In the "old" days, we put copper and iron into the modulation transformer.
Some really hefty installations even "modulated" the concrete floor on
which they were mounted. These days, we put who knows what to clean up the
effective SMPS which is repurposed as the modulator without the huge
transformer. And......we all know how dirty any SMPS can be. So, now we
put all that massive copper and iron into filter components to clean up the
effective SPMS, a.k.a., modulator. I'm an old fossil and still prefer the
modulation transformer. However, there are a number of hams in Boulder,
Co. who have their whole AM transmitter at the 500-watt to 1 kW level in a
shoe box (external cooling, of course). Further,.........one can lift it
without straining one's back. I still like the copper and iron
incantations.
Dave - WØLEV
On Thu, Oct 28, 2021 at 1:55 AM Don Kirk <wd8dsb@gmail.com> wrote:
> Hi Gary,
>
> All of the annual measurements appeared to be at the fully licensed daytime
> power level of 5 KW but the station was running much more power than this
> to the surprise of the engineer when we entered the transmitter room and he
> could not understand how this happened. We backed the power level back
> down to 5 KW and the splatter was still present. I suspect the run away
> transmitter (unexpected high power level) was all related to the failure
> that occurred in the transmitter that was also related to the splatter
> issue, but we will never know for sure. All we know is that the pulse
> duration modulator was recapped, the transmitter is back to full daytime
> power level of 5 KW, and the splatter is gone.
>
> 73,
> Don (wd8dsb)
>
> On Wed, Oct 27, 2021 at 11:53 AM Gary Peterson <kzerocx@rap.midco.net>
> wrote:
>
> > Don,
> >
> > This could be one of the rare instances that a sudden change occurred in
> > the radio station’s transmitting system. Rare, but not unheard of.
> >
> > I find it interesting that you mentioned that the station’s output power
> > far exceeded measurements, made 2 weeks prior, during the annual
> > inspection. Is it possible that the station was running at some level of
> > reduced power at the time that the NRSC 2 measurements were performed?
> > Before I measure any AM station, I ensure that the station is operating
> at
> > licensed power. I either talk directly to their engineer, check their
> > remote control readings or actually enter the transmitter building.
> Once,
> > I found an AM station running night power during the day. Apparently, a
> > power bump killed the clock in the remote control system. The UPS
> battery
> > had failed, causing the clock to zero the date and time. This probably
> > happened at night and left the station stalled on night power. Just a
> > couple of months ago, I measured a local AM station that was not in
> > compliance with occupied bandwidth measurements. I checked the same
> > station at night, to see if the problem existed when they should have
> been
> > at night, reduced power. They were at full power, two hours after local
> > sunset. Same situation. Power bump with failed UPS resulting in station
> > staying at full power, 24 hours per day. Who knows how long this had
> been
> > going on.
> >
> > I never cease to be surprised at what I sometimes encounter. My favorite
> > saying about many broadcast stations is that the lights may be on, but
> > nobody’s home.
> >
> > Gary
> > KzeroCX
> >
> >
> > 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)
> > _______________________________________________
> > RFI mailing list
> > RFI@contesting.com
> > http://lists.contesting.com/mailman/listinfo/rfi
> >
> _______________________________________________
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>
--
*Dave - WØLEV*
*Just Let Darwin Work*
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