Steve Collins

My Feedback: (8)

Anyone out there know for sure whether 86 ft away is sufficient range? At 86 ft, one surface started a slight twitch/jitter. This distance was measured out in the middle of our flying field at least 250 feet away from buildings, fences, trees, cars, etc.

I can't find my manual to check what it says.

lynngordon

Aptar, quick answer is NO.

Here's the skinny direct from the Futaba FAQ's page:

Test one - engine/motor off, minimum of 100 ft. range

Have a friend view the model but not hold it, engine off.
Walk away from the model, holding the radio as if you were flying, and working all controls constantly. Stop when the servos jitter significantly (a jitter here and there is normal), control movement stops (PCM), or you lose control altogether.
Measure the distance. If greater than 100 feet, great! Proceed to test 2.
Less than 100 feet of range check means you need more information to determine if your system is safe to fly.

Test two - engine/motor on

Repeat the test with the model's engine running. If a decrease of more than 10% is noted from the "model held" version of test one, research and resolve the cause of interference prior to flying your model.
Check for significant vibration in the model, particularly loose engine or engine mount bolts.
If gasoline-powered, double-check all items listed above. Consider having the ignition, if any, tested.
Check that the receiver crystal is securely seated in the receiver.
Has the receiver been in even a minor crash? If so, fragile internal parts may be damaged and will not operate properly under the normal vibration/load of flight.
Be sure the receiver antenna has a proper strain relief and is not being pulled out of the receiver when the engine is running.
If you are unable to find the cause of the problem, DO NOT FLY. Send the receiver for service immediately.

Steve Collins

My Feedback: (8)

Yes, I had already read the web page you quoted. I also have the programming manual for this radio that was published by Don Edberg which gives a range of 75 to 100 feet. The manual supplied with the radio says "about 30 paces" so I am a little confused as to what is correct. The quote you have above also states that "a jitter here and there is normal'. I stopped at 86 feet when there was just the slightest motion of one of the surfaces. I did not have "the servos jitter significantly" situation at 86 feet. Obviously more range testing is in order because I was not "working all controls constantly" as recommended by the same page as said 100 feet. I am still waiting for a response from Futaba service to a more detailed posting that I sent to them. It will be interesting to see if they recommend something different than all of the above.

lynngordon

I hope you post Futaba's response here.

Big_Bird

My Feedback: (1)

Aptar, I have a 7UAF and an 8UAF transmitter with matching Futaba receivers and if I don't get over 200' glitch free range with the gasoline engine running then I start looking for what's wrong. This is with a fully collapsed transmitter antenna in an open field.

Ken

Ron S

My Feedback: (2)

I agree, 86 feet sounds a little short. Actually, on the Horizon Hobby website, they had a good article written up on how to do range checking. I would hope it's still on their website...

amcross

My Feedback: (2)

Please see the other thread in the ask futaba section.

Aptar, when you get a single surface chattering, try changing your orientation to the transmitter (ie hold it at a 45 away from you, not straight up, not against your chest), etc. When you get SIGNIFICANT movement or movement on all channels is when you've truly failed a range check.

Steve Collins

My Feedback: (8)

I have done another range check following the instructions on the Futaba web page FAQs to the letter. I am now getting a measured 116ft without the engine running and 104 ft with the engine at full power. At these distances I was getting a slight twitch on the rudder only. I am not sure that I can be assured that my interpretation of !QUOT!significant twitching!QUOT! is the same as what Futaba would define it as. Since these latest range figures are beyond the 100 ft distance that the Futaba webpage seems to consider satisfactory, then I guess I am good to go. I will find out for sure either today or tomorrow when the plane is taken up for it's first flight.

This was never a radio problem but rather is an issue with the particular installation environment in the Ultraviper ducted fan jet. With the same radio I did a range check on the same day for my Great Planes Corsair and simply quit walking backwards at an estimated 250 ft without getting any level of glitching.

amcross

My Feedback: (2)

Hi, Aptar! You've hit on one more great example of why giving a "this is a good range" figure is so difficult. Installation matters so much. Also, are the 2 using the same model receiver? Can you switch the 2 receivers and see if either range check fails.

"significant" glitching means the surface is really jumping all over the place, or multiple surfaces are showing more than just a soft chatter.

Steve Collins

My Feedback: (8)

Anne Marie,

They are both using identical receivers; the FP-R148DF that comes with the 8UAFS. I have never had one of these receivers fail and have a lot of confidence in their performance but to make absolutely sure there wasn't a receiver fault or transmitter fault, I installed a new, never used, receiver in the Ultraviper and a new module (same frequency) in the transmitter.