[TowerTalk] Alfaspid acoustic noise?

[Pete Smith N4ZR]

Sounds like a tough one.  In addition to direct sound radiation, you may 
also have to deal with the noise coupling to the tower through the 
rotator mounting bolts, and to the antenna through the mast clamp.  I 
almost hope it's a hardware failure rather than "just the way it is."

73, Pete N4ZR
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On 5/8/2013 10:11 PM, Jim Miller wrote:
> My Alfaspid works fine but does make quite a grinding racket. Mine is only
> up about 35ft as I have a rather short crankup. If it was at 100ft no one
> would notice of course.
>
> >From the sound it makes it sounds like just the noise from the wiper motor
> whirring away but it does produce quite a growl. Since it appears to be
> just a repurposed windshield wiper motor I'm a bit surprised at the noise
> level produced.
>
> I've had the rotor apart just a bit to peek in the top and nothing seems
> amiss. The top doesn't seem to do anything other than support the split
> rubber grommet and keep crud and water out. As far as I can tell it doesn't
> provide mechanical support on any axis.
>
> I was thinking of cranking the tower down and removing the grommet and
> lifting the cap so that I could watch/listen while it rotates to try to
> determine the real source of the noise.
>
> I was also thinking that if it is just "normal" I could try constructing a
> cylindrical muffler that I could wrap around the rotor made of a hard
> surface lined with foam to try to reduce the noise a bit.
>
> Neighbor who goes to bed early is complaining a bit...
>
> Suggestions anyone?
>
> Thanks
>
> Jim ab3cv
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