[Lowfer] Noise Canceler Effectiveness... How it REALLY works

[Scott Tilley]

Hi Bill

I agree!  Imagine the poor chap that some days ago asked what seemed 
like a simple question :-)

My solution to my noise issues is a kludge of many ideas so I can make 
what I have at hand work.   I built the canceler I use simply because it 
presented a solution that could use whatever antennas I connected to 
it.  I have dreamed about a K9AY antenna but at my new QTH I am ground 
challenged and from what I understand the K9AY requires a good ground 
under the 'loops' if that's what they are :-) I have solid bedrock over 
most of my yard...  So this was considered the best compromise and yes a 
solid reason I'm considering an Ashlock loop for LF transmitting antenna 
in the near future, well actually two :-)

As Ed pointed out the canceler works on anything you connect it to as 
long as the signal amplitudes are within the range of the adjustments to 
find the null after the phase setting has been found.  And as you and 
Johan have pointed out connection to a loop allows one to steer a 
Cardiod shaped null.  Very handy to null one's only neighbour who has 
dimmers everywhere...

I have found that the positional stability of the null is very good over 
time and allows me to run my grabber full time even as the neighbour 
dims merrily away. 

I have found my 2200m RX nirvana.  Bring on ZL!

73 Scott





Bill Ashlock wrote:
> Scott,
>  
> Sorry.  I got into to this rather late and read most of the postings 
> on this subject in random order.  I didn't see your original post 
> until I had posted my first. You must feel like you opened up a can of 
> worms?
>  
> Speaking strictly for myself I'm glad your question appeared because I 
> wasn't sure if my understanding of how this works was correct until 
> some reinforcement came through. The working principle for the K9AY is 
> still up for debate but that identifies another one of the beauties of 
> this type of interactive education.
>  
> Bill 
>
>
> ------------------------------------------------------------------------
>
> Date: Wed, 14 Jan 2009 08:52:20 -0700
> From: sthed475 at telus.net
> To: lowfer at mailman.qth.net
> Subject: Re: [Lowfer] Noise Canceler Effectiveness... How it REALLY works
>
>
>  Hi Bill
>  
> Nothing new was claimed.  It was simply a reminder that this type of 
> stuff really works to help someone who asked along time ago in the 
> thread...
>  
> 73 Scott
>  
>  
> On Jan 14, 2009, *ashlockw at hotmail.com* wrote:
>
>
>     Gentlemen:
>      
>     After reading the description of the VK5BR noise cancelling
>     circuit it appears to me this is nothing more than the old trick
>     of combining the figure "8" pattern from a loop antenna
>     and the circular pattern from a long wire antenna to form a
>     cardioid pattern. If the amplitude and phase of these signals are
>     properly adjusted the cardioid can have a noise-reducing null of
>     at least 30db. A separate receiver connected to each antenna could
>     be also used along with the proper amplitude and phasing
>     adjustment to do the same thing. BTW the popular K9AY antenna uses
>     exactly the same principle by introducing a controlled E field
>     distortion to the normal figure "8" pattern that this antenna
>     would normally have.
>      
>     Bill Ashlock    
>
>
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