DSM2 / JR / Spektrum Guru's....
 

I'm going to say this first off..

DO NOT say ANYTHING about "go to futaba". I dont wan't to hear it, i've got my reasons for not using futaba. If you like it, i'm glad for you, but personally they will never see a dime of my money again after the way they treated me with the last radio system i owned from them. so please, do me and anyone else who may be interested in this thread a favor and don't start another brand war.


So i have been using the Spektrum / JR DSM2 technology for the past 4 years w/o many incidents. I have always been careful to keep RF noise critical components separated (just like you would with 72) and have been rewarded with very low antenna loss counts on my models (less than 100 between 4 antenna's in the jets). Today was the first flight of the season for my Euro-sport after some modifications and changes (added speed-brake, relocation of fuel-pump, UAT, etc), electrically everything has stayed the same.
For the past 2 season's the most antenna packet loss' this airplane has ever seen was 150ish between the 4. Today on the flight, I had Zero packet losses for all the antennas (3, one of them went kaput on me), Zero Fades, and 422 Holds, all in the 8 minute flight routine.
I have always been under the impression a "hold" is essentially a "fail-safe". And in order to get a hold, you have to have a consecutive number of Fades, and in order to have a Fade(s) you have to have consecutive packet loss' between all of the antenna's.

I never once experienced a loss of control, or felt the airplane was un-responsive due to a fail-safe condition. None of the rx's were flashing indicating a momentary loss of power, and the turbine never shut down either (yes, it is programmed to shut down during a fail-safe).

Tx - JR 11X
Rx- spektrum AR9100
RX batts- dual 2s 2300mah A123's

Anyone have any input or thoughts? I'm planning to put in a call to the horizon tech department tomorrow to get their input on it, but figured I would post up here to see if anyone had any thoughts.

RE: DSM2 / JR / Spektrum Guru's....
 

That part of your message is the most important part. I have flown DSM2 for 4 years now and never plug in the little screen as it tends to cause worries that when all is going well. Keep flying and get rid of that little screen I say. We tend to over analyse things and all the new tech gives us the opportunity to do this.

Lot to be said for not knowing some times.

Dennis

RE: DSM2 / JR / Spektrum Guru's....
 

Hi Invertmast,

I once had exactly the same situation as you on my flash. The Gurus here told me it most likely happened while taxing out or inn. The reason for this could be some object between the Tx and the plane which mostly we do not notice while taxing. In the air all should be good.
Another reason Dave.W told me was if your Tx is too close to the plane while switching on the system.

I too was worried at first, but few more flights with numbers going back to normal has got me at ease.

Chatty.

RE: DSM2 / JR / Spektrum Guru's....
 

I see swings in the numbers from flight to flight. I have never had any control issues though. I believe (my only RF knowledge was gained in a Holiday Inn Express) that the differences between flights is related to the DSM2 locking in on different channels each flight. From one flight to the next the next it might pick a "dirty" channel which causes the problem. I try to place a satellite on each "corner" nose,tail,each wing to separate them by as much as possible. One flight I may have single digit fades and the next flight fades of 100 or so. I used to worry about it but not anymore.

RE: DSM2 / JR / Spektrum Guru's....
 

Thomas,

Just a thought, but since you re-located the pump and UAT, you most likely are seeing the results of that. You may want to shuffle a couple satellites, and do some range-checks to see if you can get "acceptable" numbers.

RE: DSM2 / JR / Spektrum Guru's....
 

If you don't want Futaba comments or too start a brand war, why start one with your own comments. :eek:

Mike

RE: DSM2 / JR / Spektrum Guru's....
 

2 years without problem with DSM2

last month crashed my vampire due total lockout

mx-22 + 12ch module dsm2 + ar12000 with 3 satellite was the cionfiguration

700 over fades each antenna during succesful test with foam easy glider

Changed tx module and lipo-pack in the transmitter with new LiFePo4 Hyperion 9.9v

now test with same setup and finally under 30 fades each antenna...000f 000h
spektrum analyzer give me free 2.4ghz band, no jammer and other interference


maybe over loaded tx module with 3s lipo pack with over 12volt:eek:

RE: DSM2 / JR / Spektrum Guru's....
 

George,
That is the odd thing. I did a range check with the plane about 30 paces away from the tx w/ the range check button pressed. I had Zero on all of the antenna's, fades and holds. I actually moved the pump off of the bottom of the tray under the canopy, back about 4" to the fuselage side. The uat was moved from behind the nose gear plate to the top spine just aft of the speed brake.

The thing that is most perplexing to me, is the high number of holds, with zeros on everything else.

The only thing that does make sense, is the tx was beside the airplane when i powered it up, so it could have just been to close during power up like someone else mentioned.

RE: DSM2 / JR / Spektrum Guru's....
 

Because i knew someone no matter what would throw some snide remark about switching brands, just like someone always done when it involves a spektrum/ jr question. Soooo

Thank yyyyou for stiring the pot, i knew to expect some futaba user to have to chime in.

RE: DSM2 / JR / Spektrum Guru's....
 

I fly JR, Spektrum and Futaba so am not biased in any way, your inflammatory statement in the last paragraph of your post is just the way war's are started, stating that you don't want to do something and make a statement that does exactly that, stating that Futaba did not treat you correctly is going to put the back up of every Futaba user on here, if you did not want any Futaba comments then you should have left your personnel comments out and just stated that you do not want to change to Futaba so please keep any post confined to JR and Spektrum and do not suggest that you change to Futaba thank you, that may have done the trick instead of having a pop at Futaba or its users.

Mike

RE: DSM2 / JR / Spektrum Guru's....
 

Here some test value

table n.1 = Lifepo4 pack+new module
table n.2 = Lipo Pack+defect module

RE: DSM2 / JR / Spektrum Guru's....
 

I gotcha! Do a little more testing, I'm sure you'll get it figured out and the good news is that even with the holds, you didn't experience any problems.

P.S. I know you know, I'm a Futaba user.;):D

RE: DSM2 / JR / Spektrum Guru's....
 

Ill just agree to disagree to keep the thread on track.

RE: DSM2 / JR / Spektrum Guru's....
 

Thomas,

I'm starting to use/learn Futaba lately, but I'm by no means a brand loyalist (and still can't figure out why some people fall for that child-psychology), but I'm interested in what happened with your Futaba experience. You can PM me if you don't want to do it here.

RE: DSM2 / JR / Spektrum Guru's....
 

Yea i know... i was a loyal futaba user for over 16 years.... honestly, i probably would try their systems, if great planes wasnt their distributer. I have more issues with them than futaba.

RE: DSM2 / JR / Spektrum Guru's....
 

I am having sort of the same issue with my Flash. It has a Spektrum powersafe Evolution in it with a flightlog permanently attached to it. I check before and after every flight and my antenna fades are more or less always the same. But for my "A" reciever it is to much the same, it reads 255 antenna fades on each flight, always exactly 255. On the other antennas it varies from 150 to as much as 600, but frame losses are always below 20.
During handling in the pit lane those numbers can skyrocket if someone walks between the TX and the RX, that's why I check my numbers again right before taxiing out.

Bart.

EDIT: Chrigui, I see in your log file that you also have some 255's on your "A" reciever.

RE: DSM2 / JR / Spektrum Guru's....
 

sent you a pm.

RE: DSM2 / JR / Spektrum Guru's....
 

Hi,

That's what I'm talking about. Why? Why does it put anyone's back up? Because I've had a good experience with a product, I'm going to take it personally when another person has a bad experience and says so? I don't get that.

RE: DSM2 / JR / Spektrum Guru's....
 

Brand loyalty seems to be something that most people take to heart, if you don't want to hear any negative comments about something else that people use don't make any, be constructive.

Mike

RE: DSM2 / JR / Spektrum Guru's....
 

Understandable, but..
I never made a negative comment about futaba, i said i had a bad experience with them and they would not see another dime from me.

RE: DSM2 / JR / Spektrum Guru's....
 

I wonder if there is not some sort of glitch in the performance logging in the JR/ Spektrum receivers. I had a similar problem only with frame losses in my Flash with a AR9000 receiver. I had approximately 50 flights on my Flash before i purchased a data logger last fall. I borrowed a data logger 2 years ago and checked it on the first couple of flights and all the numbers were good. When I checked it later with my own data logger, it showed 999 frame losses after an 8 min flight. Horizon sent me a new data logger but I still got 999 frame losses. I returned the receiver and it was returned after a firmware update. This time I did not fly but taxied to the end of the runway and back. I hooked up the data logger and it displayed 178 frame losses and counting at a rate of approximately 1 per second. A buddy then loaned me a JR 1221 and similar test were done with no frame losses and very few fades.
I returned the AR9000 a second time. It was not repaired but Horizon went about and beyond what i expected them to do to make things right.

RE: DSM2 / JR / Spektrum Guru's....
 

Ok guys, this is starting to get off track. The OP stated that this thread isn't about which brand of radio is the best. Yes he could probably have gone without taking a shot at one brand of radio, but that doesn't give everybody permission to take the thread off topic. This thread is requesting technical help concerning one specific brand of radio, let's keep the topic centered on that. If you can help him out then by all means please do so. But if you simply want to fuel a "brand war" then let's skip posting here as any more will simply be deleted.

Thanks for your cooperation

Ken

RE: DSM2 / JR / Spektrum Guru's....
 

I would change out the data logger. I have had one go bad on me and gave me all kinds of whacked out readings...if you have no fades etc and only holds indicated, yet no feeling of loos of control you have an indication problem. Change the logger....

RE: DSM2 / JR / Spektrum Guru's....
 

Can the 11X be upgraded to DSMX? I wonder if you would get these same results with a DSMX radio and receiver setup. If DSMX works as advertised it should weed out the potential weakness of DSM2 "pick-and-stick."

RE: DSM2 / JR / Spektrum Guru's....
 

It can, but i decided not to do that upgrade due to it being new.