Hi Jon, thanks for your input. So I guess the antenna pattern is simply
the spacing of the antennas and the phase you dial in, but you would need
the antennas aligned so the null was in the correct direction?
73 and HNY Kenny K2KW
On Wed, Dec 27, 2023 at 10:35 AM Jon Zaimes, AA1K <jz73@verizon.net> wrote:
> I use NCC-1 and NCC-2 boxes for phasing numerous receive antennas, mostly
> on 160. My property is heavily wooded, with antennas among loblolly pines,
> oak, maple, gum, etc.
>
> For in-band listening while transmitting on 160, I have a pair of 34-foot
> verticals (self-supporting aluminum elements) placed about 1000 feet from
> my nearest transmit array, roughly on a line toward Europe (the RX antennas
> are closer to Europe). Spacing is 1/4 wave. To get maximum end-fire null,
> they are lined up on a heading of 29 degrees. The beamwidth is broad enough
> to hear many Eu signals while transmitting. Equal RG6 feedlines run to an
> NCC-1 in the shack, and I am able to listen within a few kHz of my transmit
> signals
>
> The quality of the transmitter signal and the receiver are major factors
> allowing in-band listening. There was a quantum leap years ago when I
> upgraded my K3's to the newer synthesizer boards (or a K3S).
>
> When I change directions of the transmit array, I usually have to tweak
> the null on the NCC-1.
>
> I also have used a broadside/endfire set of 560-ft Beverages that have the
> TX array off the rear for in-band listening and their null is deep enough
> for this to work. I use an NCC-1 to phase the two pairs of Beverages. The
> closest feedpoint is about 550 feet from the nearest TX array.
>
> I have two sets of broadside-endfire short verticals (four 34-foot wire
> elements hung from trees). These have the two forward and rearward element
> feedlines coming together at tees (no matching) and then separate feeds run
> to an NCC-2 in the shack. Performance of these can equal or exceed that of
> the numerous phased Beverages we have.
>
> A few of my stagger-phased Beverages have separate feedlines going to an
> NCC-1. This allows adjusting the rearward null for optimum.
>
> While the exact phase setting isn't known, the settings achieved
> experimentally are repeatable. I use several BC stations in the 1600-1700
> range for reference.; An S-9 plus signal often will drop out entirely when
> I reverse the phase on the NCC-1 (or -2).
>
> The charts of phased arrays in the ARRL Antenna Book and ON4UN's Low Band
> antennas book are useful in positioning of the various arrays for placing
> the null in a desired direction.
>
> 73/Jon
>
> Jon P. Zaimes, AA1K
> Tower climber for hire
> Felton, Delaware
> http://www.aa1k.us/
>
>
> Reviews of AA1K tower work on eham website:
> http://www.eham.net/reviews/detail/12922
>
> Hug your favorite tower every day, and always stay connected to it.
>
> On Saturday, December 16, 2023 at 10:05:41 PM EST, Kenny Silverman <
> kenny.k2kw@gmail.com> wrote:
>
>
> Rick, my application is for an in-band RX antenna, but on a higher band. I
> just thought the guys here might know more about the NCC-2, MFJ or QRM
> eliminator than most others.
>
> One thought was to create a 2 ele phased vertical array for the RX antenna
> with a known pattern and put the null towards the TX array, along with
> physical separation to allow in-band receiving.
>
> But I was thinking an adjustable phasing system may produce a better null.
> But I wouldn’t want the adjustable unit to create a clover leaf pattern
> for
> example. One null might take out the interference but another null towards
> the desired receiving direction might be created and is not desired.
>
> I hope I’m explaining this well.
>
> Regards , Kenny K2KW
>
> > On Dec 16, 2023, at 9:47 PM, Rick Kunath <k9ao@yahoo.com> wrote:
> >
> > What's your application Kenny and what would you be feeding the antenna
> > output of the phaser into?
> >
> > Rick Kunath, K9AO
> >
>
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