Dave,
When one only really need *one number* (the spacing between
the carriers that one is observing ) we've actually taken a bit of
a step back.
The question to be asked when observing un-ID'd spectra is:
a) Is it continuous spectra or is it discrete 'tones'?
b) What is the width if discrete?
c) What is the spacing if discrete?
A quick 'spin of the dial' used to 'tell' is these factors in the 'daze'
before SDR. In fact, before SDR we still had HP/Agilent/Keysight
spectrum analyzers AND audio spectrum analyzers and
waterfall displays via our PCs.
I still 'spin the dial' on the bandscope-equipped Icoms to come up
with a number for the spacing between observed noise 'tones' too.
73 de AA5CT Jim
.
.
On Friday, February 21, 2020, 7:21:01 AM GMT-6, Dave Cole <dave@nk7z.net>
wrote:
How much simpler SDR has made this sort of thing...
73, and thanks,
Dave (NK7Z)
https://www.nk7z.net
ARRL Volunteer Examiner
ARRL Technical Specialist
ARRL Asst. Director, NW Division, Technical Resources
On 2/21/20 5:10 AM, AA5CT via RFI wrote:
>
> In the "olde days", Jim, we would tune across the band
> and note any similar buzzes at xx kHz apart IF indeed we
> could find any more 'buzzes'. With powerline arcs,
> the spectra is continuous, there are no discrete 'buzzes'
> every xx kHz as with a switching power supply working
> at say 48 kHz. Anyway, once this short search is done,
> a mental picture (in the mind) is assembled, which can
> then be passed along to others using words in print.
>
> 73 de AA5CT Jim
>
> .
> .
>
>
> On Thursday, February 20, 2020, 10:48:09 PM GMT-6, Jim Brown
> <jim@audiosystemsgroup.com> wrote:
>
>
>
> On 2/20/2020 6:04 PM, qrv@kd4e.com wrote:
>> Anyone have a guess as to the source of this noise?
>
> The most useful "picture" of RF noise is a spectrum and waterfall, at
> least 200 kHz wide. Wider views can also be quite useful. Study NK7Z's
> website.
>
> 73, Jim K9YC
>
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