Hi Stefan, Paul, and the group;
Nice to hear about the progress, and hope to catch some signals here
(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,
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
German: Die grünen oder blauen 200-Liter-Regentonnen, die man in vielen
Baumärkten findet) ?
I have one of those things here, and iirc the material is polyethylene,
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 Schäfer 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. Additionally i
have bought 0,4mm diameter enameled copper wire, abt 6km in one piece (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 said, the limiting
factor will be the voltage at the wire...
73, Stefan/DK7FC
________________________________
Von: [email protected] im Auftrag von Paul Nicholson
Gesendet: Sa 06.03.2010 08:27
An: [email protected]
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
--
|
