[RFI] S FL Noise help

[myles landstein]

hi Kirt. appreciate the. response

I’ll try to take a stab at the questions you asked…

the freq  range was. 440-449.  
mode FM 
types of receivers,  Commercial moto or kenwood mobile radios, also various brands ham HT’s
antenna used mobile dual band diamond,  ht’s. =rubber duck
areas. were. as mentioned. as it was all over.   i didn’t find a place w/o the. noise. i don’t have the ability to really drive around. and denote a block that might be rf quiet vs a block that is noisy. as it is all over a vast area. 
I can try to make some recordings.  in a day or so, but not sure how/where i can post them
strength was normally s9

did i have electronics. on me, == they were removed.  for testing noise persisted   i’ve not heard this noise. anyplace. else. but it’s so wide spread n prevalent. in this s fl. region i am positive someone must know what it is :)

I have not tried to listen. around 434

am new here so can’t say if there are any radar like. set ups.  

happy to provide any info.    i think i covered all your questions.  happy to provide more info.  and. can make a recording soon if you can suggest where i can upload it

again , thanks so much for responding.  the noise is annoying. for sure but am also curious what it is and if it is ‘legal’ or not.

thoughts??

thanks
ml




> On Oct 18, 2021, at 6:50 PM, KD7JYK DM09 <kd7jyk at earthlink.net> wrote:
> 
> Like you said, someone may already know, if you hear it, someone else may hear it.  If so, that's awesome.  If not...
> 
> Lets start with exact frequency (ies), or overall range, then reception mode, type of receiver, antenna used, power source, and if wide spread, if possible to what extent, a square mile, 20 square miles, limited to specific areas?  Is it stronger at any particular spot?  Get some recordings to provide to some persons direct as they can't be passed through the list.
> 
> Some will say RFI can't be ID'd by description, or sound, but those that have been around, or even just heard a few types, can do just that, as most RFI is unique to a large extent. A switching mode supply is unique, the model number of consumer garbage it's installed in isn't, but nobody will ever confuse it with the ignition system in a car, or even a power line or wireless weather station, so a thirty second recording can rule out literally billions of RFI sources across the US.
> 
> It may be local to you, may even be your own receiver, or power source, or what you're using to move around to hear the signal all over the place.  Have you heard the signal on foot, with a battery powered receiver, away from everything?  To rule out a receiver, have you heard it to the same extent with an entirely different receiver and different power source?
> 
> Do you have any other electronics on your person at the time?  I've heard mobile phones, WiFi, Bluetooth, digital cameras, MP3 players, near-field devices, like contactless payment devices, and transponders, the type of stuff a person may normally carry.  Even a digital recorder I used to use wiped out a large frequency range from HF to UHF, so I use an analog cassette recorder to document RFI.
> 
> You did mention 440.  Any chance you are listening around 433/434 MHz? If so, there is an ISDM (industrial, scientific, data, medical) band there, and you will hear noise/telemetry, pretty much everywhere around those frequencies, pretty much anywhere in the US.  The devices are supposedly limited to 300', but I hear them miles from the source, even so far out in the desert, or hills, sources can't be seen.
> 
> Any radar installations in your region?  440 is also a military radar frequency range, and I sometimes get blasted.  The PAVE/PAWS system on the west coast, for example, operates from 420-450 MHz, and wipes out individuals, repeater, links, you name it, and I even hear it direct a few hundred miles east of it on occasion.  From the late 80's to late 90's, 420-430 MHz in southern california was often affected by several radar systems.
> 
> Any extra information can help.
> 
> Kurt