Just in case anyone has had any experience with this one...
I've been having a major RFI problem on HF for a couple of years. Recently
I went DF'ing and found... myself. I have an Eagle-One telephone system
in my house and when I turn it off... silence!!! At first I suspected the
switching power supply and the KSU but the source of the RFI is actually
the station sets themselves. However, adding 3-pair RFI filters at the
stations only reduces QRM by about half.
From disconnecting and reconnecting the station sets it looks like the RFI
begins when the LED display is illuminated. There is about a second delay
after connecting the station set before the uP starts multiplexing the LED
display. What has specifically led me to suspect the LED display circuitry
is that during initialization the dots in the colon are toggled on and off
a couple of times, upper, lower, upper, lower, etc. Afterwards, the time
is diplayed. The sound pattern of the RFI seems to follow the visual
pattern of the LED display.
Before I dig into a station set, has anyone had experience with Eagle-One
telephones or perhaps RFI from multiplexed LEDs?
Thanks!
Andrew Gerald
N2CBU
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