Signal delay Question

[cloudshaker]

Hey Guys, I am experiencing a delay on my throttle at distance. I am running a JR PCM receiver, a Smart Fly power expander ,and hitec servos. I noticed when I am on the backside of the pattern (further away) there is a slight delay in when I throttle the engine and when it actually throttles up. In other words I can perform a fast throttle up and down, have the transmitter stick at idle position and then hear the engine throttle up and down while I am not moving the stick. Has anybody had the same problem or know the solution ? Thanks for any help.

[OverTemp]

Deleted by Poster.

[JustPlaneCrazy]

	Quote: Originally Posted by cloudshaker
	Hey Guys, I am experiencing a delay on my throttle at distance. I am running a JR PCM receiver, a Smart Fly power expander ,and hitec servos. I noticed when I am on the backside of the pattern (further away) there is a slight delay in when I throttle the engine and when it actually throttles up. In other words I can perform a fast throttle up and down, have the transmitter stick at idle position and then hear the engine throttle up and down while I am not moving the stick. Has anybody had the same problem or know the solution ? Thanks for any help.

If possible range check with a PPM receiver and see if you are getting bad interference.

My YAK did the same thing with the PCM then I put a PPM receiver in it and discovered I was getting very bad interference, turned out ZDZ had the Non-Resistor plug in the engine, the PCM masked out the interference pretty well but I was getting the throttle delay problem.

Like an idiot I flew the maiden in this condition before I realized what was happening, the maiden still turned out ok but it was a very interesting flight.

[cloudshaker]

	Quote: Originally Posted by OverTemp
	I have a suggestion... call whatever divinity you believe in and ask him to change the laws of physics! Here's a little math for you: The speed of sound changes with temperature, but lets assume 700 mph (it's in the rough ballpark). With this speed, if your model is 1/2 SM away (SM = Statute Mile), you will hear the motor 2.57 seconds after you throttle up. If you are 1320' away (1/4 SM) you'll hear the motor 1.29 seconds after you throttle up. Luckily it only takes your TX signal .0000026 seconds to travel the 1/2 mile to your model at the speed of light... otherwise flying would be interesting!!! Don't worry about your "problem"... every plane does it... you probably just never noticed until now. If you are flying a newer larger plane the "problem" is likely more significant since you are probably flying farther away than you were before... longer delay for the sound to reach you. Cheers

I understand the physics of sound somewhat, but as I posted there is a DEFINITE delay in my signal response. I have 10 aircraft, some PPM, some PCM. I have flown at this field for 5 years so I am pretty used to hearing the difference in sound between all of them. The problem I am experiencing is a response issue not sound, physics or my hearing. Thanks for the Physics lesson but no help. Do you have any other suggestions other than the laws of physics ? I completed high school 31 years ago, and am continuing my R/C training.

[cloudshaker]

Thanks Just Plane Crazy;
I have not tried a PPM receiver in this plane. makes sense. I will do that and let you know what happens. I don't know what plug type 3W is using but I will check that as well.

[JustPlaneCrazy]

	Quote: Originally Posted by cloudshaker
	Thanks Just Plane Crazy; I have not tried a PPM receiver in this plane. makes sense. I will do that and let you know what happens. I don't know what plug type 3W is using but I will check that as well.

If the plug number has the letter "R" in it somewhere it will be the resistor type and will be ok.

[OverTemp]

Deleted by Poster.

[cloudshaker]

Thanks OverTemp,
Makes sense I'm back on it this weekend. The stall test should reveal the response immediatly. This is my first 35% so I will admit you may have a point especially if you experience the same thing. The motor is a 3W 106 so it should show quickly. I intend to take JustPlaneCrazy, and your advice and check it out thoroughly. Thanks for your help and advice

[notorious_benny]

It will be the sound taking its time to carry to you mate. You even said that you can hear the difference.............

I only get it flying my big plane (DA 100 powered Yak). All my little stuff thats flown in closer you dont notice the time the sound takes to travel to you.

With large 35% models you would be suprised at just how far away they can get from you and how quickly they do it. I can almost gurantee you that its the delay for the sound to reach your ears.

[notorious_benny]

	Quote: Originally Posted by cloudshaker
	I will admit you may have a point especially if you experience the same thing.

Everyone experiences it, it used to unerve me a little when I first started flying my big (100 cc) plane. Now I am used to it. If your way up the end of the box you could be waiting 1.5 to 2 seconds for the sound to reach your ears.

[dirtybird]

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