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From: John Rabson <john.rabson07@gmail.com>
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Date: Tue, 3 Nov 2015 21:08:11 +0100
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To: rsgb_lf_group@blacksheep.org
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Subject: Re: LF: Ferrite Rods For LF Preamplifiers
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I haven’t looked at this sort of configuration recently, but it is worth perhaps consulting the doctoral thesis of David Gibson, which you can find at http://etheses.whiterose.ac.uk/4169/1/uk_bl_ethos_270894.pdf

Chapter 4 contains discussion of antennas, both in air-cored and ferrite-based. Although it principally deals with subterranean situations you may find it useful.

John F5VLF G3PAI

> On 03 Nov 2015, at 20:43, LineOne <dhchurch@lineone.net> wrote:
> 
> Amongst some ferrite rods, I have 3 identical, all with LW & MW windings. I could remove the windings and make a fat bundle of the 3 then wind another coil for an LF preamplifier to improve on my existing one. Inductors are better not to be long and thin I know but what about the magnetic cores such as ferrite?
> This makes some sense, but I would rather join the rods in line, retaining a litz wire LW winding which will tune with about 470pF, ending up with an 18mm PVC tube of about 600mm and a small ABS box in the centre so the whole looks like a VHF dipole.
> Has anyone done this?
> 
> Yesterday we were enveloped in a very wet, dripping fog and it seemed to attenuate my few LF transmissions as nobody received them. UHF TV disappeared later in the evening too.
> The antenna is surrounded by about 100 trees which probably doesn't help. GW4NOS was on, in S. Wales I think they had a nice, sunny day and G3XIZ also.
> 
> Hugh, M0DSZ
> 

john.rabson07@gmail.com

Researching history of RABSON, BLACKSHAW, GAUNTLETT, VERLANDER and ROBSONNE