9303 2.4 Data logging
09-08-2007, 06:11 PM
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9303 2.4 Data logging
Danny, or Paul,
Below is a copy of a post I made to another site where we are discussing the new X9303 in giant scale planes. It includes my latest day of testing. We have gathered some data and are really not sure how to interpet it. We want to be sure our intallation is safe and working properly. Your insight on the data would be most appreciated.
-STEVE-
Below is a copy of a post I made to another site where we are discussing the new X9303 in giant scale planes. It includes my latest day of testing. We have gathered some data and are really not sure how to interpet it. We want to be sure our intallation is safe and working properly. Your insight on the data would be most appreciated.
Here is the report from today's testing, I am afraid this will get a little long, so please bare with me. We are still flying the 40% Carden Extra, because it is all wood, and we are reluctant to install in the ZN-Line Composite plane as this is a more difficult environment for 2.4. Today we had the additional remote RX bringing the total to 4 receivers. So the current setup is:
40% Carden Extra (all wood) This plane has years of flights on 72 MHZ with no issues
DA-150
30 X 10 Carbon Fiber prop
16 JR 8611 Servos with Match boxes
1 Fromeco 2400 for ignition
2 Fromeco 4800 for RX
3 HD switches
1 Smart-Fly Reg on ignition
2 Smart-Fly Regs on RX
All batteries, Regs, and switches have 16 gauge wires and Deans connectors for good power supply
Smart-Fly Power Expander Sport
R921 2.4 RX with 2 remote receivers
Spektrum Data Logger
The main RX is installed on a raised platform that was built to get the RX up high in the fuse and away from the fuel, tank, motor, wires and other things that might interfere with it. It sits in the normal spot on the power expander, which is mounted on the left side of the plane. The first satellite RX is mounted on the opposite side of the plane, and orientated 90 degrees to the main RX. The second satellite RX is mounted about 1/2 way between the canopy and tail. It is up high in the turtle deck, and orientated so that it is different from the other two RXs. We could see no way that all 4 RXs in three locations could be shadowed from the TX simultaneously.
For those who have never used the Spektrum Data Logger, it logs fades at each RX location, dropped frames, and holds. Here is how the data is referenced by the logger.
A = RX-1 in the main RX body
B = RX-2 in the Main RX body
L = Left remote RX
R = Right remote RX
F = Dropped frames
H = holds
After yesterday's good test we were very interested to get actual numbers from the data logger. We did a range test again, which looked good, and took off. A flight of about 14 minutes, including the IMAC Unlimited sequence was flown. Here is the data from the logger:
A = 255
B = 740
L = 509
R = 520
F = 304
H = 1
We were not sure what to expect, but still, we were not impressed with what these numbers were telling us. There are a lot of fades on all RX's, over 300 dropped frames, and 1 hold. It looked to us like we were on the ragged edge of losing the plane, so we decided not to fly any more until we figured out what these number actually indicate about the robustness of the system, and our installation. We realized that we had not re-set the RX between the range test (with the power reducing button pressed), and the flight. It seemed reasonable that there would be fades, dropped frames, and even a hold with the low TX power. So we decided to do more tests.
First we re-set the RX and did our range test again, exactly as before. Here is the data from that:
A = 255
B = 279
L = 275
R = 191
F = 310
H = 5 (much more here this time)
It seemed to us that this could account for almost all of the scary numbers from the first test. We reset the RX and walked the exact range test line again without the range test button pushed so we had full TX power. This time all data values were 0. Very encouraging!
We decided to fly a short 4 minute flight and check the data again. Here are the results:
A= 88
B= 109
L= 96
R= 184
F= 4
H= 0
It still looked like a lot of fades, but because there were so few dropped frames and no holds, we thought it looked like at no time were all RXs blocked at the same time. So we re-set the RX once again, and flew a full 14 minute flight, which included the IMAC Unlimited Sequence once again. Here are the results:
A= 255
B= 796
L= 829
R= 894
F= 132
H= 0
Unexpectedly, the fades were even worse than the first test. There were still a lot of dropped frames, but this time no Holds.
Because we really don't know what kind of numbers indicate a properly working system, we decided in the interest of caution, not to fly with this setup again, until we fully understand what is going on. Now the search begins for information that will allow us to properly interpret this data. We are not giving up on the system, it flew nice. However think about it, without seeing the data from the logger, the range check seemed to go well, and the plane flies great. If this data does indicate that the system is not properly optimized by our installation, we could have very easily lost the plane. There are many out there flying 2.4 without doing this kind of system testing. What are the ramifications of this? Surely, at the very least, people are losing planes unnecessarily. I guess we will know more as our understanding of the system grows.
I would really appreciate comments from anyone with real insight to this data. In the mean time, I am going to forward this report on to JR for their comments. I'll let you know what I learn.
40% Carden Extra (all wood) This plane has years of flights on 72 MHZ with no issues
DA-150
30 X 10 Carbon Fiber prop
16 JR 8611 Servos with Match boxes
1 Fromeco 2400 for ignition
2 Fromeco 4800 for RX
3 HD switches
1 Smart-Fly Reg on ignition
2 Smart-Fly Regs on RX
All batteries, Regs, and switches have 16 gauge wires and Deans connectors for good power supply
Smart-Fly Power Expander Sport
R921 2.4 RX with 2 remote receivers
Spektrum Data Logger
The main RX is installed on a raised platform that was built to get the RX up high in the fuse and away from the fuel, tank, motor, wires and other things that might interfere with it. It sits in the normal spot on the power expander, which is mounted on the left side of the plane. The first satellite RX is mounted on the opposite side of the plane, and orientated 90 degrees to the main RX. The second satellite RX is mounted about 1/2 way between the canopy and tail. It is up high in the turtle deck, and orientated so that it is different from the other two RXs. We could see no way that all 4 RXs in three locations could be shadowed from the TX simultaneously.
For those who have never used the Spektrum Data Logger, it logs fades at each RX location, dropped frames, and holds. Here is how the data is referenced by the logger.
A = RX-1 in the main RX body
B = RX-2 in the Main RX body
L = Left remote RX
R = Right remote RX
F = Dropped frames
H = holds
After yesterday's good test we were very interested to get actual numbers from the data logger. We did a range test again, which looked good, and took off. A flight of about 14 minutes, including the IMAC Unlimited sequence was flown. Here is the data from the logger:
A = 255
B = 740
L = 509
R = 520
F = 304
H = 1
We were not sure what to expect, but still, we were not impressed with what these numbers were telling us. There are a lot of fades on all RX's, over 300 dropped frames, and 1 hold. It looked to us like we were on the ragged edge of losing the plane, so we decided not to fly any more until we figured out what these number actually indicate about the robustness of the system, and our installation. We realized that we had not re-set the RX between the range test (with the power reducing button pressed), and the flight. It seemed reasonable that there would be fades, dropped frames, and even a hold with the low TX power. So we decided to do more tests.
First we re-set the RX and did our range test again, exactly as before. Here is the data from that:
A = 255
B = 279
L = 275
R = 191
F = 310
H = 5 (much more here this time)
It seemed to us that this could account for almost all of the scary numbers from the first test. We reset the RX and walked the exact range test line again without the range test button pushed so we had full TX power. This time all data values were 0. Very encouraging!
We decided to fly a short 4 minute flight and check the data again. Here are the results:
A= 88
B= 109
L= 96
R= 184
F= 4
H= 0
It still looked like a lot of fades, but because there were so few dropped frames and no holds, we thought it looked like at no time were all RXs blocked at the same time. So we re-set the RX once again, and flew a full 14 minute flight, which included the IMAC Unlimited Sequence once again. Here are the results:
A= 255
B= 796
L= 829
R= 894
F= 132
H= 0
Unexpectedly, the fades were even worse than the first test. There were still a lot of dropped frames, but this time no Holds.
Because we really don't know what kind of numbers indicate a properly working system, we decided in the interest of caution, not to fly with this setup again, until we fully understand what is going on. Now the search begins for information that will allow us to properly interpret this data. We are not giving up on the system, it flew nice. However think about it, without seeing the data from the logger, the range check seemed to go well, and the plane flies great. If this data does indicate that the system is not properly optimized by our installation, we could have very easily lost the plane. There are many out there flying 2.4 without doing this kind of system testing. What are the ramifications of this? Surely, at the very least, people are losing planes unnecessarily. I guess we will know more as our understanding of the system grows.
I would really appreciate comments from anyone with real insight to this data. In the mean time, I am going to forward this report on to JR for their comments. I'll let you know what I learn.
09-09-2007, 12:55 AM
#2
Senior Member
RE: 9303 2.4 Data logging
Steve,
Having spent some time doing some testing with my data Logger and the Spektrum module in my 10X and 9303. Here is what I found.
Per the Manual for the Module system...not sure what the X9303 manual says as of yet. I don't have my X9303 yet because I don't have a pressing need at the moment. Its super hot here in AZ and I'm not flying a bunch now.
Per the Manual normal fades is 50-100 per a specific antenna
Any single antenna above 500 fades in a single flight you should move the antenna to a new position to get better clear signal.
45 continuous frame losses is a hold...
Now let us look at what is happening in a range check. I walk until it starts to drop out. So the 30 paces 90 ft distance in the manual is a minimum to the way I look at it. SO if you walk to the signal loss point using the Range check procedure outlined a couple years ago by John Adams and on the HH website...You will have lots of fades and even some holds. SO what I did was find the spot that was before the water fall in the range test. Re-set cycled power on the RX then walked to that point. Realizing this is probably worst case. Model on the ground....I then came back and checked the Data Logger....I then rotated the model 90 degs and did the same test over again.
Each time on the range test I was up near the 150-fade range...
Since it was below the "500" I test flew the model with a short 5-7min flight. I landed and found my Fades were near 50 on the main RX antennae and then both remotes I used were in the single digits for fades. This was best case flying a fairly close in flight and just checking things out. Being cautious. Similar to what you did.
I then flew normal 12-14min flight. I'm flying it in a 2M pattern model and flew sequences. Upon landing I'm getting less than 100 fades on the main ant(s) and rarely above 15-20 on the remotes. One flight I had 12 frames lost...Never had a hold. This a wood model but has a CF belly pan the covers the middle of the fuse where the main RX is located.
So my experience says that its good that you don't have any holds....but I would look at putting the RX's and remotes in a better location. If the Main RX is mounted on top of the Smart Fly expander the circuit board on this expander could be causing some blocking issues. Remember these ant(s) are really short so you need to plan the strategy of where to put them..... In my experience I change both the vertical and front to back location of each RX. You don't want them inline in any way...my opinion on this. So I have the main then I go up in the fuse and forward for the first remote, and down in the fuse and aft for the second remote.
I have found that The remote that is down the tail is almost always a clean and clear one with the least amount of fades.
Since you have a wood model... Perhaps cannisters or pipes are blocking when the model is flying at you. You could move one of the remotes very low in the fuse and aft....then the other further aft and high in the fuse....This might give you a better result. Think about changes in all 3 axis and get the biggest spread you can for max possible reception.
I can say this..with all those fades the frames lost is still pretty low. I think the manual says it should be around 20 frames...I had one flight that was up near 40 frames...but they were not the 45 continuous and obviously your were not continuous either or you would have had holds.
The Holds on the ground range testing are to be expected if you are trying to find the edge of the waterfall location.
This is a really cool tool to test the viability of your RX location choices. I love the way this thing works....Remember CF and metal parts are giving attenuation problems. Since the Ant(s) are so short due to the frequency...it makes sense that we need to re-think the way we mount things.
Try moving the main RX off the expander board and putting it next to it. I bet your fades on the main RX drop as a result....
Troy Newman
Team JR
Having spent some time doing some testing with my data Logger and the Spektrum module in my 10X and 9303. Here is what I found.
Per the Manual for the Module system...not sure what the X9303 manual says as of yet. I don't have my X9303 yet because I don't have a pressing need at the moment. Its super hot here in AZ and I'm not flying a bunch now.
Per the Manual normal fades is 50-100 per a specific antenna
Any single antenna above 500 fades in a single flight you should move the antenna to a new position to get better clear signal.
45 continuous frame losses is a hold...
Now let us look at what is happening in a range check. I walk until it starts to drop out. So the 30 paces 90 ft distance in the manual is a minimum to the way I look at it. SO if you walk to the signal loss point using the Range check procedure outlined a couple years ago by John Adams and on the HH website...You will have lots of fades and even some holds. SO what I did was find the spot that was before the water fall in the range test. Re-set cycled power on the RX then walked to that point. Realizing this is probably worst case. Model on the ground....I then came back and checked the Data Logger....I then rotated the model 90 degs and did the same test over again.
Each time on the range test I was up near the 150-fade range...
Since it was below the "500" I test flew the model with a short 5-7min flight. I landed and found my Fades were near 50 on the main RX antennae and then both remotes I used were in the single digits for fades. This was best case flying a fairly close in flight and just checking things out. Being cautious. Similar to what you did.
I then flew normal 12-14min flight. I'm flying it in a 2M pattern model and flew sequences. Upon landing I'm getting less than 100 fades on the main ant(s) and rarely above 15-20 on the remotes. One flight I had 12 frames lost...Never had a hold. This a wood model but has a CF belly pan the covers the middle of the fuse where the main RX is located.
So my experience says that its good that you don't have any holds....but I would look at putting the RX's and remotes in a better location. If the Main RX is mounted on top of the Smart Fly expander the circuit board on this expander could be causing some blocking issues. Remember these ant(s) are really short so you need to plan the strategy of where to put them..... In my experience I change both the vertical and front to back location of each RX. You don't want them inline in any way...my opinion on this. So I have the main then I go up in the fuse and forward for the first remote, and down in the fuse and aft for the second remote.
I have found that The remote that is down the tail is almost always a clean and clear one with the least amount of fades.
Since you have a wood model... Perhaps cannisters or pipes are blocking when the model is flying at you. You could move one of the remotes very low in the fuse and aft....then the other further aft and high in the fuse....This might give you a better result. Think about changes in all 3 axis and get the biggest spread you can for max possible reception.
I can say this..with all those fades the frames lost is still pretty low. I think the manual says it should be around 20 frames...I had one flight that was up near 40 frames...but they were not the 45 continuous and obviously your were not continuous either or you would have had holds.
The Holds on the ground range testing are to be expected if you are trying to find the edge of the waterfall location.
This is a really cool tool to test the viability of your RX location choices. I love the way this thing works....Remember CF and metal parts are giving attenuation problems. Since the Ant(s) are so short due to the frequency...it makes sense that we need to re-think the way we mount things.
Try moving the main RX off the expander board and putting it next to it. I bet your fades on the main RX drop as a result....
Troy Newman
Team JR
09-09-2007, 04:04 PM
#3
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Join Date: Jun 2006
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RE: 9303 2.4 Data logging
Troy,
Thanks for taking the time to write such a detailed post. It is very useful. We are repositioning the RXs and will keep moving things around until we get the system optimized. We should test fly again tomorrow. I will keep the thread updated as we learn more.
-STEVE-
Thanks for taking the time to write such a detailed post. It is very useful. We are repositioning the RXs and will keep moving things around until we get the system optimized. We should test fly again tomorrow. I will keep the thread updated as we learn more.
-STEVE-
