[RFI] RFI & Alarm Systems?

KD7JYK DM09 kd7jyk at earthlink.net
Thu Aug 2 20:53:12 PDT 2012

: There is one I drive by nearly every day that wipes out a portion of the
: 440 band.

What exactly are you hearing from it?  Intentional RF or incidental?  There
is an ISM band (Part 15) from 433.05 to 434.79.  I usually monitor 433.925,
434.000 and 434.500, but I have equipment operating throughout that range.
Almost forgot 418 MHz, lots of stuff there.  Alarms operate throughout the
spectrum.  I have a transmitter next to me that operates from 150 - 276 KHz.
Then there was some stuff around the AMBC band, article surveillance systems
throughout HF, MILLIONS of devices covering six decades around 27 MHz, then
49 MHz, also some stuff around 33, 40, 72 and 76 MHz, 150 MHz, 210-215 MHz 
or so,
250, 275, 290, 303 and 308 are quite common, as are 315 and 318 MHz, then
there was the stuff in the 80's that didn't change codes, but frequencies,
290-410 or so if I recall correctly, 434 is common, commercial stuff around
450-470 MHz, the entire analog cellular band, but 868 MHz is the most common
now, throughout 902-928 with stuff centered on 915 MHz being the most common
and now 2.4 GHz where the garbage out there exceeded all other bands
combined long ago!

If you want to know what frequency your equipment operates on, check the FCC
ID database:



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