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Raymarine raytheon 4Kw Radome array question
In article ,
(C. Sadler) wrote:
I've got a unit that is about 7 years old.
Recently, it started turning erratically, causing the display to
pop the Antenna not rotating message, and shutting off.
The antenna's turning, but slows about every 1 to 1.5 revolutions.
I've changed the belt, and had a good look at the unit. It appears
clean, and uncorroded.
I'd like to suspect the stepper motor, as that would be a pretty cheap
fix, but before I go there, I'd like to hear some opinions of what
else might
be causing the stepper to speed up and slow down like that.
TIA
A few of things to look at:
1. Do you actually see the antenna slowing down when it is
turning? Check the motor drive elecronics if it does.
2. The feedback signal from the antenna to the display is usually
a pulse stream that is generated by the motor, or some type
of chopper wheel - LED/PhotoDetector system. Put a scope
on this pusle train and see if it is changing frequency
When the motor slows down. Chopper wheel holes can get
plugged up with water or particals, and cause the pulse
train to be missing a few pulses/Rpm and cause your symtome.
3. Check for intermitant shorts, or opens, in the Feedback
Signal Wire, from the antenna to the display.
Bruce in alaska
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add a 2 before @
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