Topband: Compact magnetic loop

[Arthur Delibert]

I've been playing with an amplified Wellbrook ALA 1530S+ loop antenna for about 10 days now.  It does a very good job on both close-in and long-distance signals across the SW spectrum, and its ability to knock down the local noise is a great benefit in my dense suburban location.  

Compared to my two pennant antennas, which have DX Engineering amplifiers, both my ears and my display tell me that the Wellbrook signal is a few dB lower, although the better S/N ratio often makes the signal more readable on the Wellbrook.  The difference in signal level is not surprising, given the larger size of the pennants; in fact, the surprising thing is that the difference isn't greater.

Given my age and the continual loss of tall trees on the property, it's clear that I'm going to need a replacement for the pennants someday that doesn't require trees or ladder-climbing.  The Wellbrook may be it.

Art Delibert, KB3FJO

> Date: Sat, 17 Jan 2015 17:06:33 -0500
> From: no9e at arrl.net
> To: topband at contesting.com
> Subject: Topband: Compact magnetic loop
> 
> 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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