Serious range problem-->Here is the skinny now
07-03-2002, 08:02 PM
#2
Serious range problem-->Here is the skinny now
Went to the field for some range checks and taxi arounds, and while doing a range check, with the ECU unplugged I get over 200' with the antennae off on my 10X, all good here. So, next step is plug in ECU, now I get about 10-15' without the ant. with it on and all the way out I get maybe 100' max before failsafe. I moved the antennae into different places, even let it hang out of the fuse and set it on top of the fuse and all and no better, here is a couple pics, anyone have any tips or help or something that they see wrong here? I have seen other jets with the ECU and RX this close, what did I do wrong here?
FWIW, this is a Jetcat P80 with V4.0 ECU, JR10X and a 649PCM rx with a revolution ant.
Thanks much!!!!
FWIW, this is a Jetcat P80 with V4.0 ECU, JR10X and a 649PCM rx with a revolution ant.
Thanks much!!!!
07-03-2002, 08:04 PM
#3
Serious range problem-->Here is the skinny now
last.
On a better note, did taxi it around the field, Which I can see is way too rough for this machine, it was pretty windy, but coming into the wind, about 3/4 throttle I got a little 5' hop out of it! was not trying to but it did it in less than 100' of grass so the power is not going to be a problem, now if I can only beat this dang range problem!
Thanks in advance to all who can help me.
On a better note, did taxi it around the field, Which I can see is way too rough for this machine, it was pretty windy, but coming into the wind, about 3/4 throttle I got a little 5' hop out of it! was not trying to but it did it in less than 100' of grass so the power is not going to be a problem, now if I can only beat this dang range problem!
Thanks in advance to all who can help me.
07-03-2002, 08:15 PM
#4
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Serious range problem-->Here is the skinny now
From your pics, I noticed you are using whip antennae. What type is it, and did you cut the wire per instruction.
Do you have any dean's antennae? If not, can you get one a give it a trial?
How about moving the ECU temporally into the fuel compartment and see if you can get a better range.
Do you have any dean's antennae? If not, can you get one a give it a trial?
How about moving the ECU temporally into the fuel compartment and see if you can get a better range.
07-03-2002, 08:19 PM
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Serious range problem-->Here is the skinny now
Here are some basic EMC (Electromagnetic Compatibility) problem finding tips.
Try leaving the ECU powered, but disconnect the leads one at a time and do your
range tests.
I gather the range doesn't change with the engine running, so it's not likely the interference is coming from the fuel pump or glow outputs.
If it's the leads to the receiver, a ferrite choke may help. You said that the rx antenna position didn't change things much, so the noise may be conducted to the receiver via the control leads.
I can't see whether you've bundled any servo leads with the leads from the ECU, but that may also be a path.
Can you borrow another ECU, or try yours in another installation known to work?
Try leaving the ECU powered, but disconnect the leads one at a time and do your
range tests.
I gather the range doesn't change with the engine running, so it's not likely the interference is coming from the fuel pump or glow outputs.
If it's the leads to the receiver, a ferrite choke may help. You said that the rx antenna position didn't change things much, so the noise may be conducted to the receiver via the control leads.
I can't see whether you've bundled any servo leads with the leads from the ECU, but that may also be a path.
Can you borrow another ECU, or try yours in another installation known to work?
07-03-2002, 08:28 PM
#6
Serious range problem-->Here is the skinny now
Im the only turbine guy up here so I cant try it in anything else
running I seem to get same range
You mean unplug the leads to what? the rx?
The ant. is a new Revolution, everything is as the book, I have used them and deans before, like I said I get more than enough of range without the ECU powered up
I tried to keep everything seperate, the ECU leads to the turbine are all going down the opposite side of the fuse as the servo wires do except right under the turbine where they come out they are right with the servo extensions, thats the only place and only for a few inches.
Thanks guys.
running I seem to get same range
You mean unplug the leads to what? the rx?
The ant. is a new Revolution, everything is as the book, I have used them and deans before, like I said I get more than enough of range without the ECU powered up
I tried to keep everything seperate, the ECU leads to the turbine are all going down the opposite side of the fuse as the servo wires do except right under the turbine where they come out they are right with the servo extensions, thats the only place and only for a few inches.
Thanks guys.
07-03-2002, 08:44 PM
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Serious range problem-->Here is the skinny now
I see your neat, but neat doest't work in RF problems.
You should be able to get 1/2 mile range.
Move the turbine stuff behind the radio and keep about a 3" gap between batteries.
Darryl Usher
You should be able to get 1/2 mile range.
Move the turbine stuff behind the radio and keep about a 3" gap between batteries.
Darryl Usher
07-03-2002, 08:50 PM
#8
installation looks good
you should not run the TX and AUX connections next to the ECU.
Where is the data cable to the turbine running?
I do not know anything about that antenna you are using, are you sure it is hooked up right? Have you used an antenna like it before, with this same radio?
Where is the data cable to the turbine running?
I do not know anything about that antenna you are using, are you sure it is hooked up right? Have you used an antenna like it before, with this same radio?
07-03-2002, 09:21 PM
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Serious range problem-->Here is the skinny now
John,
I meant to unplug the leads from the ECU. The noise source is the ECU. The question is how does the noise get from the ECU to the receiver.
The noise could radiate directly from the ECU to the receiver, via the antenna. Or, it could travel via one of the ECU leads direct to the receiver (thr. and aux leads) or radiate from the leads to the antenna. The ECU power lead is also a potential suspect, but a bit harder to isolate as the cause. All you can do is try RF chokes in the leads near the ECU.
I have no doubt that RF suppression measures have been taken in the ECU to prevent this sort of thing. However the production testing may not include checking that the RF suppression is working, partcularly at 72 MHz.
I meant to unplug the leads from the ECU. The noise source is the ECU. The question is how does the noise get from the ECU to the receiver.
The noise could radiate directly from the ECU to the receiver, via the antenna. Or, it could travel via one of the ECU leads direct to the receiver (thr. and aux leads) or radiate from the leads to the antenna. The ECU power lead is also a potential suspect, but a bit harder to isolate as the cause. All you can do is try RF chokes in the leads near the ECU.
I have no doubt that RF suppression measures have been taken in the ECU to prevent this sort of thing. However the production testing may not include checking that the RF suppression is working, partcularly at 72 MHz.
07-03-2002, 09:30 PM
#10
Range Problem
John,
I had a similar problem with my P120 powered Roo. I flew mine with only about 20' of range with the antenna removed. I forgot you were supposed to check it with the antenna out. The flight went fine until I was on final and the RX went into failsafe. Luckily it wasn't hurt too bad.
I bought a crimper and the connectors so I could shorten the data cables. I also installed ferrite rings on all the leads that plugged into the ECU.
You might want to try a different RX, just for grins. Everything I did helped the range some, but the 2 things that helped the most were switching to the revolution whip antenna and switching from a JR 910 RX to a JR 945 RX .
Now with the P120 running I get a little over 1/2 a mile with antenna extended and 150+' antenna removed.
BTW ......Bob Wilcox and Matt were very helpful.
I had a similar problem with my P120 powered Roo. I flew mine with only about 20' of range with the antenna removed. I forgot you were supposed to check it with the antenna out. The flight went fine until I was on final and the RX went into failsafe. Luckily it wasn't hurt too bad.
I bought a crimper and the connectors so I could shorten the data cables. I also installed ferrite rings on all the leads that plugged into the ECU.
You might want to try a different RX, just for grins. Everything I did helped the range some, but the 2 things that helped the most were switching to the revolution whip antenna and switching from a JR 910 RX to a JR 945 RX .
Now with the P120 running I get a little over 1/2 a mile with antenna extended and 150+' antenna removed.
BTW ......Bob Wilcox and Matt were very helpful.
07-03-2002, 09:50 PM
#11
Serious range problem-->Here is the skinny now
Originally posted by Darryl Usher
I see your neat, but neat doest't work in RF problems.
You should be able to get 1/2 mile range.
Move the turbine stuff behind the radio and keep about a 3" gap between batteries.
Darryl Usher
I see your neat, but neat doest't work in RF problems.
You should be able to get 1/2 mile range.
Move the turbine stuff behind the radio and keep about a 3" gap between batteries.
Darryl Usher
07-03-2002, 09:51 PM
#12
Re: installation looks good
Originally posted by mr_matt
you should not run the TX and AUX connections next to the ECU.
Where is the data cable to the turbine running?
I do not know anything about that antenna you are using, are you sure it is hooked up right? Have you used an antenna like it before, with this same radio?
you should not run the TX and AUX connections next to the ECU.
Where is the data cable to the turbine running?
I do not know anything about that antenna you are using, are you sure it is hooked up right? Have you used an antenna like it before, with this same radio?
Data cable is running down the right side of the fuse with the other lines for the turbine.
I have used this type of antennae with this radio too, on another model.
07-03-2002, 10:17 PM
#14
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Serious range problem-->Here is the skinny now
One observation here too..
DO NOT EVER range check or operate your radio with the antenna off. Doing this overloads the RF deck and eventually will detune your radio. I know what it says in the manual, but trust me on this one.. If you need to do a range check.. just do it with the antenna collapsed.
Doug
DO NOT EVER range check or operate your radio with the antenna off. Doing this overloads the RF deck and eventually will detune your radio. I know what it says in the manual, but trust me on this one.. If you need to do a range check.. just do it with the antenna collapsed.
Doug
07-03-2002, 10:22 PM
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Serious range problem-->Here is the skinny now
John,
Try unplugging the data cable that goes to the I/O board from the ECU. When I was using the V 2.0 ECU in my Bobcat I could not get the kind of range I wanted with it plugged in. I unplugged it and got an acceptable range. Also like Matt said the throttle and aux leads from the ECU, and the solenoid leads, do not run them right beside the ECU get them as far away as possible. Put a seperation between the reciever and ECU battery packs as well. I know when I wnet to the V 4.0 ECu in the Bobcat my range improved by around 70'. Also what is that right in front of the ECU beside the I/O board? I can't tell from the pictures.
David Reid
Try unplugging the data cable that goes to the I/O board from the ECU. When I was using the V 2.0 ECU in my Bobcat I could not get the kind of range I wanted with it plugged in. I unplugged it and got an acceptable range. Also like Matt said the throttle and aux leads from the ECU, and the solenoid leads, do not run them right beside the ECU get them as far away as possible. Put a seperation between the reciever and ECU battery packs as well. I know when I wnet to the V 4.0 ECu in the Bobcat my range improved by around 70'. Also what is that right in front of the ECU beside the I/O board? I can't tell from the pictures.
David Reid
07-03-2002, 10:25 PM
#16
Antenna - on or off. That is the question.....
Have you seen the latest Horizon newsletter. I received mine yesterday.
A very good article on range checking, and I asume fully endorsed by Horizon and they specifically say for a 10X to remove the antenna.
They mention about the increased load on the RF output stage but also say that for short periods it is not a problem.
Any JR reps please comment.
Paul
A very good article on range checking, and I asume fully endorsed by Horizon and they specifically say for a 10X to remove the antenna.
They mention about the increased load on the RF output stage but also say that for short periods it is not a problem.
Any JR reps please comment.
Paul
07-03-2002, 10:33 PM
#17
Serious range problem-->Here is the skinny now
I was gonna say too, my 10x manual says I believe to range check with antennae off too. have to check though.
Made one observation so far, took the aux and throttle leads off the RX, I got much more range than I had! I am out of room here, which is maybe 30-50' tops, so I need to get it out into the open to see how much this has helped, BUT, it does not matter which one, aux or throttle, both will cut range alot, so how can I run it without these plugged in? I cut them lose from where they are zip tied to the ECU and just ran them straight across where the retract will go to check.
DavidR, There is the batt pack, behind that is the board, then ECU, there is nothing else there, I think it just looks like there is.
Thanks!
Made one observation so far, took the aux and throttle leads off the RX, I got much more range than I had! I am out of room here, which is maybe 30-50' tops, so I need to get it out into the open to see how much this has helped, BUT, it does not matter which one, aux or throttle, both will cut range alot, so how can I run it without these plugged in? I cut them lose from where they are zip tied to the ECU and just ran them straight across where the retract will go to check.
DavidR, There is the batt pack, behind that is the board, then ECU, there is nothing else there, I think it just looks like there is.
Thanks!
07-03-2002, 11:51 PM
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Serious range problem-->Here is the skinny now
OK John...
First if you unplug both your throttle and AUX leads from your receiver you will get better range, reason is because you have turned off the ecu! Jetcat ECU is activated by turning power on to the receiver.
I did notice when I "Made The Switch" that my range was shortened by 50' or so. I am using the same antenna and since your range is good with ecu off your problem is definitely ecu related. Ferrite rings on the Throttle and Aux will help a bit, move your data board as far away from the receiver as possible and make sure you have NO control leads running near the ECU or turbine cabling. Since you have tons of room in the TC I would also suggest you pack the ECU much further back in the plane, just velcro it somewhere in the rear and use some extension leads for your throttle and Aux channels. Give it a try, bet the problem is gone. Get 150' min ant down/off before flying!!
BTW, got the pics but not gonna work good. Email me your # and I'll call ya!
Todd
First if you unplug both your throttle and AUX leads from your receiver you will get better range, reason is because you have turned off the ecu! Jetcat ECU is activated by turning power on to the receiver.
I did notice when I "Made The Switch" that my range was shortened by 50' or so. I am using the same antenna and since your range is good with ecu off your problem is definitely ecu related. Ferrite rings on the Throttle and Aux will help a bit, move your data board as far away from the receiver as possible and make sure you have NO control leads running near the ECU or turbine cabling. Since you have tons of room in the TC I would also suggest you pack the ECU much further back in the plane, just velcro it somewhere in the rear and use some extension leads for your throttle and Aux channels. Give it a try, bet the problem is gone. Get 150' min ant down/off before flying!!
BTW, got the pics but not gonna work good. Email me your # and I'll call ya!
Todd
07-04-2002, 12:10 AM
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Serious range problem-->Here is the skinny now
The 10X is range-checked with the antenna off, that is the recommended procedure. Just don't leave the TX on for more then 5 or 10 minutes with the antenna off.
Seems like you have lots of good advice here, I really don't have anything to add. I have yet to have a range problem with any of my RAM's or the one JetCat V4.0 I have.
Seems like you have lots of good advice here, I really don't have anything to add. I have yet to have a range problem with any of my RAM's or the one JetCat V4.0 I have.
07-04-2002, 12:25 AM
#22
yeah its weird
because the V4 ecus are so quiet almost none of these things we are talking about makes any difference any more (although a good practice is always a good practice!)
I sure wish it was a normal antenna before going down this troubleshooting path, but I trust others that they know this antenna is good. It is the only thing unusual.
I would swap the RX with a different one with a normal antenna to try to rule it out.
I sure wish it was a normal antenna before going down this troubleshooting path, but I trust others that they know this antenna is good. It is the only thing unusual.
I would swap the RX with a different one with a normal antenna to try to rule it out.
07-04-2002, 12:37 AM
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Baseline Range ------------
Hello John,
1. Your baseline range is about 100 feet short, for starters that needs to be addressed. Yes, you should see 300 feet, no antenna and aircraft about 3 feet off of ground. In my opinion you can't get a reliable range check antenna on or off with the aircraft on the ground!
2. Do not route any wires over, across, under, the ECU.
3. Do the same range checking with another receiver and Frequency. A change in freq sometimes does the trick.
4. It is possible you have an issue with that particular ECU. My guess is, if you had a different ECU the problem would not be as serious.
5. To really know for sure about range you should do the Real Range check, full antenna -------
6. Has your Wip antenna been tuned to that receiver?
7. Very important, even when you get all of your problems sorta solved, do a full power range check!!! I have found a lot of RFI being emitted from the pump motor at full power. For the most part if the receiver antenna is at least 3 or 4 inches away from the pump you shouldn't have to much range loss. But do the full power range check, that is the worst case scenario for RFI. Before you blast off!!
8. Bottom line is you should get 240 feet antenna off----full power, and or 4 tenths a mile antenna fully extended full power --- if your range is less than these distances something is not right!
John what you are experiencing is very unusual with the new 4.0 ECU---my guess is something is not right in the ECU, sounds like an older ECU!! The fuel pump issue is all that remains for the most part with the Jet Cat RFI--------
Lee H. DeMary
AMA 36099
1. Your baseline range is about 100 feet short, for starters that needs to be addressed. Yes, you should see 300 feet, no antenna and aircraft about 3 feet off of ground. In my opinion you can't get a reliable range check antenna on or off with the aircraft on the ground!
2. Do not route any wires over, across, under, the ECU.
3. Do the same range checking with another receiver and Frequency. A change in freq sometimes does the trick.
4. It is possible you have an issue with that particular ECU. My guess is, if you had a different ECU the problem would not be as serious.
5. To really know for sure about range you should do the Real Range check, full antenna -------
6. Has your Wip antenna been tuned to that receiver?
7. Very important, even when you get all of your problems sorta solved, do a full power range check!!! I have found a lot of RFI being emitted from the pump motor at full power. For the most part if the receiver antenna is at least 3 or 4 inches away from the pump you shouldn't have to much range loss. But do the full power range check, that is the worst case scenario for RFI. Before you blast off!!
8. Bottom line is you should get 240 feet antenna off----full power, and or 4 tenths a mile antenna fully extended full power --- if your range is less than these distances something is not right!
John what you are experiencing is very unusual with the new 4.0 ECU---my guess is something is not right in the ECU, sounds like an older ECU!! The fuel pump issue is all that remains for the most part with the Jet Cat RFI--------
Lee H. DeMary
AMA 36099
07-04-2002, 02:37 AM
#24
Serious range problem-->Here is the skinny now
The ECU is an updated to 4.0 one, I dont know if its just reworked or what, but either way.
I get about 100 paces, approx 3' or so each, so I am right on that 300' for a antennae off range check.
tuned whip ant.??
Looks like Ill have to do some wire routing to see if that does any good, I hope the weather is nice enough tomorrow to do it!
Thanks
I get about 100 paces, approx 3' or so each, so I am right on that 300' for a antennae off range check.
tuned whip ant.??
Looks like Ill have to do some wire routing to see if that does any good, I hope the weather is nice enough tomorrow to do it!
Thanks
07-04-2002, 02:37 AM
#25
Re: The I/O Board
Originally posted by mr_matt
John I noticed your I/O board is very close to the ECU. Do you have a long data cable coiled up bettween the ECU and the I/O board?
John I noticed your I/O board is very close to the ECU. Do you have a long data cable coiled up bettween the ECU and the I/O board?