Message-ID: <58F5FFFD.1020903@posteo.de>
Date: Tue, 18 Apr 2017 14:01:01 +0200
From: DK7FC <selberdenken@posteo.de>
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3
MIME-Version: 1.0
To: rsgb_lf_group@blacksheep.org
References: <58F5E1F9.9060.92EC4E@roelof.ndb.demon.nl>
In-Reply-To: <58F5E1F9.9060.92EC4E@roelof.ndb.demon.nl>
Subject: Re: LF: Staic Rain
Content-Type: multipart/alternative;
 boundary="------------010404090801020409060905"
Sender: owner-rsgb_lf_group@blacksheep.org
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org
Status: O

This is a multi-part message in MIME format.
--------------010404090801020409060905
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit

Hi Roelof,

Hmmm, i would say it is the frequency response of the front end of the 
antenna. The input frequency spectrum is that of a discharge of a 
charged rain drop through the RC network on the input. Maybe protection 
diodes could help here, a bit. They could become conductive and lead the 
biggest part of the charge towards GND.
On the other side your probe is protected against direct water contact, 
so no galvanic connection. Anyway there is an electric field building up 
arround the probe when a charged drop is falling on the wet tube arround 
the antenna and there is a dynamic current flow against ground, so it 
will have a frequency spectrum that you seem to observe...

73, Stefan

Am 18.04.2017 11:52, schrieb Roelof Bakker:
> Hello all,
>
> Last night reception on 630m was severely effected by static rain.
> See attachment.
>
> I have often noted that the effect of static rain is worse for>  450
> kHz and that it is almost completely gone below 300 kHz.
>
> Does anyone have an explanation for this phenomenon?
>
> 73,
> Roelof, pa0rdt
>    
>
>
> The following section of this message contains a file attachment
> prepared for transmission using the Internet MIME message format.
> If you are using Pegasus Mail, or any other MIME-compliant system,
> you should be able to save it or view it from within your mailer.
> If you cannot, please ask your system administrator for assistance.
>
>     ---- File information -----------
>       File:  Static Rain.jpg
>       Date:  18 Apr 2017, 11:45
>       Size:  71165 bytes.
>       Type:  JPEG-image
>    

--------------010404090801020409060905
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
  <meta content="text/html; charset=ISO-8859-1"
 http-equiv="Content-Type">
</head>
<body bgcolor="#ffffff" text="#000000">
Hi Roelof, <br>
<br>
Hmmm, i would say it is the frequency response of the front end of the
antenna. The input frequency spectrum is that of a discharge of a
charged rain drop through the RC network on the input. Maybe protection
diodes could help here, a bit. They could become conductive and lead
the biggest part of the charge towards GND. <br>
On the other side your probe is protected against direct water contact,
so no galvanic connection. Anyway there is an electric field building
up arround the probe when a charged drop is falling on the wet tube
arround the antenna and there is a dynamic current flow against ground,
so it will have a frequency spectrum that you seem to observe...<br>
<br>
73, Stefan<br>
<br>
Am 18.04.2017 11:52, schrieb Roelof Bakker:
<blockquote cite="mid:58F5E1F9.9060.92EC4E@roelof.ndb.demon.nl"
 type="cite">
  <pre wrap="">Hello all,

Last night reception on 630m was severely effected by static rain.
See attachment.

I have often noted that the effect of static rain is worse for &gt; 450 
kHz and that it is almost completely gone below 300 kHz.

Does anyone have an explanation for this phenomenon?

73,
Roelof, pa0rdt
  </pre>
  <pre wrap="">
<fieldset class="mimeAttachmentHeader"></fieldset>
The following section of this message contains a file attachment
prepared for transmission using the Internet MIME message format.
If you are using Pegasus Mail, or any other MIME-compliant system,
you should be able to save it or view it from within your mailer.
If you cannot, please ask your system administrator for assistance.

   ---- File information -----------
     File:  Static Rain.jpg
     Date:  18 Apr 2017, 11:45
     Size:  71165 bytes.
     Type:  JPEG-image
  </pre>
</blockquote>
</body>
</html>

--------------010404090801020409060905--