48v dc power

From: Joe <rigdonj_at_intellistar.net>
Date: Mon Oct 16 09:14:44 2000

  Allison,

At 10:49 PM 10/15/00 -0400, you wrote:

>
>
>>Out of curiosity, what's the furtherest distance anyone here has
>>noticed RFI from their systems (open or closed)?
>
>
>400ft, 10mhz clock for a S100 z80 system that was also distributed to
>other boards on the bus. A modification to the termination of that line
>virtually made it disappear, the standard terminators didn't actually
>match the impedence of the line making it antenna. Other hot one
>was the Altair you could hear the 2mhz anywhere in the house
>with the case on.

  Was that being ratiated via the AC power lines or the keyboard cable or
what?

    Joe


 Usually if you can isolate the freq you can tame
>it. one that get me every time is the 15700 hz horizontal retrace
>from TVs with most monitors running second, all plastic cased.
>
>Most stuff in a metal box with screws in tend to be quiet and
>commercial systems like DEC, SUN and HPs in full dress
>tend to be quiet if made to the specs in effect after 1980ish.
>PCs however are all over the map, some excellent and
>some very poor.
>
>Allison
>
>
>
Received on Mon Oct 16 2000 - 09:14:44 BST