John & Annette Nicholson wrote:
>
> Arghhh...I'm listening for the 8Q7 operation thru
> a wall of noise...caused by a neighbor charging up
> her electric mini-wheelchair. I traced the noise
> down last night but does anyone know why this contraption
> would cause noise 3.5 - 29Mz with an S9+ girgling
> noise every 5Khz? What components in the charging
> circuitry should I look for as culprits? Obviously
> the gal needs to get around her home...
>
> Thanks in advance,
>
> John K7FD
> http://www.netbridge.net/dx
>
Hi John. It probably uses a switching type power supply to charge the
chair. Those things are wide band signal generators. Some TV sets have
terrible supplies in them. Then can be quieeted down, but takes doing
some work to them-putting toroids on leads, putting filters in them. Good
luck!!
Tom W7WHY
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