[RFI] Noisy Uninterruptable Power Supply (UPS)

[Wes Stewart]

 These got delivered Friday.  I was appalled at the condition of the two boxes.  The boxes had been severely damaged somewhere along the line and about a roll of package tape held them together.  The actual cartons for the UPS were about half the size of the shipping containers and were flopping around inside.  Remarkably they seem to be intact and the UPS were cushioned in molded foam blocks.  I've only opened one so far because I still might return them.
A (really) preliminary look at RFI using my Perseus SDR and a single-turn loop shows some garbage while the unit is powered.  It gets much worse when it goes into backup mode.  Unfortunately, I discovered that the switch-mode wall wart supplied with the Perseus is noisy too, so I'm not about to stand behind any measurements made so far.
I've ordered linear 5V wall wart to power the Perseus and then we'll see what happens with a cleaner setup.  I should note that I don't hear any of this on the station RX, but my antennas are a 100 to 150 feet away from the shack.
Wes  N7WS


    On Wednesday, June 14, 2023 at 11:56:23 AM MST, Wes Stewart <n7ws at yahoo.com> wrote:  
 
  I ordered two of them.  If they don't work out, it is Costco and they take them back no questions asked.
Wes  N7WS/rfi