scottsey

Here is what I have and what I have done so far: Futaba skyport radio, three tower servos, and two futaba servos. I believe the Tower servos and Futaba are the same? Anyway this in a Pheonix Funstar so I have one Y connector and two extensions, one for the elevator and one for the rudder.

I have glitching with the antenna down, motor not running. Glitching starts at about 60 to 80 feet away from the plane. It varies from I slight buzz to severe glitching. By severe I mean all control surfaces will move the complete amount of throw by themselves!

I have tried a different Tx and Rx with the same results. I have tried a different switch and different battery pack with the same results. Last night I tried unplugging all servos and then plugging them in one by one. The problem still persists. When only one servo is plugged in, doesn't seem to matter which one, I will just get a very slight buzz then has I plug more in it gets worse!

What am I missing? This is driving me nuts! I welcome any and all ideas.

Thanks

dadrivet

The Range May Be Slightly Down But Seems Pretty Average,Make Sure All Bateries Are Fully Charged And Try Different Angles When Checking Range

Martin

scottsey

Thanks for the response. The batteries are fully charged and I have tried different battery packs. As far as different angles that does seem to make a difference. It will be perfectly still with no buzz or glitches but if you change the angle it bit it will start glitching. Shouldn't I be able to get at least 100 feet away with no noise or glitching?

Silent-AV8R

This is straight from the manual for that radio:

Always test your digital proportional R/C set before flight. As
a simple test method, before starting the engine, retract the
transmitter antenna fully and operate each servo from a distance
of about 5m and check if the servos follow the movement
of their control sticks.***

Now 5 meters is 16.4 feet. SO if you are getting 60 to 80 feet you are more than OK.

scottsey

Maybe I am just being too cautious, but I am sure that I read somewhere you should be able to get 100 feet away with antenna down without any glitches. Does anyone else have an opinion on this. I really don't want to crash this plane. How far away do you think I should be able to get from the plane with the antenna extended (with the plane on the gound not running) before glitches occur?

thanks

Rodney

IMHO you should have a minimum of 100 ft. of range with the antenna on the transmitter down, anything less is a recipe for disaster. If you can, change out the Y harness, some of them are quite poor in-so-far as in line impedance goes. If you have any extensions, change them out if you can, sometimes just unplugging and replugging them in helps as many of the less expensive ones also quickly build up impedance due to corrosion on the connectors themselves (the unplugging and replugging wears this away temporarily). As an aside, never use an extension where you do not unplug and replug occasionally, no matter how good the connector is.

scottsey

Thanks Rodney. That is what I thought. Here is what really has me stumped though. I unplugged every servo except the throttle which does not have an extension on it. It would still buzz slightly. It had no movemant or glitching just a bit of a buzz. Is that normal? I don't have another y harness but I guess I will have to get one. I should probably get longer connectors for the elevator and rudder. The ones I had were a bit short so I added two more short ones which make for a lot of connections.

Silent-AV8R

Just so I understand you, the DIRECT QUOTE from the MANUAL for your radio is not good enough. You want the opinions of unknown persons on the internet? Is that right?? Oh well.

Here's my opinon, read the manual and follow what the people who make the radio have to say. It is just possible that they know more about their product than most others do. Just a guess.

scottsey

I sure don't want to argue with you but I have the manual out and that "direct quote" is not in my manual. The model of the radio is a Futaba 4YBF. Maybe we are talking about different models. In fact my manual doesn't say anything about a recommended distance. I do know that my past experience tells me that I have been able to get 100 ft. away without any glitching problems. So I am not sure what is going on.

Thanks for your help.

JohnBuckner

My Feedback: (1)

Just on a hunch and if I,am all wet please forgive me but I,ve seen plenty of nice new airplanes show up at the field with the the antenna still neatly coiled up with the tie wrap.

If thats not not the case then how have you arranged the antenna? As this will tend have an effect on the range a bit when you are testing near the limits with the antenna down.

As Rodney suggested with a modern Dual conversion Rx I am a little skeptical with a check less than 100 feet however as mentioned above some manuals for some Futaba Rx's have suggested a bit less. The figure of 75 feet seems familiar, Probably the less expensive units.

John

scottsey

I have the antenna out the side of the plane than back to the tail. I do have the antenna near the switch. Don't know if this could cause any problems but just in case I am going to move it further away.

Thanks

mglavin

My Feedback: (31)

What are you using for battery power? Regulators? Standard switches? Any fancy electronic wyes or extensions?

Have you tried removing the ignition system battery and testing?

Does the glitch persist with the antenna extended?

When you tried different TX, RX and battery were they like model components?

Silent-AV8R

My mistake. When you said you had a "Skysport" I assumed that it was the Skysport 6VA. That is the manual I quoted. I cannot find that model listed on the Futaba site.. There is a 4 NBF and its manual says 20 to 30 meters (65 to 98 feet). So you are still right in there. Sorry for the mistake. The Skysport 4VF only says to check functions are correct. Basically, I feel you are getting acceptable range and should not worry about it so much.

Silent-AV8R

Some data points:

Range recommended for a -

JR 9303 (per page 12 of the manual) = 60 to 75 feet

Futaba 9ZWCII = 30 "paces" +/- 90 feet

Notice neither one is at, or above, the above mentioned 100 feet minimum.

scottsey

Thanks for the help guys. Last night I checked to see how far away I could get with the antenna extended before any glitching occured. I would estimate that It didn't show up until approximatly 200 yards away. Maybe this is good enough?

scottsey

mglavin, I forgot to answer your questions. Yes the Tx and Rx were like componets. Yes I do have one Y and extensions. I am going to replace the Y just in case.

mglavin

My Feedback: (31)

I would also replace the string of extensions you noted previously as well. Electrical losses abound when multiple connectors are employed. Stay away from low quality NON gold plated connectors; we've realized many problems with same.

Are you using NiCads?

scottsey

Yes I have NiCads. No my extensions are not gold plated.....Yet! They will be soon.
I had sent a question to Futaba. One thing they mentioned is the fact that the transmitter should not be left on with the antenna collasped for more than a minute or two. I had never heard of this. We have left it on for long periods of time with the antenna collasped while using the simulator. Does anyone think this could be the problem?

Rodney

Scittsey, The prolonged running with the antenna collapsed is hard on the output stage of the transmitter. Any time the antenna is not fully deployed, the SWR (standing wave ratio) goes way up and, instead of the rf being radiated, it is converted to heat in the final output stage of the transmitter. This can cause problems and will definately lower the mean time to failure of the unit. Mean time to failure doubles for every 10 degrees centigrade that the temperature rises. There will be a point when the heat is enough to cause excessive migration of the doping in the output stage which will cause leakage and loss of efficiency and, in some cases, catostrophic failure. You were given good advice, never run for more than a couple of minutes with the antenna collapsed or even partially collapsed. When running on your simulator, try removing the crystal in the transmitter which should kill the rf section. Did you ruin yours, probably not but a good check is to see if a known good transmitter on the same frequency gives you the same jitter problems with your unit. If so, your transmitter is probably not at fault.

scottsey

Thanks for the info Rodney. I did not know that. We will no longer do this!!!! I hope we haven't damaged the Tx.

dirtybird

My Feedback: (5)

I sounds like you ought to have your transmitter checked for power output. Its simple to do if you have the instrument for it. See if you can find someone in your erea that has one.

scottsey

Problem solved!!!! Today I purchased a new Y extension and a new straight extension. The Y is shorter than the one I had on and both are heavier gauge wire. I would have replaced both straight extensions but the hobby shop only had one. I live in a small town and this hobby shop is small and doesn't keep a very large stock of parts. Anyway after replacing both I could get about 180 feet from the plane before any glitching occured! At this point I don't know which extension was bad.....I know I should have only done one thing at a time but I am impatient! Anyway later I will probably replace the old parts one at a time to see which one was the culprit. For now I am just happy that we can fly the plane. Now if the 25 mph wind would just go away......oh well maybe tomorrow.

Thank you all for your help.

mglavin

My Feedback: (31)

Its rewarding to realize, identify and remedy a problem as such. Have fun flying the beast.

It’s another NOISE related entry for my database, this problem is far more common than most realize.

While your TX is being used for a simulator I assume it’s powered down and not generating an output signal? If so NO problem.