[Premium-Rx] Super ferrite rod aerials

[John Reed]

----- Original Message ----- 
From: "Warren Ziegler" <ny2h at yahoo.com>
To: "John Reed" <jreed at alum.mit.edu>; "Premium RX" 
<premium-rx at ml.skirrow.org>
Sent: Wednesday, August 03, 2005 11:36 AM
Subject: Re: [Premium-Rx] Super ferrite rod aerials


We tested a bunch of different ferrite loops with the 16' included several 
years ago.  There was also one air core loop, a Kiwa medium wave loop 
rewound with Litz wire to tune  LF.  The diameter of this loop was 12".  It 
compared favorably with all the big ferrite loops on our tests which 
involved nulling ability and signal strength.  I still have the Kiwa loop. 
In comparisons with my 30" ferrite loop, the ferrite is a little better on 
LF.  It seems to be less noisy on very weak signals.   I expect on medium 
wave they would be very close.  Ferrite starts to lose sensitivity around 1 
MHz.  This difference could also be due to different tuning methods.  The 
air core loop tunes with voltage variable capacitors, and the ferrite with 
air varaible capacitor.  At times I can hear MW signals overloading the 
tuning diodes on the air loop and this may indicate overload causing a 
higher noise level overall.

John

>
>    Did the 16' or even the 4' ferrite loop have any
> advantage over an equivalent diameter (4' or 16'
> circular or square) air core loop?
> 73 Warren K2ORS/WD2XGJ
>