[Elecraft] QRM and filtering

[Joe Subich, W4TV]

They are cheaply built with little insulation.  A good power
surge or lightning strike will puncture the insulation and
the primary will arc to the frame/core on peaks of the wave.

Door bell transformer failure will have a marked 120 Hz rough
note.  The homeowner should consider themselves lucky if you
find it for them as old transformers are often simply screwed
to floor joists under the floor in the area of the front door.
The arcing represents a fire hazard.

Fortunately, more modern door bells, etc. eliminate the old
transformers.

73,

    ... Joe, W4TV

On 10/22/2010 10:49 PM, Jim Miller wrote:
> What is there about a transformer that causes so much grief? Curious...
>
> 73
>
> jim ab3cv
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