Message-ID: <012501c35235$95148480$fae486d4@bryan2>
From: "captbrian" <captbrian@ukonline.co.uk>
To: rsgb_lf_group@blacksheep.org
Date: Thu, 24 Jul 2003 23:44:36 +0100
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Subject: LF: Re: Re: Re: LF station in Bavarian Mountains
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Imagine "laengstwellenfunk" in QRSS!
Bryan
-----Original Message-----
From: Matti Niemela <mattis.niemela@kolumbus.fi>
To: rsgb_lf_group@blacksheep.org <rsgb_lf_group@blacksheep.org>
Date: 24 July 2003 21:17
Subject: LF: Re: Re: LF station in Bavarian Mountains


>Hello LF-Group,
>
>In a book Klawitter-Herold-Oexner: "Langwellen- und Laengstwellenfunk" by
>Siebel Verlag (2000) is a good description of Goliath system pp 47-52 and
>also info about other historical VLF-LF stations.
>
>73 Matti/OH2ZT
>
>----- Original Message -----
>From: "Hans-Joachim Brandt" <hajo.brandt.dj1zb@t-online.de>
>To: <rsgb_lf_group@blacksheep.org>
>Sent: Thursday, July 24, 2003 10:05 PM
>Subject: LF: Re: LF station in Bavarian Mountains
>
>
>Dear Group,
>
>as far as I know, living in eastern Bavaria, just a few concrete blocks can
>be found on the mountains mentioned, which have carried the antenna wires.
>
>For more details I guss I had to contact Karl Hille, DL1VU, who lives
closer
>to that region (he is a true bavarian, older than me, and lives there since
>a long time).
>
>But concerning the Lorenz Company, they got their chance to build a VLF
>station at the beginning of the second world war for erecting the so-called
>"Goliath" station for communication with submarines, operating at
>16 kHz with 1 MW transmitter output and 50% antenna efficiency, employing
>the Alexanderson principle. In the "German Museum" in Munich I have read in
>a book that submarines before New York could copy this station at a depth
of
>16-20 meters, and at about 8 meters before Japan, using magnetic aerials.
>
>This station has never been bombed by the allied forces (obviously they
>wanted to observe the traffic). The book said that at the end of the war
the
>exciter stages were destroyed by the Germans, later the Russians rushed in,
>dismantled the station and put the transmitter into acitivity again in the
>Soviet Union employing russian tubes. Nothing could be said in this book
>about the condition of the ground system.
>
>HW?
>
>73 Ha-Jo, DJ1ZB
>
>
>"captbrian" <captbrian@ukonline.co.uk> schrieb:
>> Quick ! , - Is it still there ?   ;-))
>>
>> Bryan - G3GVB
>> -----Original Message-----
>> From: Dick Rollema <d.w.rollema@freeler.nl>
>> To: LF-Group <rsgb_lf_group@blacksheep.org>
>> Date: 24 July 2003 14:54
>> Subject: LF: FS formula
>>
>>
>> To All from PA0SE
>>
>> William Oorschot, PA0WFO, has sent me a copy of a three part article by
>> Karl H. Hille, DL1VU, in the German 2002 magazine FUNK: "Die Bergantenne
>am
>> Herzogstand - Vor 75 Jahren eine technische Grosstat" (The mountain
>antenna
>> at the Herzogstand - For 75 years a technical amazing feat).  This
>concerns
>> the following.
>>
>> The large VLF stations at Nauen and Eilvese in Germany that were on the
>air
>> around 1920 were built by Telefunken. The German firm Carl Lorenz AG
would
>> like to supply VLF stations as well but were unable to do so. They could
>> supply arc-transmitters of sufficient power but not the enormous antenna
>> masts they had to offer with the transmitters in order to compete with
>> Telefunken. Steel masts were unacceptably expensive around 1920 due to
the
>> unbelievable strong inflation that started at the same time Lorenz began
>> planning the station. So they looked for an alternative. There was an
>> example. For the VLF link between the Netherlands and the Netherlands
East
>> Indies (now Indonesia) a large arc-transmitter hand been constructed at
>> Malabar on the island Java. The antenna hung over a valley between two
>> mountains, obviating the use of high masts.
>> Lorenz decided to do the same. They strung an antenna between two
mountain
>> tops in the South of Germany, the mountains were the Herzogstand at 1735m
>> and the Stein at 940m. The horizontal distance between the mountain tops
>> was 2700m.  About one third from the low end of the sloping wire an
>> insulator was inserted and a vertical wire connected the part to the
>> Herzogstand to the transmitter in the valley. So an L-antenna resulted,
>fed
>> against an extensive earth system, using multiple electrodes in marsh
land
>> around the station.. The efficiency of this configuration was found to be
>> higher than for a T-antenna, in which the whole sloping wire between the
>> mountain tops was used.
>> Using a 500W valve transmitter strength measurements were performed over
>> the whole of Germany and the efficiency of the antenna system was found
to
>> be comparable to the one of Nauen, that consisted of two 250m masts,
seven
>> 210m masts, two 180m masts and four200m masts.
>> In 1926 the station was ready but it did not become operational as by
that
>> time it  had been found that on short waves a few kilowatt and a small
>> antenna could provide long distance communication equal to or even better
>> than on VLF.
>> The reason I mention all this that the article contains an interesting
>> formula for field strength at the surface of the earth around  a vertical
>> antenna. The formula comes from a 1926 publication by  M. Bäumler.
>> (also as attachment).
>> Field Strength.jpg
>> E = field strength in V/m
>> I = current in the current maximum of the antenna.
>> hw = effective height in m.
>> lambda = wave length in m.
>> d = distance in m.
>> j = operator for 90 degrees phase shift.
>>
>> The first part gives the far field; the second part the electric
component
>> of the near field. The far field diminishes with 1/d, the near field with
>> 1/d squared. At 2 wavelength distance the near field is 8% of the far
>> field, at 4 wavelength 4% and at 16 wavelength 1% of the far field.
>> It is clear that the formula is only correct over perfect earth. But at
>the
>> distances where field strength measurements are usually performed, and
>> certainly at VLF, the influence of the real earth on the field strength
is
>> negligible.
>> The term effective height is now mostly used in connection with antennas
>> for reception.
>>
>> Now an example:
>> A vertical antenna of 20m at 136kHz has an effective height of 10m and a
>> radiation resistance of 0.028 ohm.
>> To radiate 1kW the current must be 189A. The wavelength is 2205m.
Entering
>> these figures into the formula we find the far field at 1km distance to
be
>> 0.323V/m, which compares well with the 300mV/m that is given by the CCIR
>> curves for ground wave propagation.
>>
>> 73, Dick, PA0SE
>> JN22GD
>>
>>
>>
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