Re: Reliable but reasonably priced sources of ferrite for FSLs?-FARMERIK


Gary DeBock
 

<<<   Also a question for FSL designers. Has any particular ratio of diameter to ferrite length stood out as being better, and in what way is it better.
For example how might a 12 inch diameter FSL with 4 inch rods compare to a 4 inch diameter FSL with 12 inch rods?   >>>

Richard,

Extensive FSL antenna testing in 2012 revealed how all the variations in coil diameter, ferrite length and ferrite material (rods or bars) play out in the final determination of actual weak signal DXing gain. Seven different FSL test models were constructed and multiple A/B weak signal reception tests were run in order to definitively answer these questions. The result of the experimentation was the FSL antenna "sensitivity formula," which can accurately predict the actual gain of an FSL antenna prior to construction. Full details are in the article posted at     
   
http://www.mediafire.com/file/6oyoldllrbiwf91/FSL_Antenna_Design_Optimization.doc/file

Gary DeBock (in Puyallup, WA, USA)





-----Original Message-----
From: Rik <farmerik@...>
To: main <main@UltralightDX.groups.io>
Sent: Mon, Feb 4, 2019 8:23 am
Subject: [UltralightDX] Reliable but reasonably priced sources of ferrite for FSLs?-FARMERIK

Searching on Ebay, I see lots of Ferrite rods and bars, but very little info on which are suitable for MW frequencies.

Also a question for FSL designers. Has any particular ratio of diameter to ferrite length stood out as being better, and in what way is it better.

For example how might a 12 inch diameter FSL with 4 inch rods compare to a 4 inch diameter FSL with 12 inch rods?

Also, has anyone intertwined the Litz wire over and under ferrite rods the way the 'peg' form for winding air core Diamond and Rook weave coils, but the ferrite stays in place?

-FARMERIK

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