[600MRG] My local noise - more info...

[John Langridge]

yes but you have to change out the HPF for a LPF.  There are several mods available for that box.  It can actually work down to 100 KHz.

John XIQ




________________________________
 From: Carl <km1h at jeremy.mv.com>
To: kgordon2006 at frontier.com; John Langridge <jlangridge at sbcglobal.net>; 600m group <600mrg at w7ekb.com> 
Sent: Sunday, September 22, 2013 3:57 PM
Subject: Re: [600MRG] My local noise - more info...
 

Does the MFJ work at 600M?

Ive heard it is excellent for 160.

Carl
KM1H


----- Original Message ----- From: "Kenneth G. Gordon" <kgordon2006 at frontier.com>
To: "John Langridge" <jlangridge at sbcglobal.net>; "600m group" <600mrg at w7ekb.com>
Sent: Sunday, September 22, 2013 4:17 PM
Subject: Re: [600MRG] My local noise - more info...


On 22 Sep 2013 at 11:56, John Langridge wrote:

> >I have seen tests of others, like MFJ's, on youtube. Some work very
> >well, others don't.
> 
> I've seen some of these tested and implemented correctly and
> incorrectly in the past. The circuits are not rocket science so I
> think more often than not the problems that exist involve 1) loss of a
> proper "noise" antenna that can actually hear the noise in question -
> it has to be able to do this if it is to phase it out and 2) the noise
> can't be in the direction that the noise antenna resides with respect
> to the main antenna.

Ah! I had never considered this...thank you for the information...and it makes
sense too.

> These seem to work pretty well from what I have
> seen and have considered one here recently as the noise floor appears
> to be headed upward. I think most recently KL7L was using one in
> conjunction with his K9AY loop to manage the noise from the electric
> fence, IIRC.

Oh. That makes sense too.

Well, I am going to have to "revisit" those units. I have always thought that
the principle should be workable.

FYI, the early models of the U.S. Army BC-312/342 receiver had a
manually-adjusted, passive version of this principle, but since most operators
really never learned how to properly use it, it was removed from all
subsequent models.

Ken W7EKB

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