Roger Shipley

My Feedback: (35)

I am in a state of confusion regarding which way to proceed between the​ DSMX or DMSS​
Transmitter/Receiver Systems? I upgraded my A-10 receiver last winter (2014/2015) from a JR1221X DSM to a Spektrum AR12120X DSM. I continued using my JR 12X transmitter that was updated and validated by Horizon in November 2011.

Everything went well without a single glitch until Saturday at Jets Over Kentucky last July.
One Minute plus left for the 9[SUP]th[/SUP] flight 6 planes in the air with others waiting take-off clearance.
Going straight away & level from our flight station with full power on a pair of KT 140s.
Landing plan…. a pull-up to inverted, ˝ roll right to upright (Immelman), then right bank to enter the landing pattern.
The pull-up only resulted in a slight up trend then a momentary straight and level before an instant absolute nose down crashing into a field pond. There was no other movements in the attitude of the wart hog from my transmitter inputs.

Opinions….we believe (several on-site testimonials) the Rx entered fail safe settings straight & level, turbines to shut-down.

Notes: It was our first flight on Saturday, charged all 4 batteries, filled both fuel cells & air tanks....Tx was charged overnight.
Start-up, taxi out, t/o…..all previous flights had been normal, until the incident, not a single glitch. We were, having received simultaneous t/o clearance from Marvin, doing a follow-me routine with Barry Hou/Dirk Flejter.
Subsequently checked elevator servos (JR DS 8711s) both are normal. In any case it is not conceivable that both would fail simultaneously to cause an immediate straight down attitude without a single wiggle from any transmitter signal.
The RX batteries were a pair of AGA LIFE 6.6 V 3000ma installed new, along with the new receiver, with 20 some flights. It’s not conceivable that both would have failed simultaneously with a minute+ left in a 6 minute flight.

I am very concerned with what system I should use for my fleet so would appreciate some professional input before proceeding any further.

bluescoobydoo

I have always used futaba without a single problem why not give them a try?

tp777fo

My Feedback: (28)

I had been using DMSX with a JR12X for many years. I started to think the TX was getting a little old and started looking for a new setup. I purchased a DX18 Stealth which had problems out of the box. The screen didn't work and required sending back to Horizon. When I got it back the gear switch fell out. Now I am getting worried. I started checking on RCU threads about Spektrum mystery crashes and started looking for another radio system. I felt pretty safe with the JR labeled systems but the Spektrum labeled items made my hair stand on end. I had no confidence in the quality of the Spektrum product and wound up purchasing a JR XG14. I had JR Americas to place a 2 position switch where the normal gear switch is instead of the spring switch as from the factory. For my FB Dolphin I put 2 731BX receivers working through a dual battery Xport Duo 14 port PWM converter with altitude and airspeed telemetry. One receiver is in the front of the airplane and the other in the rear. My other airplane is an Excalibur with a JR 11ch PWM receiver which is also dual battery. The JR Xbus is not difficult to set up and mated to both radio systems quite easily. I could tell a difference on the first flight as the XBus has immediate response. The range for the DMSS is much better as per another thread I read where a guy took all the major radio systems and did a comparison of range and rebinding. The JR was only beaten by Weatronics. Rebinding was instant once back in range...over 5000' The JR does not have the telemetry options that Spektrum does but I found the telemetry to be a bit of a pain in the rear. I have my XG 14 set up with a beeper for too fast and another for too high. I am extremely happy with my JR DMSS system. I am glad I made the switch.

Len Todd

I have never had a DSMX Powersafe Rxer "main unit" fail and I have lots of them. I have had a remote Rxer fail, but it did not result in loss of control as the other two were still working. However, I do use DSMX transmitters. Other than the one remote, I have never has a DSMX receiver fail and I have dozens of them.

One of our club's Jet Guys just last night called me about troubleshooting a 9 channel JR Rxer main unit that apparently failed. I'll probably hear more about that tonight.

I have seen a frame loss show up once when I was way out there with a Giant. I typically use fades to check the positioning of the Remotes within the airframe. I have a transmitter alarm set on frame loss. Get that alarm and it had better be heading back at me.

A remote failure will not result in a Rxer failure. A remote's cable connection will not result in RXer failure. Redundant batteries eliminates a switch failure or harness connection failure.

Have you tried a full power range check (i.e. plane ~1/2 mile downrange and see if the controls still work in normal transmit mode)

If the RXer failsafed at straight and level, how do you account for the last abrupt turn down?

You did not say how the Remote Rxer's antenna were oriented. 3+ Remotes should = 3+ different orientations.

Personally I would send the Rxer and transmitter back for testing.

Zeeb

My Feedback: (41)

I've never had any issues with my JR/Spektrum stuff until it came time I needed to upgrade my 12X and the only option at that time was the Spektrum DX-18. It's a great radio for the price but it always felt awkward to me with short fingers and some arthritis, it just didn't fit.

JR didn't have anything at the time to replace the 12X and since they were getting ready to split the sheets with Horizon/Spektrum, I knew I'd have to buy all new rx's one way or the other so I bought a Futaba 18MZ.

I left all my gassers and one turbine, most of which have 12 channel PowerSafe rx's, on my JR 12X. The Pattern planes and the new stuff from foamies to turbines has gone on the Futaba. It's been a really good radio even it the programming is initially some what intimidating. It's also $3000.00 unless you catch a Tower sale like right now where you can get one for, I think, $2500.00.

So what's the point of this discussion? The new Futaba 18SZ came out not too long ago, it's got about 95% of the functionality of the 18MZ for a about a 1/3rd the price. If you use the coupons and such, you can get one for under a $1000.00 and let me say, that is the closest to feel of my JR 12X of any of the newer radios that I've handled.

Everyone is singing the praises of the 28X which is almost as much money as the Futaba and it's had it's share of teeth cutting going on. At least with Futaba, it was a known quantity.

I have no idea what caused the issue with your A-10, but I wouldn't junk any radio stuff just yet. You may want to consider doing what I did to start changing over to another brand radio if that's what you choose.

David Gladwin

Simple solution. Bolt a Weatronics dual Tx module and dual receiver onto your 12x for an incredibly capable and secure radio system which also gives you the ability to analyse your entire system performance in great detail. I have been using just this combo on 2 12xs and a 10x for some years , 5, with perfect results on 14 receivers in all forms of models, jets, electric and sailplanes. Having all the downlinked data for system analysis is pure gold.

That said, my 28x is also performing perfectly on DMSS but I don't have the downloaded numerical data, as I do on Weatronic, to analyse just how well it really is performing.

David Gladwin

TTRotary

DMSS for the reasons below.

I have both as well as some leftover stuff on XPS. I have moved all my expensive airframes over to DMSS (XG11). It not only feels better in the air, but if you look at wavelength analysis and how DMSS uses the spectrum, it is as robust a FHSS protocol as I can imagine, starting with the capture bandwidth being 2.8MHz versus 1.1MHz for DSMX, the next most robust. The DMSS radios are so dominant on the spectrum that I wonder if it would pose a risk to weaker protocols like DSM at the field.

DSMX is also a solid protocol and is much improved over DSM, but DMSS is better. The other reason to go DMSS is the quality of the radios. The JR stuff is just better made and there have been few reported problems with JR radios against a lot of issues for Spektrum (even though the Spektrum stuff is supposedly made by JR).

The downside to DMSS is that is cannot be used with any of the DSM/DSMX stuff. I have a DSMX radio for my cheaper airframes (DX6).

Programming and function-wise, the XG radios are almost the same as a 12x, but menus are a bit more intuitive. Coming from a 12x, the XG interface will look instantly familiar.

DiscoWings

My Feedback: (76)

DSM, DSM2 and DSMX rx are no longer available from Horizon, only DMSS.

IFLYBVM2

My Feedback: (360)

OK my two cents worth: In my opinion, when you removed the 1221x and replaced it with the Spektrum, you did not 'upgrade'. The 1221x receivers were made in Japan and if you search the net' you will be hard pressed to find very many, if any, complaints about them. Not so with the Spektrum receivers; the negative comments are numerous. Lots of guys use them with no problems, but there are way too many instances of things happening like you described. In my opinion, and simply put, they do not have the reputation and reliability that the older JR receivers do.
When I finally do replace my 12x and 1221x receivers one day, it will be with the new JR DMSS stuff, which is getting really good reviews so far.

david surick

got to ask ? now with twin turbines and ecu can there be intefearace if they are close to each other ? this twin s seam to be a problem now call reps and ask is there a distance needed also twin rx distance also batt wires close to rx etc you got to ask and ask also jet cat both reps and kingteck one will say this one will say that myself I always get different inputs if its me I will have turbines running have two people know there running have one person get in there car drive to the end of runway use two cell phones keep in contact and run them up to 3/4 power check data taxi back check lines refuel change batts do again

jefflangton

My Feedback: (23)

Bolt this on, add a satellite, blah blah blah. Spek is crap. I dont feel sorry for anyone using it. Do your research. Yet people still use it, in jets no less. Its crap in black and white. I see 5-10 spek brownout total losses a year. Fasst all the way. NEVER, EVER A SINGLE GLITCH!!!!!

david surick

I have a dmss tx new with rx and x bus never used if you are interested cant find anyone to program it its hard for me if you like I can sell for 500

david surick

my email is [email protected]

david surick

also everyone make sure your sats are on when your switch is moved on slowly it can read slowly tx rx fast and wait for sat

Zeeb

My Feedback: (41)

Now there's one that'll be hard for the JR DMSS fanboys to swallow.... lol

rhklenke

My Feedback: (24)

That is absolutely not true. Horizon sells both the Spektrum DSMX receivers and the JR DMSS receivers.

That being said, the Spektrum DSMX RF link is way behind the times. All of the radio manufacturers in the market (even the HK off-brand ones) use an RF link that is more robust than DSMX. That, and given the problems that some have had with Spektrum hardware and software (above are a few examples) I'd go with JR DMSS over Spektrum DSMX 8 days a week...

Bob

Dave Wilshere

The thread asks one question!

Roger, DMSS. I've used it since 2011 and its been faultless, my very smart 'techy' people also chose it and say its the best system.
We tested it in the worst installations possible and it was amazing.

Dave

George

My Feedback: (57)

Roger,

If my only choices were DSMX or DMSS, it would be DMSS for many of the reason already stated.

Greg Wright

My Feedback: (6)

Roger,

I have 1000's of flights with my Spektrum radios, and have never had a single issue or loss of an airplane with any of them since day 1 when they first came out....

It just seem's that when someone loses a plane for some reason or other. The first thing that they blame is the radio and most of the time the blame should go towards the person holding that radio....

Until all of you HATERS can prove to me that it's always the radio's fault. Then that will be the day i might think about switching brands!!!

I'm just sick of always seeing and hearing about the branding wars that are in this hobby now days, it was never like this back in the day.
If you don't like a product then don't use it that's the bottom line.

We are all grown men in this hobby let's act that way or go away!!!


Have a Happy New Year Everybody!!!!!!

Chris Smith

My Feedback: (2)

Roger,
None of the Nashville Jet Band guys running DX-18s are having any issues that I have seen or heard of. And you know how much flying Scott and Randy do...

I believe only Glenn has moved to a JR 28X. But if I recall, he had always stayed JR.
Last I looked I'm the only Futaba guy out of our 10 or so jet guys.
If there is another Futaba dude added recently, I don't know of her.


What I'm saying is that either radio you are already using is up to the task. The Nashville Jet Band flies year round and A LOT! Keep the faith.
Cheers

Turbotronic

It does not really matter if you use DMS2 or DSMX or whatever. All the rx's have a fundamental design flaw.
DMSS uses superior RF chipsets ( same as weatronics btw ).
From a design POV all spek RX's are a crash waiting to happen. Sooner or later it will show itself. I have confirmed the design flaw with the vendor of the Cypress RF chipset. (Not their flaw, spek's flaw)

rgburrill

I have heard that "upgrading" from a JR to a Spektrum is a misnomer.

JeffH

My Feedback: (43)

What is the flaw and what sort of indications or symptoms does it cause? I use DMSS, but I would like to know about this due to the fact we have a club full of Spektrum users.

jetmaven

Faast

Zeeb

My Feedback: (41)

Which kind of oil is best.........