[Elecraft] RFI issues

[Dave New, N8SBE]

(Sorry about the previous blank message -- this is now the ONLY
mailgroup I'm subscribed to that refuses HTML-formatted mail, which is
the default setting for my mail client).

It's amazing the things that can cause issues.  From my experience:


1) An automatic porch light sensor, the kind that screws in the light
socket and then you screw the porch light bulb into it.  It was putting
out broadband hash across several bands, but only at night, when the
light was on.


2) A Mr. Coffee coffee maker that had a little LED clock in the base, so
you could set it to auto-brew in the morning.  That little clock also
put out broadband hash, whose tone tended to vary somewhat depending on
what was currently on the display.  I had to find it using a portable
radio and finding that the kitchen outlets were 'singing' with the
signal.


3) A doorbell transformer, that was mounted on the side of a light
junction box in the basement, located above a false ceiling panel.  The
really annoying aspect was that the transformer didn't seem to be on any
branch circuit.  I finally discovered that the previous home owner had
jumpered a couple of branch circuits in the breaker panel (?!), so
turning off only one of the breakers didn't kill power to some outlets. 
This circuit was shared with the kitchen dishwasher, etc. outlets, and
apparently they had had breaker trips from the overloaded circuit, so
they just jumpered another breaker in parallel.  After running
additional circuits to put the dishwasher and garbage disposal, etc. on
separate circuits (and removing the offending jumpers in the breaker
box), I was finally able to isolate the doorbell transformer, which was
subsequently replaced.


It's been a while since I've done a 'whole house down' survey, and my
noise floor has crept up again.  In particular, I have a broadband noise
that is 20 over S9 that wipes out the top half of 80 meters and all of
60 meters.  I suspect it is my neighbor's U-Verse system twisted copper
pair uplink which operates on those frequencies.




"The second band is used in upstream and start at 3.75 MHz and end at
5.2 MHz " -- https://adslm.dohrenburg.net/uverse/


It's a never-ending challenge...


Good luck, and 73,


-- Dave, N8SBE