Message-ID: <58F60567.20001@posteo.de>
Date: Tue, 18 Apr 2017 14:24:07 +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: <15b72b3360e.marcocadeddu@tin.it> <731997437.20170416124847@gmail.com> <58F525B4.9090008@posteo.de> <1229336941.20170418125840@gmail.com>
In-Reply-To: <1229336941.20170418125840@gmail.com>
Subject: Re: LF: Happy Easter MF LF VLF
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Sender: owner-rsgb_lf_group@blacksheep.org
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org
Status: O

Hi Chris,

Here in DL we have cheap access to large PVC tubes, e.g. 
https://www.stabilo-sanitaer.de/kg-rohr-dn-250-1000-mm-kgem/a-438342/  
Just an example.
I think the situation is not much different in the UK.
PVC is not really the best material. Once arcing has occured on the 
surface there is a conducting track which will short cut any HV 
arrangement. Anyway, i have good experience with it and i'm using it 
some time now (right in this moment! :-) ) on VLF.
You need to keep the coil dry anyway and i really would recommend the 
use of Kapton tape directly on the PVC surface where the winding should 
be wound.
It is also recommended to do some basic calculations before starting to 
wind:

What is the capacity of the antenna? (Try to increase the C and height 
of the wire as much as possible. Worth to put some effort in there!)
What is the needed inductance then?
What is the maximum voltage the antenna will hold? (It sould be at least 
20 kV!)
Which antenna current can i expect at this voltage level?
Which wire diameter do i need so that my coil can permanently carry this 
current.?
Which coil length and diameter do i need to manage the voltage per turn? 
(Keep length/diameter < 2, use a diameter as high as possible/practicable)
(Which power do i need to produce that antenna current? (Depends on the 
coil and ground losses)).
Which wire length do i need?
What is the distance to Paul Nicholson? :-)

Oh yes, it would be nice to have a signal from the UK -> DL on VLF, it 
has always been the other way so far!

Keep us informed, show images and so on :-)

73, Stefan


Am 18.04.2017 13:58, schrieb Chris Wilson:
> Hello Stefan,
>
> Tuesday, April 18, 2017
>
>
> Thanks Stefan, I am toying with having a crack at VLF. I am wondering
> where I can find suitable 12 inch plus diameter tube to wind on,
> polycarbonate tube is ludicrously expensive in 3mm plus wall thickness
> and large diameters. My LF coil is wound around a round and near
> parallel sided nylon feed bin. I keep looking about, and although I
> have some 12 inch diameter field drain it's ribbed and unsuitable as
> is to wind upon. Anyone got any imaginative cheap sources short of
> nicking something from a construction site? ;)
>
>
>
>    
>> Am 16.04.2017 13:48, schrieb Chris Wilson:
>>      
>>> I  am  amazed  by pretty much everything Stefan does, I am hope he has
>>> some  financial  backing,  just  keeping him in copper wire and toroids
>>> looks  like  a  job  fro  a  wealthy man! Amazing stuff on VLF, simply
>>> amazing.
>>>        
>    
>> Many thanks Chris :-)
>> One day you will decide to join in :-) It's not a miracle to be down
>> there. The most relevant factor is not money but rather patience, e.g.
>> for winding a coil...
>>      
>    
>> Your LF signal is one of the best here in the moment! I can see you
>> daily in LF WSPR and OP32. Good job!
>>      
>    
>> 73, Stefan
>>      
>
>
>
>
>
>