[600MRG] 630M Noise Reduction

[Rik Strobbe]

Hello Paul, all,


"One of the worst offenders was a Wall Wart converter that had more noise on 630 meters when the electronics it was powering was off than when it was on. That one went in the trash."


This is typical for bad designed (= cheap ??) switched PSU's. They use simple PWM (pulse width modulation): the lower the power consumption of the load, the shorter the pulses, the more harmonics it produces.


73, Rik  ON7YD - OR7T


________________________________
Van: 600mrg-bounces at mailman.qth.net <600mrg-bounces at mailman.qth.net> namens Paul Signorelli <w0rw1 at msn.com>
Verzonden: woensdag 23 januari 2019 16:55
Aan: 600MRG at mailman.qth.net
Onderwerp: [600MRG] 630M Noise Reduction

Tracking 630 meter noise is really hard.
   I have a little AM transistor radio that helps me to trace offending radiators.
I also use my BC-453 that has an "S" meter.
So I bought a bunch (10) of Schaffner FN2080-3-06 (3A) Power Line Filters and put them
on all the worst radiators around the house.
   I have a higher current filter, Rockwell Automation 2090 for bigger power supplies.
Then i built a RFI filter for my Battery Chargers using 2 big Sprague  10JX34, 10A, feed coaxial feed filters.

(I don't mind noisy things that I can switch off or unplug, I have them tagged.
My XYL's new Speed Queen Washing machine has gobs of digital noise coming out of it,
again, even when it is off. I contacted the factory and told them the "Off" switch doesn't turn the machine OFF !, They said I need to buy a line filter, that has no specs).

   But there seems to still be noise out there coming through my antenna.
I installed a battery back up switch-over system for my K3s and waited.
Yesterday, something blew a power line breaker and the whole neighborhood lost
power.  Happy day, My K3s was finally running in an area where there was no
local power.
The noise was still about the same and but now I have a noise base line and
know most of my house noise has been eliminated.
   One of the worst offenders was a Wall Wart converter that had more noise on 630 meters when the electronics it was powering was off than when it was on. That one went in the trash.
Paul   w0rw
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