[Boatanchors] Need magnetic shield for shaded pole motor

[J. Forster]

Hardware stores and home centers often have displays or rod and angle
stock. Those displays often sell expanded steel mesh in roughly 2' x 3'
sheets for radiator covers, etc.

-John

====================

> One has to do a bit of hunting, but perforated or expanded steel mesh is
> available.
>
> I erred once again.  My mind went in the RF shielding direction. ( I
> mentally went into thinking Faraday Shielding.)
>
> Soft steel will definitely work better.
>
> Heavier steel would be even better, however, wrapping a transformer or
> shaded pole motor with it then brings heat dissipation into the equation.
>
> Finding expanded mesh steel for use in our hobbies is a pain. Most
> suppliers do not want to deal in small sizes or quantities.
>
> It may also be harder to locate also.
>
> The last thing is cannibalization of older radio gear final cages.
> These "normally" in older gear, steel.
>
> Later cages are aluminum.  Much less effective, although magnetic
> properties through eddy current is used still.
>
> Bob - N0DGN
>
> On 1/2/2014 2:33 PM, Al Klase wrote:
>> Jim,
>>
>> Non-ferrous metals, copper etc., will do little to attenuate a
>> magnetic field. There is an alloy, know an mu-metal, that was designed
>> just for such applications, but it's expensive and hard to come by.
>> Google same. Start here:
>> http://www.pmlindia.com/hi-perm/Magnetic-Shield.htm?gclid=CJ3ghvWc4LsCFTNp7AodLUsAmA
>>
>> However, mu-metal only has a slight edge over soft iron or even steel.
>> The coffee can may be a little too thin. The wreckage of a LARGE
>> transformer may be the place to start.
>>
>> Al
>>
>> On 1/2/2014 2:22 PM, Charlie , W5COV wrote:
>>> I keep some handy copper sheets on hand all of the time now, comes in
>>> handy for various projects. This that I keep on hand, can be cut with
>>> scissors, and is relatively cheap, as am I <grin> .
>>>
>>> I picked it up from a from a place called Electronics Goldmine.
>>> http://www.goldmine-elec-products.com/
>>>
>>> Really handy to have around.
>>>
>>> Usual disclaimer no financial interest, just a satisfied customer.
>>>
>>> Charlie, W5COV
>>>
>>> On 1/2/2014 1:14 PM, rbethman wrote:
>>>> Use either the cut up coffee can as John suggests, they ARE becoming
>>>> another rarity.
>>>>
>>>> Now the coffee is coming in plastic containers. :^(
>>>>
>>>> Copper is still available as a roofing/flashing item in the Home
>>>> Improvement stores.
>>>>
>>>> I have procured some silver plated copper expanded mesh some years
>>>> back.
>>>>
>>>> It was offered on one of the mailman.qth.net lists. It may have been
>>>> this one or it may have been the glowbugs list.
>>>>
>>>> Bob - N0DGN
>>>>
>>>> On 1/2/2014 11:33 AM, J. Forster wrote:
>>>>> A cut up coffee can? Seriously.
>>>>>
>>>>> -John
>>>>>
>>>>> ============
>>>>>
>>>>>
>>>>>> Any ideas for an effective Gaussian shield for an open frame
>>>>>> shaded pole
>>>>>> motor or a source for very high permeability transformer core uncut
>>>>>> sheets.
>>>>>>
>>>>>> Thanks for any ideas--- Kindest regards Jim K9AXN
>>>>>>
>>>>
>>>
>>
>
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