Re: [IRCA] Cape Perpetua, Oregon Cliffside DXing - Sept. 9th

[Steve Ratzlaff <ratzlaffsteve@xxxxxxxxx>]

Thanks for the very interesting report on the untuned FSL and preamp. 
You didn't say but apparently you parked so the FSL was peaked/pointed 
for maximum pickup toward the North Pacific. You might have had better 
DU reception if it had been pointed the DU direction. Looking at your 
pictures, your transformer would work better as a broadband transformer 
if the windings were overlapping instead of side by side. The impedance 
matching transformer articles by Nick Hall-Patch and John Bryant at 
dxing.info explain this. I've done my own tests and overlapping windings 
always work better for broadband toroid transformers. (It's possible the 
small impedance transformation doesn't do much too, but it probably 
doesn't hurt much either, if at all.)
73 and hope you continue to have good coastal vacation DXing.
Steve
NE Oregon

On 9/10/2012 6:00 PM, Guy Atkins wrote:
> Yesterday morning before sunrise I sought out the Cape Perpetua, Oregon
> cliff that has served Gary DeBock so well with a flood of DU DX with his
> Ferrite Sleeve Loop (FSL) antenna.
>
> With Gary's encouragement and supply of a regular tuned FSL, and Chuck
> Hutton's help with electrical formulas and initial impedance measurements,
> I was able to convert the FSL into a broadband (non-tuned) loop for
> capturing the entire band with Perseus SDR recordins. The antenna
> accompanied me to Oregon, secured inside a container strapped to the roof
> of our family's vacation vehicle.
>
> The 7-inch FSL was converted to broadband use by the removal of the tuning
> capacitor and the addition of a homebrew 1.6 to 1 turns ratio transformer
> and a Wellbrook FLG100LN amplified Flag antenna module. (FSL >> 26/15 turns
> on Amidon FT140A-J core >> input of FLG100LN >> receiver. Chuck calculated
> the FSL's impedance as 3K ohms at 1.7 MHz; the Wellbrook's input impedance
> is 1200 ohms.)
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