[Milsurplus] Power supply RFI

Clarence M. Owens [email protected]
Sun, 19 Oct 2003 16:06:07 -0400


Hi Pete,

I'm not familiar with that particular power supply but I have had RFI
problems in the past with linear regulated power supplies.  One in
particular was very sensitive to HF or VHF RF on its output leads and I was
able to solve the problem by placing .05 microfarad 500V disk caps across
the output and from each side of the output to ground.  All leads are very
short.  I also wound several turns of the output cable on a large ferrite
core as close to the chassis as I could for good measure.  Those steps
completely cured my strange PS behavior so I did not put another core on
the AC power cable but that might be necessary in your case.

One note:  the PS I put the caps on has remote sense connections on its
barrier terminal strip and I think the RF on the unbypassed sense input
lines was what really caused the erratic behavior.

Good luck and please let us know what worked when you get it running
correctly.

73, Clare  N2RJB



                                                                                                                                          
                      "pete williams"                                                                                                     
                      <[email protected]                                                                                               
                      .au>                                                                                                                
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                      10/18/2003 03:50 AM                                                                                                 
                                              Subject:      [Milsurplus] Power supply RFI                                                 
                                                                                                                                          



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 G'day  all,

I use a  HP 6269B  supply to kick the dyno along on ART-13,  and the
like with a 28 V battery to handle the starting current.
Witha 0-40V and 0to 50 amp  adjustable rating, it all works fine until
the RF  from the TX invades the  space and  the PS either oscillates
or shuts down.
It's one of these constant voltage /constant current boxes with a
series regulator and a triac preregulator. I think their main use  was
for  battery charging.
Our 240V 3 wire input line is  grounded appropriately.
Maybe someone can suggest where  bypasses/ferites etc can be placed...
I 've got a manual/schematic. Alternatively a signal to HP /Agilent
may turn up suggested  cures, but thought someone with connexions over
there may have been this way before.
Pete VK 3 IZ
--
Pete Williams
[email protected]
METUNG AUSTRALIA 3904

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