[Lowfer] Excellent VLF condx this morning!

[jrusgrove at comcast.net]

Mitch

It used to be at 3' but the deer took an interest in it so I moved it up to about 8' AGL. Didn't see 
much difference in signal or noise levels.

As far as the setup here ... it has evolved over a number of years. Eliminating all traces of crud 
and reaching the 'natural' noise floor required a number of different 'fixes'. This is not a 
particularly quiet location thus the following rigamarole.

First, it proved necessary to use battery/solar power to eliminate all power supply noise - no power 
is fed from the shack. A coaxial cable common mode choke (16T FT-240-77) was required directly below 
the e probe to eliminate 19 and 38 kHz 'products' from the 5000 watt FM broadcast station 2000' 
away. This choke does almost nothing at VLF and would not be required if not for the nearby FM 
broadcast station. The e probe has several sloping radials attached to it that also guy the mast. 
Going down the mast, the coaxial cable encounters an isolation transformer/dc injector ( 
http://www.w1vd.com/Eprobedcinjector.pdf ) at ground level where power from solar panel/battery is 
inserted. The only earth connection is at this point as shown in the schematic. From there the 
coaxial cable lays on the ground on it's way to the house. Before entering the house it encounters 
another isolation transformer - same core/winding as in the dc injector. No earth ground is used at 
this point. Routing of the coaxial cable to different locations in the house and to different 
receivers and computer sound cards has no effect on the 'clean' noise floor.

I've also tried shielded twisted pair as feedline to the e probe (like I use to feed the large K9AY) 
but there was no advantage over the coaxial cable.

Jay




----- Original Message ----- 
From: "Mitch Powell" <mitch.powell at sympatico.ca>
To: "Discussion of the Lowfer (US, European, &amp;UK) and MedFer bands" <lowfer at mailman.qth.net>
Sent: Sunday, September 18, 2011 2:55 PM
Subject: Re: [Lowfer] Excellent VLF condx this morning!


> Hi Jay:
> At what height is the Amrad ?
> Assuming you feed with coax - do you ground the coax at the base of the support ( vertical 
> portion ) ?
>
> The base of mine is at 15 feet - with the coax grounded as it enters the ground.
>
> Sounds like Dex is setting up for Frankenstein III ?
>
> Mitch
>
>
>
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