Topband: Compact magnetic loop

[Bill Cromwell]

Hi,

That small mag-loop has a small aperture and so all of the signals 
delivered to your radio will be lower levels than from a  bigger antenna 
(in terms of wavelength. A preamp should improve the signal strength but 
not improve the SNR over what you get with the loop and no preamp. The 
mag-loop reduces the noise with it's high Q and decreased bandwidth and 
those nulls contribute to reduced noise, too. I have excellent luck with 
mine but there just isn't any silver bullet. The mag loop I use on 160 
meters is four and a half feet in diameter. The receiver I use on 160 is 
easily overloaded without some attenuation so the reduced signal levels 
from the mag-loop are *ideal*.

73,

Bill  KU8H

On 01/17/2015 05:06 PM, Ignacy Misztal wrote:
> I homebrewed a magnetic loop for diversity reception with Hi-Z 3 el. in
> K3.  For perhaps up to 1000 miles the loop provides excellent separation
> between signals from Hi-Z. But it hears distant stations poorly, much worse
> than TX inv L. Based on earlier reports I expected the loop to be very good
> for DX.
>
> The loop is made from coax, is tuned and has a transformer.  About 50 KHz
> 2:1 BW. A low-noise preamp does not improve S/N.
>
> Any experiences with the loop here?
>
> Ignacy, NO9E
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