Sean..... Baseline range check distance is established with all turbine / extra on-board equipment unplugged. Nothing being checked but the radio alone. 12 steps can't be!!!!!! You should be able to walk your with transmitter.... (antenna removed)... about 300 feet away from your airplane and still have normal control of all radio channels. 225 feet minimum...... if you can't get 225 feet away doing just the Baseline check you first need to send the transmitter module and receiver in for tuning!!

If you can't establish a baseline you'll never be able to have any distances to compare with i.e. "Baseline"

Remember all range checks should be done with your airplane mounted 3 feet up off the ground on a wood or plastic holder. Also at the 300 ft range you should be able to turn the transmitter in all directions and be "hold" or fail-safe free. Best thing to do is set the Elev. to full up fail-safe so you know exactly when you are seeing the limits of your range.
Lee

Given the problems you are seeing I would back up one more step. Pull the reciever out of the model, put it on a table, plug a 4 cell nicad into it, one servo and see what kind of range that gives you.

Steven

Sean

Forgive this if it doesn't apply but are you range checking the Isobar outside or while it's in the garage?

I'm not familiar with innEddies Isobar is there Carbon Fiber in the fuselage?

Ian

Well, what happened?
Scott

Scott, I'm actually 100% blown away and so pissed I don't know what to do. I bought another JR 10x brand new with a new module on a different channel. I bought a new 955 receiver.

I installed a whole new jet (Eurofighter), just finished it last night. Put all the new stuff in the airplane and same damn problem with all new stuff. I have never had a range issue on any airplane, and now I have two jets both with massive range failures.

Take the equipment out of the airplane, place teh receiver on a table with one servo in it no problem. Walk the receiver near the airplane and all kinds of jitters.

At this point, the only thing I'm willing to do is take the two jets to Austin and just ask people for their opinion on what to do. Because I'm clueless.

I have a Jetcat Titan and two Merlins, the only thing I have not done is install the titan into one of the airplanes because that's the only thing that is different from previous jets I've built. That being said, I can't say it has anything to do with the merlin because when I take the engine, ecu, and associated solenoids, propane etc out of the airplanes, I'm failing range still!

This is with receiver ant. outside the airplane and just taped to the side in differnet locations. So now I've tried two JR 10x's, and four different receivers, three channels and 1 JR 8103 radio digital trim aircraft version.

I'll be bringing everything I have to Austin Jet meet and anyone willing to help me figure this out, I WOULD GREATLY APPRECIATE IT!

Ian, there is approximately 12 square inches or so of carbon fiber in the isobar, and a bit more in the Eurofighter. These are the first airplanes I've built with Carbon Fiber in them, but routing the ant. anywhere even straight forward, or simply moving a receiver towards the oustide of the airplane causes jitters.

I don't think it has to do with carbon fiber, but who knows. I know other Isobars have flown no issues with more CF than I have in mine, I know other Eurofighters have flown with Merlin's in them. So I don't think it can be that. I kind of feel like it is something I am doing wrong, but I've built somewhere towards 7 seven turbine jets now and never had one glitch. So I'm just stumped.

I'm gonna try a revolution ant. tonight. At this point, I can't imagine it will make a difference, but can't hurt anything.

OK then, are you ready to try my suggestion (you know, the first one that I can't repeat here)? Or have you at least tried the vertical wooden dowel yet?

Sean, are you using any type of new "gizmo" or equipment that you haven't used before? Did you pull the equipment out of the Bar and stick it in the Euro or is it two separate sets of equipment giving you the same problem? If it's the Bar equipment just swapped to the Euro and you have the same issues, it's got to be some peice of the package and you need to figure out which component is the culprit.

BTW, I just maidened my Euro with the Merlin. My range check was good engine off and engine running with only about a 10% degradation but the overall range was less than what I have had in the past, but still plenty and more than my least range finding a few years back.

Hope you get it figured out, I'm sure you will.

Talk to you soon,
George

Wocket, give me a link to your package, I'm willing to buy one at this point just to have it in my arsenal. Yes, I had a big box in my garage and I just taped it straight up and to the box. No change.

George, totally new equipment in the Euro. Also tried swapping etc. In disgust tonight I pulled practically everything out of the Isobar and just started doing body work towards getting it ready to paint. When I rebuild it after it's painted I'll do the install one piece at a time. Also, I'll do a range check with one servo in the isobar and no other equipment to see as I'm adding things to the jet what triggers it. I've got about two weeks and two days to Austin, so I've been wet sanding tonight like a mad man.

Oh, NO NEW GIZMO other than the Merlin. Interesting though that you are seeing a measureable degradation with that engine though. I wish I could say it has to do with that "Merlin Whine" that is one wierd sound isn't it? That being said, after running the Merlin around 5 or 6 times thus far, the throttle response is very fast and the temps and thrust are AMAZING.

Well, even those I saw a difference, I attribute that to the airframe and not the Merlin. This palne has carbon fiber everywhere, more than any other plane I've had and the range is still better than my least acceptable range in an old Hot Spot I used to have. I wish we were closer, so I could come over and help.

Let us know the final disposition.

George

[quote]ORIGINAL: seanreit


I have never had a range issue on any airplane, and now I have two jets both with massive range failures.



I don't know what your problem is, but I sure know how it feels. I had the same maddening problem on a couple jets using a Futaba 8U, Futaba RX and long wire antenna. The only thing that fixed it was a Deans antenna, Futaba 9C and PCM Rx. Costly but effective. I needed a new Tx anyway..........

I'm with the other guys here. Try the Revolution and see what it does.

Cheers,

Tim

Sean

Just wondering does the Merlin ECU give u a fail safe hit count or you just seeing the Jitters?

Are there any Fluorescent lights on were u doing this test?

Sounds nut's but I built a 1/3 scale Mustang and had problems do to the Fluorescent lights in the garage.

Let me know if that Revolution works.

Ian

Sean,
Are you doing all these range checks in the garage or getting the aircraft outside to perform these tests????
Thinking about this one a bit


Oh, BTW.... The Merlin ECU, FADEC by Gaspar is one of the quitest ECU's on the market when it comes to EMI. Extensive test where run to check the EMI emissionsof the FADEC controller, results can be seen here: http://www.espiell.com/emi.htm

So.... Where are these tests being done? Is the aircraft on some sort of metal stand??? give me a bit more info as to how the test is being done in terms of aircraft location.

Todd, the plane is off the ground on a PVC stand shown in the isobar build thread at least 3 and a half feet off the ground. Very heavy duty stand.

To my knowledge, the Fadec does not count failsafes, to me it does not matter as I have different control surfaces deflect to max position so I can SEE WHEN it goes into failsafe. And it happens a lot. I have 12 foot ceilings with two flourescent lights up there. They are way to far away to give me trouble, but I started the tests outside and then moved the airplane inside, there is no measurable difference inside or out (in fact I discovered the problem at my local field outside 10 days ago).

I'm pretty convinced this has nothing to do with the fadec or merlin since when I take the engine out of the airplane and all associated stuff, I get the same problem! I didn't get around to installing the revolution last night, I got sidetracked and just started doing body work on the isobar to get it ready for paint.

The Euro is sitting in my office on the floor waiting for me to get back on the range issue. Probably hit it on Thursday night in anticipation of flying it this weekend.

Hey Sean,

Post a couple of pics of your radio, battery and ecu equipment setup. It would be helpful to see how you have everything situated and how your wires are run. It'll give us who are trying to help with a visual idea of what you may be dealing with.


Cheers,

Tim Schuy

Tim, I'll do that in a couple of days. Not a bad idea.

Sorry if someone already said this.

I suppose since you got your same results at your home as you did at the field, you are ruling out any local effects such as broadband interfernence at the test location, some Ham could have a new widget he just built that is off or a utiltiy is testing BPL or something like that..

Anyway, I think you really need to baseline the link performance, meaning test just the transmitter, receiver, rx battery (no switch) and one servo. I usually mount a 3 foot balsa stick to the servo output arm so I can see it, and mount this servo, RX and battery on a table or wooden sawhorse or something.

With JR 10Xs, antenna off, I have seen this test yield hundreds of feet of range. Anyway, make sure you get good results, and keep changing parts till you do.


Now you have a baseline distance to work with. Now start adding equipment one piece at a time (servos, switches, regulators, batteries ECUs, etc) and make sure you do not get a significant reduction in range (say less than 10%) as you add each part.

I concur with Todd. The FADECs I have used with the TJT engines have all been very RF quiet.

Problem solved. Ordered another 955 receiver and it came in today overnight delivery. This one "pretuned"?? With my chanel crystal already in it from Don's. I walked 75 paces without a failsafe and just sat there in Awe. I'm ordering another one tomorrow and will send the other one back to Horizon and ask them if they can figure it out.

Totally weird, but at least I'm back in the game.

I just ordered a 955S receiver and module for my 10SXII that will go in my BVM F-16 so it will be interesting to see what happens. Were you using the same crystal for all checks before the new receiver and crystal that fixed it were installed?

Chris

Sean

Glad you solved ur problem dude

Ian

Sean not so quick, now that your getting a decent Baseline range check (75 paces)... I say decent because you should be getting 100 paces you've got something to start with... Next thing to do in my opinion is put this 955 receiver through three other basic tests...... all of my receivers must past these three tests plus the Baseline range check to go airborne. And that's in a Baseline airplane....remember the turbine environment will reduce your range from Baseline!
1. Vibration check
2. Temperature check (put the receiver in a baggy in the freezer overnight)
3. Swamp check must pass the 1 & 10 ratio

Just because it's new doesn't mean it's any good, JR, Futaba, Airtronics, etc., etc. Swapping crystals never a good idea.... match tuning is the only way, other than luck to get a receiver that will pass all preflight tests with flying colors. I notice JR is now coming out with synthesized receiver / Transmitter modules. Don't anyone assume all channels will be the same! I have found that checking each of the channels just like it's a new and different receiver is a wise thing to do before flying! Yep, I did range checks at Superman one year Because I changed channels three times before finding a channel not being used by anyone else!
Lee H. DeMary
AMA 36099