Re: [IRCA] 4 Foot Box Loop Plans

[Russ Edmunds <wb2bjh@xxxxxxxxx>]

--- On Fri, 1/9/09, Nick Hall-Patch <nhp@xxxxxxxx> wrote:

> From: Nick Hall-Patch <nhp@xxxxxxxx>
> Subject: Re: [IRCA] 4 Foot Box Loop Plans
> To: wb2bjh@xxxxxxxxx, "Mailing list for the International Radio Club of America" <irca@xxxxxxxxxxxxxxxx>
> Date: Friday, January 9, 2009, 7:27 PM
> At 22:04 1/9/2009, you wrote:
> 
> >In extensive testing performed back in the 1970's,
> it was fairly well determined that a 4' loop would have
> sharper nulls than a comparable 2' or 3' loop. As
> Rick states, a balanced loop - whether directly coupled
> through a pre-amp or inductively coupled via a link coil,
> offers sharper & deeper nulls, as well as a more nearly
> symmetical pattern as compared to an unbalanced loop.
> 
> 
> Was there a reprint or some other record of that testing,
> Russ?
> 
> My present vintage loop (it's Nelson's alt-az
> design)  seems pretty well balanced per direction finding
> accuracy and symmetry, and the nulling is good, but I was
> surprised at how well a Sanserino 2' loop compared in
> nulling when I had them side by side 30+ years ago.  There
> was never a proper record of that comparison however.
> 
> best wishes,
> 
> Nick
> 
> 
> *****************************
> Nick Hall-Patch
> Victoria, BC
> Canada


There was not. It may have been included in what was once the NRC Monographs however those were all destroyed in a fire many years ago. I doubt ( but can't say for certain ) that I retained any of that.

My 2' loop had somewhat shallower nulls, and they were less symmetrical. The converse of that was that the peaks were somewhat less defined also, and in some cases, the peaks on the 4' were almost too narrow.

Also included in the tests was one of the original Worcester Space Magnet SM-2's, which was quite asymmetrical in that the nulls were much better on one side than the other, and that they were often not 180 degrees from each other but sometimes as much as +/- 20 degrees.

I'll have to take a look in one of the file cabinets in the basement over the weekend to be sure.

 


Russ Edmunds
Blue Bell, PA ( 360' ASL )
[15 mi NNW of Philadelphia]
40:08:45N; 75:16:04W, Grid FN20id
<wb2bjh@xxxxxxxxx>
FM: Yamaha T-80 & Onkyo T-450RDS w/ APS9B @15'
AM: Modified Sony ICF 2010 barefoot



      
_______________________________________________
IRCA mailing list
IRCA@xxxxxxxxxxxxxxxx
http://montreal.kotalampi.com/mailman/listinfo/irca

Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers

For more information: http://www.ircaonline.org

To Post a message: irca@xxxxxxxxxxxxxxxx