Long ago (in the early 1970's) and far away in Corona, California, I had a
similar problem with a local rather low-budget station. The splatter was
evident as high as 40-meters and "rather" nasty on 160. This was well
before the days of PWM AM modulation systems. The problem turned out to be
a number of loose and rusty (and neglected) guy wires, most touching
something or "everything" else in the vicinity of the tower and only
loosely connected to the metallic tower. DDdaaaaahhhhhhhhh................
Dave - WØLEV
On Mon, Oct 25, 2021 at 6:47 PM Don Kirk <wd8dsb@gmail.com> wrote:
> Late last year I stumbled upon a sick AM radio broadcast station in
> Indianapolis (WNTS, 1590 KHz) while driving to a hams QTH to track down
> some powerline noise. The station was generating splatter all the way up
> into the 160 meter band which was causing problems on 160 meters at Mike's
> (W9RE) QTH.
>
> The AM radio station's Chief Engineer invited me to the transmitter site to
> work with him and a contract RF Broadcast Engineer on the problem (both of
> them are hams). The problem turned out to be bad capacitors in the "Pulse
> Duration Modulator" which is really a pulse width modulation (PWM) system.
> It took almost 10 months for the replacement capacitors to arrive and for
> the repairs to be completed. The transmitter was finally fixed earlier
> this month, and in the meantime the transmitter was running at reduced
> power to limit the splatter.
>
> Today I created a simple website to document the case, and here is a link
> to the website for those interested:
> https://sites.google.com/view/wnts-rfi/home
>
> Here is a link to a youtube video recording the splatter when I originally
> stumbled upon it and this link is also on my website mentioned above:
> https://youtu.be/VaunFwVAyUI
>
> Just FYI, and 73.
> Don (wd8dsb)
> _______________________________________________
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> RFI@contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi
>
--
*Dave - WØLEV*
*Just Let Darwin Work*
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