Topband: Using shielded CAT5 data cable as feedline for active antenna; benefits of multi-turn K9AY loop/SAL/etc?

Pete Smith N4ZR n4zr at
Sat Jan 2 10:45:43 EST 2016

I was recently reading a web page by LZ1AQ 
<>.  It is full of fascinating data and 
design equations for the use of small magnetic loop antennas.  There 
were two points, in particular, that caught my layman's attention:

1.  He recommends using shielded CAT5 data cable with RJ-45 connectors 
as feedline.  The obvious advantage is having three pairs left over for 
voltage supply and control.  See 
<> for more information.

2.  He cites experimental data showing that coplanar crossed loops and 
multi-turn quad loops both offer very significant improvement in the 
recovered signalcompared with a single loop.  See 
<> to 
check whether I got this right. Anyway, it occurred to me to ask if 
anyone has ever tried multiturn K9AY, SAL or flag/pennant receiving 
antennas, and did you see something similar?

Any other critiques of his design would be appreciated.  The price is 
certainly right, and the construction looks good. A couple of 1-meter 
coplanar loops wouldn't be at all hard to construct.


73, Pete N4ZR
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