Return to KLUBNL.PL main page

[Top] [All Lists]

Re: LF: ELF communications ?

To: [email protected]
Subject: Re: LF: ELF communications ?
From: DK7FC <[email protected]>
Date: Mon, 01 Dec 2014 21:32:42 +0100
Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20120113; h=from:message-id:date:user-agent:mime-version:to:subject:references :in-reply-to:content-type:content-transfer-encoding; bh=CCloo4ZlaahWwMjaqwyYYL0487ZYDMR6NsrmhB3Mpc4=; b=z7GmyXy0DDFRt/mDaYl49XN97p0hDD0MOUDRsc3EYk4r7p3rVEwAHpekcJ50f+6Pe2 ZPS5d5XkcNDiSJqfLNpUVeVLZ6VRrGJ6n0kw4qFPP+Znh4ZX9stalK8g847vYdIq27WT 1j7I0fB/AQZNJuzVTqwFaDxo7WMVx+STMCut5q1OTQ2tZNWQDo8FC4tmqvC5maTrvucs xKgTFBKn2fer5+gqTX+Y1a4YS4H3MoKTwVz9vk+qbdFLQ4YS2zX6ulcpnEkrCs7jLwiH oN1YKfkEFjKMLMLGBAgYxebUqG5mbDdx8oH9BTKffT/0xpDxhxJ3JGirOE/JDPZHKlrx kmUQ==
In-reply-to: <[email protected]om>
References: <[email protected]> <[email protected]om>
Reply-to: [email protected]
Sender: [email protected]
User-agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv: Gecko/20100227 Thunderbird/3.0.3
Hi Dimitris,

Well, i have had 2 of these HV transformers. The first one got an internal fault during the experiments. A few weeks later i took the second one and wanted to repeat the experiment but i found that it was shorted from the beginning on. BUT, last friday we bought another HV transformer of a similar type for an application at work. This one even generates 18 kV and 40 mA! I will repeat the experiment then.
Regarding VLF, i do not think that one can get 100% or even 30% of the
rated voltage at frequencies above a few 100 Hz. The stray-C of the
secondary turns is much to high. Also the core of the transformer will
not work at a few kHz. For a 10 kV transformer i would guess and expect
5 kV at 500 Hz when using a high resistive load.
But just give it a try.

Aaah, i understand, it is summer in VK and you want to go out in the field, trying a ground dipole, 2x 10 km? :-)
73, Stefan/DK7FC

Am 01.12.2014 21:19, schrieb Dimitrios Tsifakis:
Hi Stefan,

This afternoon i'm attempting to transmit on my INV-L on 136.172 Hz (not
kHz!). Just preparing my H bridge VLF PA and i intend to use an old 10 kV
transformer which i got from an old furnance (to inflame the oil stream),
Have you done any more tests with this? I am curious to see the
results. Would this idea work on VLF as well? I have come across some
power toroid transformers that have a reasonablywide useful bandwidth
that extends in the VLF part of the spectrum and perhaps such a
transformer connected to a really nice amateur LF/MF antenna could be
a very quick way of getting a small signal on VLF?

73, DImitris VK1SV

<Prev in Thread] Current Thread [Next in Thread>