Topband: K3 & some interesting noise lessons in the ARRL 160.

[Guy Olinger K2AV]

>>I am confused about "1831.5 being occupied."

That's 1831 was UNoccupied, so I used it as a run frequency. No one else
was using it as a run frequency.

The noise blanker, at that time, with aforementioned settings, was
producing a very effective null in the noise at 1831-1833.  There were
vacant frequencies in that range, vacant at various times, and I used them,
in the process breaking the dx window rule.

The combination of NB settings and the 250 Hz width (with 250 8 pole
filter) on the K3 was NOT being falsed by nearby frequencies, nor was it
"mushing" the noise over weak signals, that discovered by a few hours
messing with settings.

If I turned OFF the K3 NB, the buzz noise at 1831-1833 drowned out all but
loud signals.

Tonight the noise null using the NB on the TX antenna is around 1826. On
the TX antenna the noise goes up over 16 dB when I turn the NB off. On the
RX ant the null is at 1838 and the noise goes up 17 dB when I turn NB off.
These are less pronounced than on the contest night when the diffs were in
the low 20's, and the noise was S9.

73, Guy


> 1.  The NB works well on the noise, but gets falsed by nearby
> signals on a crowded band in the contest.  IOW, the NB
> would have worked fine during non-contest times.  The NB
> on my FT-1000 is like this (I have the W8JI NB mod).
>
> or
>
> 2.  The local noise was lower on 1831.5, but you still needed
> the NB.  QRM from other stations was not an issue.
>
> I don't own a K3, but an considering buying one.
>
> Rick N6RK
>