🚀 go-pugleaf

On Thu, 25 Jun 2009 16:31:09 +0800, TonyS <scarborofun@gmail.nspm.com>
wrote:

>John Larkin wrote:
>> On Wed, 24 Jun 2009 21:42:07 -0700, <castlebravo242@att.net> wrote:
>> 
>>> "David L. Jones" <altzone@gmail.com> wrote in message 
>>> news:h8B0m.53620$FI5.3564@newsfe12.iad...
>>>> Check out a rather unusual phenomenon you can see on your oscilloscope in 
>>>> my latest blog (#14):
>>>> http://www.alternatezone.com/eevblog/
>>>> See if you can get it to happen on your scope!
>>>> I'll offer a free subscription to my blog for the best screen shot posted 
>>>> :->
>>>>
>>>> Oh, and the probe doesn't have to be shorted either.
>>>>
>>>> Have fun.
>>>> Dave.
>>>> -- 
>>>> ================================================
>>>> Check out my Electronics Engineering Video Blog & Podcast:
>>>> http://www.alternatezone.com/eevblog/
>>>>
>>>>
>>> When I worked a Century Data we had a problem with our new reel to reel 
>>> vaccuum column tape drive when ever someone would walk by the drive when it 
>>> was reading it would get data errors. The problem was that the shield on the 
>>> cable from the heads to the preamp was grounded on both ends.
>>>
>>> Bob 
>>>
>> 
>> That's usually the best way to ground shields.
>> 
>> John
>> 
>> 
>
>IIRC head signals mostly went via twisted pair. If they had a shield as well we 
>would certainly not ground them on both sides.
>

You *want* large amounts of high-frequency common-mode noise?

John