Jumping control column - from radar??

[andy]

I received this in an email today, so I decided to post it so folks can offer other suggestions to help this tech out.

Your answers will count towards your final grade. jimi1:

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I am working with a site that has a vintage late 1980's CAE sim.

The column jumps occasionally for no apparent reason and it has been suggested that it may be to radio/radar interference at the airport. Using a walkie-talkie under the frame also causes the column to jump. Most of the hardware has been changed and checked without success. Has anyone had a similar problem and if so how were you able to solve it.

Thanks in advance for any assistance you can offer.

<name removed>
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[Wible]

Our vintage 80's CAE ship did that a couple times over the years, and it turned out to be a dirty pot for the pitch trim.

[msthomas]

We had a similar situation for years here on our DC-9. It always seemed to get worse in the fall and winter and then would taper off over the summer. Turned out to be a real odd ball thing. Every time the cooling fan on the hydralulic pump turned on we got the jump in the controls. We never really figured out why this was happening but changed the power source for the cooling fan and that took care of it.
I'm not saying that's your problem but it could be something as odd as that.
Good luck!

[Doctor Clutch]

We had a similar problem with several late model Singer AST sims. The motion would also bump. The building was new at the time and the contractor (MS Mortensen) was still working on last minute repairs. They were using high power ( 5 watts) walkie-talkies that when keyed up in close proximity to the sim would cause the glitch. We made them stop using the walkie-talkies and never did do anything to the trainers. Later we used low power walkie-talkies and didn't have any problems. Cell phones don't seem to create problems either. Good Luck.

[fuzzymike]

I have seen problems like this with 80's vintage CAE machines that were caused by cell phones especially Nextels. My Nextel would cause problems such as this. I believe it polled for a tower every so often. At least that is what it appeared to be doing. I know it was transmitting because it could be heard through speakers.

[guest]

unless someone is seriously violating FCC regs, I'd look away from the stray RF as possibility.

RF energy dissipates quickly the further the distance from the source.

If the sim has worked fine for years, and your neighbor hasn't installed a Radio Marti Tower, look elsewhere.