15 Oct
2000
15 Oct
'00
2:49 p.m.
From: R. D. Davis <rdd(a)smart.net>
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. 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