Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!mailrus!iuvax!bsu-cs!cfchiesa
From: cfchiesa@bsu-cs.UUCP (Christopher Chiesa)
Newsgroups: comp.sys.amiga
Subject: Re: Radio interference
Summary: More info on MY situation
Message-ID: <3883@bsu-cs.UUCP>
Date: 8 Sep 88 20:03:07 GMT
References: <8808291952.AA12795@cory.Berkeley.EDU> <11@richsun.UUCP>
Organization: CS Dept, Ball St U, Muncie, Indiana
Lines: 41


I contributed a week or so ago to this topic and have since determined a few
more bits of data on the situation here.

I find that the presence/amount of RFI interference I experience (@ 93.1 MHz
on FM band) seems to be determined by the presence/length/position of AUDIO 
cables from my 1000 to my receiver.  Currently, the 1000 is about 15 feet from
the receiver; I can connect its stereo audio output to my receiver by using a 
combination of audio cables and adapters (the cables are of several different
plug-to-plug configurations).  Additionally, the receiver is "behind" me as
I sit at the keyboard, so the "shortest path" for the cables is UP and OVER
the main CPU box.

So.  I find that I experience RFI whenever these long audio cables are con-
nected to the 1000, regardless of whether they are actually plugged into the
receiver or are just lying there unterminated.  However, I find that the AMOUNT
of interference can be made to vary greatly merely by changing the ANGLE at
which the cables pass over the top of the CPU box.  Straight front-to-back
seems to be worst, while "skewing toward the right as we come forward, and 
wrapping around the right front corner" seems to be best -- almost NO inter-
ference at that point.  I haven't noticed much of ANY RFI interference AT ALL
when running short, single cables the foot and a half from the 1000 to my 
monitor.

(Note 1:  The "skewing..." path places the first 2' or so of audio cable
almost at right angles to the straight line between the 1000 and the FM
receiver; significant?  Who knows.  There's a good 12' more that wanders
haphazardly across the floor...)

(Note 2:  A friend of mine who was present when I first discovered the RFI
problem, went home and checked on the situation; he reports he experiences
the same problem, against the same FM station (a relatively distant and 
weak one to begin with), using a C= 64.)

Just thought someone might find this information interesting or useful.

Chris


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