>> On 2/1/2023 4:52 AM, K9MA wrote:
>>> Besides the preponderance of 120 Hz harmonics in the AM audio, the
>>> very broadband nature of line noise is usually the main indicator.
>>
>> 120 Hz is also a strong component of electronic noise generated by
>> power supplies and power control equipment. The audio spectrum is not
>> a great clue -- the RF/IF waterfall shows where the bodies are buried.
>>
>> 73, Jim K9YC
>> _______________________________________________
>>
> That's true, but I have never seen broadband noise with 120 Hz harmonics
> in the AM audio which was NOT power line noise. And, alas, I've seen a
> lot of line noise.
>
> 73,
>
> Scott K9MA
I have an LED fixture for you that produces 120 Hz buzz over decades of
bandwidth, nearly indistinguishable from an arcing power line: The Elite RL675.
Twenty-one of these, installed next door, resulted in a 1.5 year shootout
including ARRL and the FCC and even after mitigation left my home station
permanently QRT. Yes, it can be that bad... Full story is on my RFI page. Here
are detailed measurements on said fixture:
https://na6o.com/main/RFI_files/Elite%20RL675%20RFI%20Test%20Report.pdf
<https://na6o.com/main/RFI_files/Elite%20RL675%20RFI%20Test%20Report.pdf>
73,
Gary NA6O
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
|