easier to find if you edit a post in some cases??)

What is your Tx/Module/system?

(I cannot explain the somewhat odd results for A and B number repeats.... was this the same Rx central unit, or two different ones?)

Have Fun,
David

Panzlflyer

My Feedback: (15)

Are the figures taken during a flight AND range test?
My figures are for a flight and no range test, I would assume that the figures would be higher if you included the results of a range test.
I have not had a hold in flight only simulated one by turning off TX and it resumes instantly.
As far as antenna I have the remotes at 90 and 45 degrees to the fuse as per Danny at JR.
Ive got that many flight on them now that I dont check the data if I induce a failure then surfaces go to neutral and throttle to idle but it resumes instantly, in fact I just checked fasilsafe on a new one this afternoon.
I personally would not be happy with the high number of Fades.

dribbe

I am working under the assumption that the #'s are for a flight.

I think I have inferred that I would not be satisfied with the #'s either, and would try to do better.
(The lower numbers would be acceptable IMHO if they were the 'slightly worse than average' ones.)

It is common to see A and B higher than the others, but I would be happier seeing lower numbers.

David

Camel

David
thanks for your time, not had much meself recently to experiment with the big one however the 88 Yak has had several more flights with rxs moved a little from the first placing and the results are very good all for 15 min plus flights and worst case was 3 frame losses mostly zero.

Have taken the time to satisfy myself with the time scales involved in going into and recovering from a hold using my large foamie on the deck and the recovery seems to be very quick so am happy with this aspect now.

Also have checked out flying same foamie, with ar 9000 and 2 remotes, very high directly over head.

Tried this first with the tx aerial straight and got significant fades and some frame losses still ok though just more than the usual very low numbers recorded from the foamie. Then with the tx aerial at 90 degrees this time the fades etc were much less almost as good as a close in flight with the aerial in normal position. Done over several flights and with consistent results. Says quite a lot for the idea of not pointing the tx directly at the plane. With this in mind I intend to try flying the Yak with the tx pointing at right angles to flight path and compare with some flights where I stand in my usual position see if this makes a difference to fades.

I have taken all your comments re fades frames and time scale and feel some what reassured ,enough to carry on testing at least and have made sure the rxs are best placed as I can. If the frame losses are spread out then yes no real issue it was just unerving to see 86 when 44 can cause a hold, no time base so no way to see exactly whats going on, Any way to add a way to record hits versus time?

My plan now is to mount one rx externaly on a former which I can use to adjust orintation and distance from fuz, then see how we get on.

Tx is JR PCM 10 with module, UK version so we may be a little down on power output compared to the USA

The numbers were for flights not range checks

Range checks were carried out at 4 quarters with and with out engine running and at various rpm. All done to a generous 30 paces have not as yet tried monitoring for fades as the distance is increased. Will do this next time out.

Worst case numbers have always been fron the main rx ie A and B by the way which one is A and B?

The main rx was moved up into the canopy area as high as poss which did help but not a great deal

Will try with the pics next time, may be a day or two yet though,

Thanks once again
Robin [8D]

PS Ryan here at spektrum Uk has been great and says you are the man with regards to this kit so no pressure!!

rbentley

My Feedback: (1)

On a related matter. Does anyone know why I makinf a change in transmitter antena position would significantly reduce the number of fades, yet increase the number of frame losses from 20 to 32?

Flight #1: A-237, B-142, L-85, R-173, F-20, H-0
Flight #2: A-42, B-60, L-55, R-48, F-33, H-0

Chris Moon

My Feedback: (8)

I think the differences in numbers is due to the 2 frequencies that the radio chooses each flight. Some may be noisier at a distance than others. We have noticed significant differences in data losses as well between flights with no changes made to the setuo or tx antenna between flights. In any case, we have never seen nor recorded any "holds" and never had any losses of control.

Camel

Further to my last post I have now had another 5 hours worth of flying now with the 88" Yak AR 9000 plus 2 remotes and generaly the numbers are all in Daves awsome bracket with the odd high returns, as in approx once every 6 flights at 10 mins now I have seen frame losses of 26, 42,40, 42, and worst case 76.
These were in amongst averages of single figures and zeroes.

Also with regard to the tx locking on to freqs at each turn on I have been flying pairs of 10 mins flights not turning off the tx between just taking the figures turning the rx off and on checking the logger says zero and off for another 10 mins. The numbers vary as before with some of the highest being immediatly after low.

Just to upset the confidence last week my buddy lost his 87" yak. 3rd flight on ar 7000 jr module in a 9x or the 9303 in USA.

All checked out as per no worries, fail safe checked from high throttle setting(throttle closed!!), range good, this plane has been flying superbly for 2 years on 35 mhz. Slow reverse cubans close in over the strip at 45 degree down line point engine went to full throttle and no response from the plane. Took a long time to pick up the peices. radio returned to spektrum uk who are replacing and have sent kit back to USA for checking.

On checking post mortem the rx was found to work ok most of the time with approx 1 in 5 resulting in lights on servos holding but no response from tx this was with the tx on all the time. The fail safe was also ok, when the rx worked, and drove the throttle closed. So something sent the thr wide open and poss an apparent hold on the rest.

As you can imagine this has not done a lot for confidence amongst us sceptical brits! I know at least 5 people that day who are now not going ahead with 2.4 and waitng for futabas up market kit, trouble is these things get blown up become rumour then fact. partcularly when historicaly there is very rarely any feedback from manufacturers other than no fault found.

Have not had chance yet to try the 3M extra again, although I have finished the mounting for a remote externaly with adjustable orientation.

I have a couple of questions for you Dave please.

1. the figures given in the manual are some what different from those you quote can you confirm what is acceptable and what is not please for a given time?

2. The main rx has 1/2 aerials why? these are the rxs which virtualy always record twice as many fades. For large planes the best system may be to have all the rxs remote and the main body/processor could then be easily mounted in a more traditional position for servo wiring and the remotes, now 4, could be positioned in more of the optimum points. Looking at my results in the 3metre extra this would solve the issue as nearly all the worst hits are on the main rxs A & B.

3. What is the maximum length of remote extesion cable I can use? I know 36" is available but a remote on top of the fin or at a wing tip would be optimum, thats where all the sensitive aerials are situated on full size aircraft.

4. More of a suggestion realy, any chance of having a logger which records fades etc versus a time base, down load to a memory stick/pc.
One could then see exactly what is going on, how close these frame losses are. Be a huge confidenc booster.

Ignorance was bliss!


cheers
Robin