[RFI] New RFI Source

AA5CT jwin95 at yahoo.com
Mon May 27 13:48:46 EDT 2024


 Well, thinking here is a bimetallic strip feeding a heating element would be broadband,as there is nothing periodic in that like a 35 kHz swticher for instance,
Oh - I have tracked down a couple doorbell transformers, one that was activated by the 
switch continuously and must have overheated and buzzing as the overload thermostatcycled, and another that failed in the Texas spring to summer transition and that onetoo was cycling and creating a cyclic buzz.
So, more to chew on.
de AA5CT Jim


    On Monday, May 27, 2024, 11:13:52 AM GMT-5, K9MA <k9ma at sdellington.us> wrote:  
 
  On 5/26/2024 11:23 PM, AA5CT wrote:
  
 Another possibility - aquarium heater? One of those jobbies that clamps over the edge of the 
  aquarium in a glass tube maybe an inch diameter and 4 or so inches long. 
 
I did once track down one of those, but it had the characteristic spectrum of a switching supply. This one emits absolutely flat broadband noise, more like a spark gap. It is on for about 1 second every 4 seconds. I'll do some more tracking today.
 
73,
 
Scott K9MA
 
 -- 
Scott  K9MA

k9ma at sdellington.us   


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