Re: which receiver?


Phillip Fimiani
 

Noise can be coming form anywhere...

Computers
Monitors
CFL lamps
LED lamps
X10 modules and now Insteon with UHF control in parallel with the zero crossing signal on the AC
WiFi
Ceiling fans! They shouldn't hum! (see below)
local radio stations (within a mile) 5KW-10KW

All in my den/radio/computer room
Its a wonder I can receive anything at all! But I do....

I do have an up to code electrical grounding system (3 grounding rods) for my house AC and there is almost no resistance between that and the ground rod I use for my radios. (great ground water underneath the lawn)

I could probably do with putting on some supression beads on some equipment. But one can go crazy doing that... http://www.k0bg.com/beads.html

Try turning off devices to see if the noise goes away.
Most everything manufactured today needs to meet  emission standards, but.... Cheap items may not....

I recall a scanner that wiped out some medical telemetry... The solution was to remove it to a more distant location away from the receiver. Watch out for plastic box type appliances....

Check AC wiring for correct polarity and grounding. I delt with a noisy ceiling fan that liked to take out light bulbs. Eventually when replacing it I found the Hot and Neutral were reversed! But that also caused the fan to be quite noisy (AC Hum) Don't know if you have 220v to ground or 110v-gnd-110v but good grounding is still important.

Operating on battery should remove many of the interference problems but bad grounds can cause all kinds of noise.

In regards to CFLs or straight fluorescent tubes....They use solid state ballasts which if bad can radiate all kinds of noise, yet the bulb doesn't flicker. Turn them off one at a time to see if there is a change. You can oprobably say the same for LCD displays and their backlight power supplies. They are just high voltage switching supplies.

Try operating your portable in different locations in the house....Go outside too... There could be a bad AC transformer causing the problem

For your entertainment .....appliances can coexist!

Here's someone in your backyard!  https://www.youtube.com/watch?v=g-LaKTFoh90
 
 
One serious shortwave listener!

Best Regards
Phil
WA2069SWL
Lat: 40.8367633  Long: -74.1768412
 



From: "Hans Stam hansstam@... [ultralightdx]"
To: ultralightdx@...
Sent: Monday, September 8, 2014 7:52 AM
Subject: Re: [ultralightdx] which receiver?

 
Thanks for the reply..
 
But do you have and others experiences with electric noise etc? That was also one of my question..
 
Hans




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