JohnVH

My Feedback: (38)

They are adjustable? I didnt know that!

They are very strong!

This field is very rought for a small tired plane from what I can tell, when it gets up to speed the aircraft starts to bounce. The nose wheel being spring loaded didnt help mine, I am going to check into adjusting it, that will help alot, mine is too soft! Where did you read that?

K1jets

My Feedback: (1)

I called TGA & talked to some guy (forgot his name), he said the struts come with the stiffest spring, but there is a softer one available. Also, he said they could probably do a "custom" set-up if you wanted. Their # is 815-433-6132.

If you can access the spring, then I'm sure you can change springs yourself. It may take a few tries, but I'm sure you can come up with a set-up that will work at your field. - That's what I plan on doing.

I won't be getting my struts for a couple weeks - I was told they have 20 sets being made now.

JohnVH

My Feedback: (38)

Yep

booker-RCU

My Feedback: (43)

Hey John,
I flew the Bobcat at Shelton today . It's a good thing you didn't come down as it rained so much I only got one flight in.
If you want to borrow my channel 57 950S receiver and transmitter module, to try and solve your rf problem let me know and I send them to you.
Galen

JohnVH

My Feedback: (38)

WELL, I was just jumping on for an update!!

A friend stopped by, (Goggles on here), and lent me his 10X and a 950rx on a different channel, mine is 52, his is 48 I think, well, I changed rx's, helped some but still not enough range, this was on channel 52 still, changed tx's, still no range. I changes crystals and the module, and now I get as far as I have room for here, I paced off 40 good paces, about 3' paces, and that was with it inside my garage, and I walked down the alley, I couldnt see it because there was a tavel trailer in the way!! I was going by sound, I just couldnt hear it anymore, am going to do a range check within the hour, it MAY be cured with a simple channel change!!! Man I hope so.
Be back in a few.

vortex00

My Feedback: (22)

John,
My TopCat is about the same point as yours. I'll be doing a range check tomorrow with a RAM750PR in it, Deans antenna, JR8103 tx, JR950 rec. Did the freq. scan with my ICOM IC-R2 tonight with the antenna next to the ECU, all was well. Surprising what's on the image freqs though. I'll be interested to see the comparison.

Jack

JohnVH

My Feedback: (38)

I would LOVE to see some pics of yours!!!!

rcs1313

JOHN,

What battery are you using for the receiver? Are you using a 5 cell 6 volt pack and if so with or with out a voltage regulator?

I had serious range problems with my 10x and 950s receiver using JR 1800ma 5 cell packs w/o a regulator. Going back to the standard 4 cell pack solved ALL my range problems. I plan on going to one of the large 1500 to 2000 ma 4 cell packs to eliminate the need for a regulator from now on.....

Just a thought---sounds dumb, but the JR systems seem not to like the higher non-regulated voltage on some of their receivers..

Rod

DavidR

My Feedback: (1)

I don't see what difference you would see between the 2 packs. I get excellent range with 5 Cell packs with and without regulators. I use the Jaccio 5.2 volt regulator. I have used these on the 950S, 940, and the new 955 I just can't see where it would make a difference.

David Reid

JohnVH

My Feedback: (38)

I am using two 4 cell 1800 packs in the nose.


I tried a third channel, 23, and get 150' with no antennae, through a travel trailer and around power wires with the jet out of site in my garage, When I get that new ECU Im going to try my channel 52 again and see if it makes a difference in range from my origional ECU.


Anyone else have channel 52 and a jetcat and it works?

rcs1313

Dave,

Some time ago this was thoroughly hashed over on the old RCO forums....

I learned very quickly that, in trying to convince individuals that there actually IS a problem with the JR 950 receivers and large 5 cell battery packs was a waste of my time.

I only know by my own personal experience, witnessed by many fellow fliers, that using 2 JR 10x TX ---4 different JR 950s receivers, 2 on ch52 and 2 on ch19---3 different JR 5 cell 1800 ma packs and the standard 4 cell pack that came with the new JR 10x, I had a major problem...all kinds of combinations were tried and the only thing that solved the problem was the reduction in voltage by going back to the 4 cell pack . I was not using a voltage regulator at the time.

Lee Demary has a great deal of information to share on this subject of overvoltage and RF interference caused by it----the problem is real, but it sure is hard to convince people to do the really long range radio checks.... oh well, at least I saved my plane......

I still feel that some of these "unexplained" radio failues and failsafe hits are caused by this very situation.

I do find it interesting that John is having trouble on ch 52....the same ch that I was on. My new JR 10x is Ch 52....hummmm.

Rod

DavidR

My Feedback: (1)

Rod,

I am not trying to argue about it but I guess I missed those threads. There are a whole bunch of RC'ers out there flying with 5 cell packs and your case is the first I have heard about it. It is obviously not John's propblem as he is running the 4 cell packs. I will say that unregulated a 5 cell pack can be as hot as 7.2 volts servos jitter, and that may be a potential source of noise but just an increase in voltage I just can't see it. But that is just my opinion, and experience. Every jet I own has a 5 cell pack and my range has always been excellent, both with the JetCats, and my old RAM's.

David Reid

Silver182

My Feedback: (2)

John,
I've got one of the Futaba 9zWCII fully synthesized transmitter / receiver combinations. It takes a few seconds to change freqs, and my new version 4(d) ECU works fine on channel 52 / 51 / 53 / 60 / 11 / 32 / 48. Those are the only channels I've checked. I just installed the new version 4(d) ECU in my MIG. The one big difference between my setup and yours is that in my MIG I am using the Futaba rather than the JR. Thats a long old story but suffice it to say the Futaba for some reason worked better with the older version 2 ECU.

If you could get your hands on a Icom R-2 scanner, program it for all frequencies, image & primary, do a scan of your ECU you might be able to find the "Cleanest Channels." That is what I used to go through to get a flyable range check. Go to Joel's Web site to find out how to program the R-2 and what freqs to program in for the image sets.

R-2 Web site
http://www.charlesriverrc.org/articl...r_icomicr2.htm

Better yet just relax until Bob can get you a different ECU, the one you have is just not up to the new Version 4 standard, somethings broke inside -----------

Again, don't forget the full throttle run-up while checking the Max range distance!!!
Lee H. DeMary
AMA 36099

JohnVH

My Feedback: (38)

Ill check one of those out.

Dont worry, Im going to do every check I can think of after all this!!!!!!!!!!!
But I cant believe how much of a difference there was is just changing channels! Pretty interesting!

Thanks

rcs1313

Well Dave,

Without knowing how you do your range checks or exactly what equipment you are using, its a moot point.

For example, ole Jackjet prefers to get up about a 1000 ft and put his antenna down to see how the plane responds. This may be OK, but would appear to me that it tells you nothing about what may happen on a long low approach close to the ground where the signal has degenerated.

I can remember my first Futaba manuals , 20 years ago, explaining the range was approximately 1 mile straight up in unrestricted air space and gradually degenerated to approx 700 yards on the ground.

Others have chimed in on this subject, some have experienced what I am talking about. Some have tried to explain the reason this can happen, especially the explanations from Silver182 (Lee DeMary). I very much appreciated his input.

Needless to say it made me gunshy , the solution is to use a voltage regulator to reduce the voltage to around the 5.2 mark or stay with 4 cell packs and eliminate just one more component in the system BUT, still do the extended range checks to see just what you really have for range on the ground.

There is nothing in the manuals about overvoltage. There is nothing in the manuals about extended range checks. There is nothing can be done to convince everyone to do long range -range ckecks the way Lee does, But there have been many "unexplained" failsafe failures, that I would bet a nickel to a dog turd, was caused by unregulated voltage on some of the systems.

Rod

jglp3-delete

My Feedback: (1)

I just did the radio/ground checks on my Bobcat today. I too have the new 4.0 ecu on a P120, JR 10x radio with a 955s receiver (ch 48), and the antenna is routed out in the left wing.
With ECU on and engine off, I'm getting well over 400' in all quadrants before it drops out. Plane is 3' off the ground and radio antenna removed. Remarkably, off the nose of the plane, I have over 900' of range!
There's basically no difference in range with the ecu on or off. Like others have stated here, I think it's probably your ECU. Good luck with it!

JohnVH

My Feedback: (38)

Is there anyone out there with a JR on channel 52 on a jetcat?? Like to wonder if I am the only one trying that channel on it?

Mluvara

My Feedback: (10)

Hi guys-

I don't quite have a turbine yet (working on the waiver), but have an interest in the RF/EMC stuff going on. I have a facility (10m semi-anechoic chamber) at work used to measure EMC/RF emissions. It seems like there has been problems with frequencies near 72MHz on many ECU's, and other R/C electronics. I can, if need be, measure the emissions off of some of these devices to a good degree of accuracy as our facility is used for compliance measurements to many countries and agencies. It seems with today's ever increasing electronics in our planes, the issue of interference in these models is becoming a day to day occurence.

John- not sure if you tried this, but move the antenna away from the battery leads. Having this in close proximity causes problems! Unattach the receiver from the mounts and raise it from the plane. I would move the receiver and or leads near the batteries away to see if range improves.

Michael

JohnVH

My Feedback: (38)

Already did that too, I had the rx sitting on top of the plane, the ECU on top as far away as possible on 6" extensions and the batt farther away from that!

Funny thing is, now on a different channel, I can just lay the whip ant. inside the fuse, on top of a servo, horizonatlly, and still get good range out of it :stupid:

Mluvara

My Feedback: (10)

Wow... This means it is some sort of "conducted emissions"- meaning it is coming down the ECU lines into the receiver on the same freq as your receiver and not a frequency being given off in close proximity. Adding a ferrite on the ECU lines would tell if this is indeed the problem. Most likely a harmonic of some frequency that equals channel 52.

Michael

Veritech

JohnVH,
I have been on vacation for the past 5 days and missed this thread. So anyway, here is my $.02 worh of information.

I have a Roo with a Ram 750 in it, now with over 25 flights on it. When I first set it up and did the first range checks I had a 5 cell 1400 Mah battery and a JR 8103 on CH 48 with a 649 Receiver. I was only able to get about 10 feet from the plane with the TX. antenna down, not removed. I was shocked. I removed the receiver antenna and placed it outside the Roo and still no difference. It did not matter if the ECU was pluged in or not. I took the receiver to D&M electronics to have them tune it. Dave from D@M said that the receiver and TX module were horribily out of tune. I had bought this receiver and module new from JR but they seem to have forgot to tune this one. I had Dave tune it but I was still only able to get about 35 feet away. So I bought another new 950 receiver, had D@M tune it, installed it, and was able to get 350 feet with the antenna down. I was very happy with this range and have been flying the Roo ever since with this setup.

On another note, I am not running a voltage regulator of any kind. Range seem to be the same with a fully charged pack just off charge as an almost dead pack at 4.9 volts. Go figure...

Just my experience,
Randy

JohnVH

My Feedback: (38)

Thanks,

I have tried 3 recievers, all with the same results, two 649's and one 950. I am running 4 cell batts. So far the only thing that has worked, was a channel change, which gave me enough range to fly, BUT, as soon as I get the new ECU, (wed I hope), I am going to try it all over again to see if that is the problem. Without my ECU plugged in I get TONS of range with no ant.

JohnVH

My Feedback: (38)

Well, got my new ECU today, a red V4.0, threw me for a curve at first, thought they were all blue.

ANYWAY


I put channel 52 back in and did a little check with the old ecu, cant get 30' without failsafe, I mean full failsafe!

I changed to channel 23, I get enough range to fly.

I put the new red ECU in place, put in channel 52, I get enough range to fly!!

I changed to channel 23, no change, still enough to fly, I am doing this in an alley behind my house, with power wires and a travel trailer in between me and the jet. BUT, there is definately 100% of an improvement on channel 52. Why does the old one work on channels 23 and 48??????????

Anyhow, I will be heading out to the field to give a correct check unobstructed to see what it says. And I have not done any engine running range checks either. But so far so good!

Thanks all for the help, and big thanks to Bob Wilcox of Jetcat USA for 2nd day airing me another ECU!!:thumbup:

mr_matt

My Feedback: (10)

Good luck on your flights.

I hope you are going to send the blue ecu back, we really want to take a look at it.

I rechecked a could of ECUs while this was going on, they are all dead quiet even on 52.

Good luck I am sure you will do fine with the test flights

JohnVH

My Feedback: (38)

Oh, I probably will be shortly, I would be VERY curious as to what the deal is, especially since its the second one I know of in the state that doesnt work on 52.

Im going to head out to the field to check it out for good.

Thanks