Hi Mark,
I think what you have here is a switching power supply. I have found that
the most often overlooked source of interference is caused by the switching
supply radiating switching transients back down the AC line.
The first thing I would try is to plug the supply into a different breaker
box branch and see if that makes a difference.
The next step is to install an AC line filter like those made by CorCom.
These are frequently seen at hamfests. Just be sure to get one with
adequate ratings for your monitor. Take a look at www.corcom.com
You might also see if you could locate a non-switching supply to run your
monitor, i.e. a linear supply.
73,
Gary
++++++++++++++++++++++++++++++++++++++++
K9GS
Gary Schwartz e-mail: k9gs@arrl.net
Society of Midwest Contesters (SMC) GMDXA
++++++++++++++++++++++++++++++++++++++++
----- Original Message -----
From: <MZAVATSKY@FAIR1.FAIRFIELD.EDU>
To: <rfi@contesting.com>
Sent: Saturday, November 04, 2000 07:21 PM
Subject: [RFI] Power supply interference
>
> I recently purchased a NEC flat panel monitor which I like very much, my
> problem is the small power supply that came with it. The ps is giving me
alot
> of junk on hf I know it is the ps because even when I disconnect it from
the
> monitor the interference doesnt go away until I unplug it from the wall, I
> wrapped both ends (it is the kind that has a cord that goes to the monitor
> and one to the outlet unlike a wall wort hi!) with ferrite donuts and it
did
> nothing.. I guess my question is there a place that sells power supplies
like
> this that maybe better filtered it,s specs are input: 100-240v 1.2A
> output: 12v 4A center pin + , I went to Comp USA and RS but no luck I
would
> really like to just replace it with a better one if I knew where to maybe
> get one, also when I actually touch the supply itself the noise goes up
and
> down I beleive that the Ps is just a junky unfiltered one I had a problem
like
> this once in the shack with another piece of equipment and just found a
comp-
> atible one of the same specs and replaced it except that one was a little
> easier to find then this one,, any ideas or comments are appreciated Thank
> You 73,s
> Mark Zavatsky K1ZZZ ex: HL9WK
> Fairfield,CT.
MZAVATSKY@fair1.fairfield.edu
>
>
>
>
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