Turbine range checks
12-25-2001 | 07:40 PM
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From: Las Vegas NV.
Turbine range checks
Wondering what kind of numbers the turbine flyers are getting on range tests. Distance with ECU on and ECU off? No brand names of turbines used or recivers and such, just the distance. Thanks much
Andy
Andy
12-25-2001 | 11:20 PM
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From: Rosamond, CA
Turbine range checks
I get 75 to 80 paces with a JR 10X, antenna completely off the TX. With my stuff I have seen no difference between ECU active or not, nor have I seen a difference with the turbine running. This is off all four quadrants and has proven completely adequate for all my jet flying.
OK, Lee, your turn.
OK, Lee, your turn.
12-26-2001 | 06:54 AM
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From: Littleton,
CO
Generic range check distances
I get 75 to 80 paces with a JR 10X, antenna completely off the TX. With my stuff I have seen no difference between ECU active or not, nor have I seen a difference with the turbine running. This is off all four quadrants and has proven completely adequate for all my jet flying.
OK, Lee, your turn.
__________________
TonyF
Team RAM, BVM, JR
Only the Best Will Do
Hello Tony,
My guess is Tony has done his range checks with his aircraft sitting on the ground. 75 - 80 paces equates to about 225 to 240 feet. The only reason I like to do a range check with the aircraft about 2 or 3 feet off the ground is that there are ground effects which are unpredictable. There are surfaces that dramatically effect the range check distances when either the aircraft or the transmitter antenna's are placed close to those surfaces. An example would be steel reinforced concrete. I believe if Tony would have done his range check with his aircraft up off the ground 2 or 3 feet he would have gotten closer to a 300 ft baseline distance with his 10X.
I am still a firm believer in Fully extended transmitter antenna range checks because all of the specific variables of brand and type are eliminated. If we are being specific, like Tony is, quoting distances related to his JR 10X, we can assume some numbers, just be sure not to relate JR's numbers with brand X's.
The important thing is to do your range checks in a consistent manner, preferably over the same types of terrain. If your base line distances exceed 200 feet transmitter antenna down or removed, that distance equates to about .34 miles transmitter antenna fully extended. Assuming these minimum baseline distances, the total distance is not as important as the percentage of difference between your (clean) baseline distance and the (dirty) ECU on distance. Tony has indicated he sees very little if any difference ECU on or off and only mentions a slight effect with turbine fully operational. I can think of no person who has flight tested and proven these ratios any more than Tony.
The main thing that I encourage everyone to do is to actually check the difference between baseline (clean) and ECU on (dirty), because each and every equipment installation, brand of turbine, and radio produces different results. In my opinion if you see more than a 20% degradation in range fix what's causing the problem or risk loosing your aircraft someday to "Unknown causes."
To summarize:
1. Baseline (ECU unplugged) minimum antenna fully extended 3.35 miles or (1760 ft.) ideal .5 miles or (2640 ft).
2. Those Baseline distances equate to approx. 200 feet minimum or 300 feet ideal, for a JR 10X with the antenna removed. *If the radio your checking has a shorter Baseline range than the these distances, it needs to be sent in for repair!
3. Assuming those minimums, then you should not tolerate any more degradation of those distances with turbine running, than a maximum of 20%.
4. **Worst case scenario with turbine running accept no less than 160 feet solid RF link, all directions, aircraft sitting on the ground with a JR 10X.
(As it happens I have confirmed the above distances using the Futaba 9Z series transmitter, with the antenna fully collapsed (inside the case) the Futaba and the JR (removed) are about the same. The fully extended TX ant. distances apply and seem to work out in practice between these two types of radios. I have tested both these types).
5. The only way I can equate distances to all other brands of radios, (generic ) would be to accept no less than the above Baseline distances (antenna fully extended), and strive for distances that approach or exceed the ½ mile mark.
*Note assumes aircraft is 2-3 ft above the ground supported by an inert (wood or plastic) stand or table.
**Note that I have only quoted one distance where the aircraft is sitting on the ground, all others assume 2 -3 feet above the ground.
Lee H. DeMary
AMA 36099
OK, Lee, your turn.
__________________
TonyF
Team RAM, BVM, JR
Only the Best Will Do
Hello Tony,
My guess is Tony has done his range checks with his aircraft sitting on the ground. 75 - 80 paces equates to about 225 to 240 feet. The only reason I like to do a range check with the aircraft about 2 or 3 feet off the ground is that there are ground effects which are unpredictable. There are surfaces that dramatically effect the range check distances when either the aircraft or the transmitter antenna's are placed close to those surfaces. An example would be steel reinforced concrete. I believe if Tony would have done his range check with his aircraft up off the ground 2 or 3 feet he would have gotten closer to a 300 ft baseline distance with his 10X.
I am still a firm believer in Fully extended transmitter antenna range checks because all of the specific variables of brand and type are eliminated. If we are being specific, like Tony is, quoting distances related to his JR 10X, we can assume some numbers, just be sure not to relate JR's numbers with brand X's.
The important thing is to do your range checks in a consistent manner, preferably over the same types of terrain. If your base line distances exceed 200 feet transmitter antenna down or removed, that distance equates to about .34 miles transmitter antenna fully extended. Assuming these minimum baseline distances, the total distance is not as important as the percentage of difference between your (clean) baseline distance and the (dirty) ECU on distance. Tony has indicated he sees very little if any difference ECU on or off and only mentions a slight effect with turbine fully operational. I can think of no person who has flight tested and proven these ratios any more than Tony.
The main thing that I encourage everyone to do is to actually check the difference between baseline (clean) and ECU on (dirty), because each and every equipment installation, brand of turbine, and radio produces different results. In my opinion if you see more than a 20% degradation in range fix what's causing the problem or risk loosing your aircraft someday to "Unknown causes."
To summarize:
1. Baseline (ECU unplugged) minimum antenna fully extended 3.35 miles or (1760 ft.) ideal .5 miles or (2640 ft).
2. Those Baseline distances equate to approx. 200 feet minimum or 300 feet ideal, for a JR 10X with the antenna removed. *If the radio your checking has a shorter Baseline range than the these distances, it needs to be sent in for repair!
3. Assuming those minimums, then you should not tolerate any more degradation of those distances with turbine running, than a maximum of 20%.
4. **Worst case scenario with turbine running accept no less than 160 feet solid RF link, all directions, aircraft sitting on the ground with a JR 10X.
(As it happens I have confirmed the above distances using the Futaba 9Z series transmitter, with the antenna fully collapsed (inside the case) the Futaba and the JR (removed) are about the same. The fully extended TX ant. distances apply and seem to work out in practice between these two types of radios. I have tested both these types).
5. The only way I can equate distances to all other brands of radios, (generic ) would be to accept no less than the above Baseline distances (antenna fully extended), and strive for distances that approach or exceed the ½ mile mark.
*Note assumes aircraft is 2-3 ft above the ground supported by an inert (wood or plastic) stand or table.
**Note that I have only quoted one distance where the aircraft is sitting on the ground, all others assume 2 -3 feet above the ground.
Lee H. DeMary
AMA 36099
12-26-2001 | 02:25 PM
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From: Las Vegas NV.
Interesting.
Just wondering if there was a cut off distance. But it sounds like the main thing is the "clean" and "dirty" numbers. This is what i got. Aircraft faceing away from me and on the ground ( my worst angle) ECU off, antenna down (not removable)i got 390 feet before fail safe engaged. ECU on, antenna down, i got 315 feet. looks like im in the 20% bracket.
Thanks.
P.S. im still interested in other turbine flyers range numbers if anyone still wants to post them.
Andy
Thanks.
P.S. im still interested in other turbine flyers range numbers if anyone still wants to post them.
Andy
12-26-2001 | 05:31 PM
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From: Nicosia, , CYPRUS
Range Checks
Hi Guys,
One thing that puzzled me on one of my aircraft was that when checking my radio's range (Graupner MC24)-antenna off, ECU on, Turbine running, (ECU and pump more than a foot away from each other as well as the receiver)- one side checked O.K. at 300 feet, but when moving to another angle, I would get only 30 feet. No matter what I did, I'd still get the same results. Any ideas on what could be causing this?
Happy Holidays to all
Chris
One thing that puzzled me on one of my aircraft was that when checking my radio's range (Graupner MC24)-antenna off, ECU on, Turbine running, (ECU and pump more than a foot away from each other as well as the receiver)- one side checked O.K. at 300 feet, but when moving to another angle, I would get only 30 feet. No matter what I did, I'd still get the same results. Any ideas on what could be causing this?
Happy Holidays to all
Chris
12-26-2001 | 06:32 PM
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From: Littleton,
CO
Directional Dilemma
Hi Guys,
One thing that puzzled me on one of my aircraft was that when checking my radio's range (Graupner MC24)-antenna off, ECU on, Turbine running, (ECU and pump more than a foot away from each other as well as the receiver)- one side checked O.K. at 300 feet, but when moving to another angle, I would get only 30 feet. No matter what I did, I'd still get the same results. Any ideas on what could be causing this?
Happy Holidays to all
Chris
Hello Chris,
It’s nice to hear people are checking things out. From what I’ve learned some of these ECU’s emit RF that will devastate radio range. I have also found that when you have a “Bad” ECU, jux-a- position and distance the ECU is away from your receiver and or it’s antenna only helps at the margin. In some cases those changes will do no good at all. If you can picture an area of about 6 ft. X 6ft. X 6 ft. a cube if you will, that area can be filled with RFI/EMI strong enough to drastically reduce your radios range. Mind you this is not true of all ECU’s of even the same type of turbine. The only way to know for sure if your setup will work with no problems is to do the Range Check.
Chris, what you describe sounds almost like the ECU’s RFI/EMI is producing a directional barrier? I never have witnessed this quit so dramatic as you describe. Is you radio directionally sensitive when your ECU is unplugged? If so maybe a realignment is in order. You may want to try a WIP type of antenna, they are supposed to be less directionally sensitive. You might also try the isolation method of diagnosis's, where by you strip down your system and rebuild component by component with totally different ECU’s, ECU batteries, servos etc., etc. switching only one at a time, until you find a problem unit. The isolation method does assume a lot in that you have access to identical components to swap out. I hope others have some ideas that will help solve you dilemma also.
If in the end you still can’t solve this problem, there is one solution that I’m sure will work.
E-mail: [email protected] to learn more about the Rat Trap, an RF suppression system designed to solve ECU RFI/EMI permanently. The prototype kit is designed specifically for the Jet Cat P-80 and P-120 but should be adaptable to any brand of turbine.
Lee H. DeMary
AMA 36099
One thing that puzzled me on one of my aircraft was that when checking my radio's range (Graupner MC24)-antenna off, ECU on, Turbine running, (ECU and pump more than a foot away from each other as well as the receiver)- one side checked O.K. at 300 feet, but when moving to another angle, I would get only 30 feet. No matter what I did, I'd still get the same results. Any ideas on what could be causing this?
Happy Holidays to all
Chris
Hello Chris,
It’s nice to hear people are checking things out. From what I’ve learned some of these ECU’s emit RF that will devastate radio range. I have also found that when you have a “Bad” ECU, jux-a- position and distance the ECU is away from your receiver and or it’s antenna only helps at the margin. In some cases those changes will do no good at all. If you can picture an area of about 6 ft. X 6ft. X 6 ft. a cube if you will, that area can be filled with RFI/EMI strong enough to drastically reduce your radios range. Mind you this is not true of all ECU’s of even the same type of turbine. The only way to know for sure if your setup will work with no problems is to do the Range Check.
Chris, what you describe sounds almost like the ECU’s RFI/EMI is producing a directional barrier? I never have witnessed this quit so dramatic as you describe. Is you radio directionally sensitive when your ECU is unplugged? If so maybe a realignment is in order. You may want to try a WIP type of antenna, they are supposed to be less directionally sensitive. You might also try the isolation method of diagnosis's, where by you strip down your system and rebuild component by component with totally different ECU’s, ECU batteries, servos etc., etc. switching only one at a time, until you find a problem unit. The isolation method does assume a lot in that you have access to identical components to swap out. I hope others have some ideas that will help solve you dilemma also.
If in the end you still can’t solve this problem, there is one solution that I’m sure will work.
E-mail: [email protected] to learn more about the Rat Trap, an RF suppression system designed to solve ECU RFI/EMI permanently. The prototype kit is designed specifically for the Jet Cat P-80 and P-120 but should be adaptable to any brand of turbine.
Lee H. DeMary
AMA 36099
12-26-2001 | 07:00 PM
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From: Nicosia, , CYPRUS
RF Suppression
Lee,
Thanks for replying this fast. The first time I had this problem, was with a BMT80. Then I moved the ECU and pump away from the Receiver and everything checked O.K.
FYI, I'm using whip antennas by Liebetrau on all my aircraft. When I installed my Simjet 1700, it happened again the same way, with still the ECU and pump away from the receiver. When ECU is off, the range is more than 300Ft in all directions.
At the time this happened, I had the help of Dave Bowen from RCJI and we tried everything, from earthing the engine, to moving the ECU really away from the receiver, or changing its position in the airplane. Funny, as it may sound, the engine was moved to another airplane and I never had the same problem again..........very strange!
Thanks for the info on the Rat Trap. I read your post on the Kidsource list. I think I'll buy it anyway, you never know, the bug might come back one day...
Regards,
Chris
Thanks for replying this fast. The first time I had this problem, was with a BMT80. Then I moved the ECU and pump away from the Receiver and everything checked O.K.
FYI, I'm using whip antennas by Liebetrau on all my aircraft. When I installed my Simjet 1700, it happened again the same way, with still the ECU and pump away from the receiver. When ECU is off, the range is more than 300Ft in all directions.
At the time this happened, I had the help of Dave Bowen from RCJI and we tried everything, from earthing the engine, to moving the ECU really away from the receiver, or changing its position in the airplane. Funny, as it may sound, the engine was moved to another airplane and I never had the same problem again..........very strange!
Thanks for the info on the Rat Trap. I read your post on the Kidsource list. I think I'll buy it anyway, you never know, the bug might come back one day...
Regards,
Chris
