Pete737

Went to maiden y P-47 yesterday but on TO power the flaps inadvertently deploy. I am running an airtronics 2.4 system. I was led to believe that this omitted any possibility of interference so I placed the RX directly behind the ignition unit as it was ergonomically convenient. My flap servos are Hietec mighty minis (analog) the rest are digital. I thought that this in itself was a problem but was reassured that the airtronics RX could handle it. Today I have moved the RX back about 10 " away fro the ignition and engine, I have yet to test it. Just wanted to know what you think. Also my G-26 ei began to sputter when given gas yesterday. Not tuning issue, tried to blow down the carb but soe kind of check prevented it. Last night took it apart and cleaned it thouroughly. Just curious if anyone knew of any other possible causes for this, Including the most likely.

Zenoah G-26ei
Airtronics RDS8000 2.4 on 6 volt system

Thanks and best regards. Peter

Nathan King

Did it pass an idling range check?

RCKen

My Feedback: (9)

Pete737,
2.4 Ghz systems aren't "immune" from interference. What they are is they won't interfer with each other when they are on like old 72 Mhz systems were. They are still radio devices and are subject to RF interference in the same manner as older radios were. The same precautions that are taken with an electronic ignition system need to be followed when you are using 2.4 Ghz radios as well.

Ken

Pete737

Yes sir the range check was golden. I have yet to test with the new setup, I will let you know how it turns out.

Oh yeah, Is it me or do you have to have a mechanical engineering degree to install the retracts on the H9-150 P 47.....

Pete

Stew99

Did you abort the takeoff or did you continue to fly with no problems? With the rx placed right behind the engine it's possible that big chunk of metal blocked the signal at some point in the TO run.

Pete737

"A big chunk of metal"? Would you ind explaining that please?

Peter

RCKen

My Feedback: (9)

The "big chunk of metal" he is referring to would be the engine. 2.4 Ghz radios are more prone to having their signals blocked than the older 72 Mhz radios did because of the shorter wavelength of the 2.4 radios. This is why all of the 2.4 Ghz receivers have 2 (or more) receiving elements, with the theory being that if one element is blocked the other one can still receive signal. With this in mind 2.4 receivers, and their antennas, need to have a little thought put in to where they are mounted in a plane. They shouldn't be placed directly next to any large metal obects such as the engine, muffler, langing gear, or such. Care also needs to be taken when mounting next to carbon fiber parts as these can shield the antennas as well. If you placed your reciever directly behind the engine of your plane it's entirely possible that the metal of the engine blocked signal from the receiver, which could have caused your problems.

Ken

Pete737

ok. Would a metal pushrod to the throttle be a posible problem?

carlosponti

My Feedback: (1)

2.4 from what i read in my futaba manual also have problems with carbon fiber and certain composite materials. transmitting through carbon fiber was listed as something to be aware of.