[RFI] Splatter from AM Radio Station WNTS Indianapolis

[Don Kirk]

Hi Gary,

Funny that you bring this up (annual inspection).  It just so happens that
WNTS had just gone through their annual inspection (measurements) 2 weeks
prior to the splatter showing up and I saw the paper work documenting the
inspection, and I know for a fact that I could not hear the splatter 10
days prior to the splatter occurring when I was down in the area of the
transmitter site and when I heard the splatter 10 days later it was very
strong.  We also noticed something odd when I went to the transmitter site
with their engineers to determine the problem as the transmitter output
power far exceeded the measurements that were made 2 weeks prior during the
annual inspection so it did indeed appear the issue was not a gradual
issue, but more of a sudden failure.

Just FYI,
Don (wd8dsb)

On Wed, Oct 27, 2021 at 9:31 AM Gary Peterson <kzerocx at rap.midco.net> wrote:

> Hams should seldom have to suffer harmonics or spurious emissions from AM
> broadcast stations.
>
> Every AM broadcast station is required to perform annual measurements,
> searching for these types of problems.  I contract to perform spectral
> measurements for most of the AM stations within a 100 mile radius of my
> home.  I have the necessary equipment and travel to within approximately 1
> kilometer of each transmitter site.  I measure each station’s occupied
> bandwidth, measure harmonics, up through and including the 6th and search
> for spurious signals, below, in and above the broadcast band.  Each station
> receives a written report, including data and graphs.  The station is
> required to retain these reports for a period of two years.  Measurements
> must be performed annually, with no more than 14 months elapsed between
> successive ones.  See 73.44 and 73.1590.
>
> My experience indicates that it is rare for an undesired emission to
> suddenly appear.  These types of errant signals, almost always, occur
> gradually.  I keep copies of my reports and always compare any new report
> with the previous one.  I have notified stations that their spectral purity
> is gradually deteriorating.  This may be a sign of failing electrolytic
> capacitors.  Notification of an impending problem allows the station to
> make corrections, before falling out of compliance with FCC regulations.
>
> If you encounter a problem with an AM station, you might ask if you could
> see their last two NRSC 2 measurements.  If there’s a problem, it is
> possible that these measurements have not been done for several years.  If
> you are being stonewalled, file a complaint with the FCC.  Don’t hold your
> breath for a response, however.  The field enforcement division was almost
> eliminated, several years ago.
>
> I agree with Rob, in that many AM stations have acquired translators on
> the FM broadcast band.  Regulations, with some exceptions, require that the
> parent AM station remain on the air, in order for the FM translator to
> exist.  In many instances, management and programming have determined that
> the FM signal is the only one that is marketed or valued.  I am aware of AM
> stations that are only mentioned in the required, top hour ID.  Otherwise,
> all one hears is the FM frequency being promoted.  This is a strong
> indicator that the AM transmitter plant may be the victim of benign
> neglect.  Many of these stations do not have anyone on staff with technical
> competence.  In a crisis, a contract engineer will be called in to put out
> the fire.  However, this is no excuse for violating the rules and
> regulations.
>
> Gary Peterson
> KzeroCX
> Rapid City, SD
>
>
>
> ...stations should budget for maintenance like
> this.  It's a management problem.  A lot of what's really going on
> with an AM like this is revealed here:
>
> WNTS-AM also broadcasts its primary channel from this additional
> transmitter
> W280FR 103.9 FM Beech Grove, IN (99 watts)
>
> In other words, the AM has a LPFM and nowadays, that's the signal that
> matters to management.  In a lot of cases like this, the AM is only on
> because it justifies the license for the FM.  A lot of licensees with
> LPFMs simulcasting, let the AM go because they think no one listens to
> it; in this case the class D FM covers most of metropolitan
> Indianapolis.  That's where the license value is, plus the AM DA real
> estate.   I'm not criticising the station engineer, but years ago,
> this would have been caught a lot sooner without a ham having to
> complain about it.
> Rob K5UJ
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