Re: Topband: NCC-2 antenna pattern?

[Pete Smith N4ZR <pete.n4zr@gmail.com>]

If you can get that close I suggest a small explosive charge

73, Pete N4ZR

On 12/17/2023 10:31 AM, John Kaufmann via Topband wrote:
> If you are going to use the NCC-2 to null a nearby in-band transmitter, I think 
> it's very likely that the NCC-2 will get overloaded by the extremely strong RF 
> and not be usable.  I've tried this before and found that to be the case.  In 
> fact, I designed my own totally passive nuller to get around this problem.  It 
> worked and was able to create very deep nulls on an in-band transmitter, but 
> turned out to be very impractical because it required constant adjustment to 
> maintain a null as antennas were changed or rotated.
>
> The other thing to consider is that if the interference is coming from the same 
> direction as a signal you want to hear, nulling the interference will also null 
> the signal. Nulling works best when the interference comes from a very 
> different direction than the signal.  It also helps greatly if the interference 
> sensing antenna receives the interference much more strongly than the main 
> antenna.  This can be done by placing the sensing antenna close to the 
> interference source, if that's possible.
>
> 73, John W1FV
>
> -----Original Message-----
> From: Topband<topband-bounces+john.kaufmann=verizon.net@contesting.com>  On 
> Behalf Of Kenny Silverman
> Sent: Saturday, December 16, 2023 10:05 PM
> To: Rick Kunath<k9ao@yahoo.com>
> Cc: topband<topband@contesting.com>
> Subject: Re: Topband: NCC-2 antenna pattern?
>
> 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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