[Boatanchors] Need magnetic shield for shaded pole motor

[Jim Wiley]

Have you considered replacing the AC motor with a (mostly) similar unit 
from another vendor?  Not all units will have the same problems.

Or even using a DC unit salvaged from a computer?  I don't know what the 
physical requirements, mounting, amount of air needed, etc. need to look 
like, but that may be a workable solution.  Coming up with the necessary 
DC should be easy.  Such fans draw comparatively little power, typically 
on the order of 150 to 200 mA, and could be sourced from a simple DC 
rectifier + filter + 3-pin regulator (perhaps a doubler if 12V is 
required) running from the filament supply.  Such a fan should have 
virtually no external field. .

Just a suggestion, perhaps worth what it costs.

- Jim, KL7CC


On 1/2/2014 11:43 AM, james.liles at comcast.net wrote:
> Here is my problem: I am trying to mitigate a minor HUM problem with a 
> transceiver that uses a shaded pole blower. Worked on the Hum problem 
> for far too many hours and found it to be the blower motor ----- Who 
> would guess???? The shaded pole motor has an incredible amount of 60 
> cycle magnetic leakage extending out to about 3 inches.