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Date: Sat, 06 Mar 2010 11:35:54 +0100
From: =?ISO-8859-1?Q?Wolfgang_B=FCscher?= <dl4yhf@freenet.de>
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Subject: Re: AW: AW: LF: Re: 9kHz noise level
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Hi Stefan, Paul, and the group;

Nice to hear about the progress, and hope to catch some signals here=20
(one fine day) in JO42FD near Bielefeld.

Stefan, just one suggestion:
A 2 m long 25 cm diameter tube as coil form will tolerate high voltages,=
=20
no doubt. But it's not the optimum L/D ratio for maximum coil 'Q'.
Did you consider other 'plastic objects' like plastic barrels (in=20
German: Die gr=FCnen oder blauen 200-Liter-Regentonnen, die man in vielen=
=20
Baum=E4rkten findet) ?
I have one of those things here, and iirc the material is polyethylene,=20
which is quite a good dielectric.. better than some PVC.
You could even cool it from the inside wall with water, if necessary ;-)

Greetings from snowy Westphalia,
   Wolf  DL4YHF .


Stefan Sch=E4fer schrieb:
> Very nice Paul!
> I hope i can generate a peak outcoming of the noise in the picture ;-)
> Yesterday i have got a PVC tube with 25cm diameter and 2m long. Addition=
ally i have bought 0,4mm diameter enameled copper wire, abt 6km in one pie=
ce (i can give back the rest). So today i try to wind the big L, abt 540mH=
! Than, the internal R will be abt 350 Ohm, not less but no problem. As sa=
id, the limiting factor will be the voltage at the wire...
> =20
> 73, Stefan/DK7FC
>
> ________________________________
>
> Von: owner-rsgb_lf_group@blacksheep.org im Auftrag von Paul Nicholson
> Gesendet: Sa 06.03.2010 08:27
> An: rsgb_lf_group@blacksheep.org
> Betreff: Re: AW: LF: Re: 9kHz noise level
>
>
>
> Stefan wrote:
>  > I plan to transmit on 8,9700 kHz...
>
>  > during the test i make QSY of some Hz if the RXing station
>  > has a carrier/line on this QRG.
>
> Here's a live spectrum for 8970 +/- 1Hz - resolution is 5mH.
> Amplitude calibration is only within a factor of two or so.
>
>   http://abelian.org/vlf/nb.shtml
>
>  > do you know other members in the VLF group who live near
>  > frankfurt?
>
> Ich habe die Frage gestellt.
> --
> Paul Nicholson
> --
>
>
>
>  =20