> --- On Mon, 22/2/10, Stefan_Schäfer
<
[email protected]> wrote:
>
>> From: Stefan_Schäfer <
[email protected]>
>> Subject: LF: VLF_8.79 kHz
>> To:
[email protected]>> Date: Monday, 22 February, 2010,
11:32
>>
>>
>>
>>
>>
>>
>>
>>
>> Ok Roger,
>>
>>
>>
>> And do you know if f<9kHz is free for other countries in
>> europe as
>> well? What about the UK?
>>
>>
>>
>> If such a grounded dipole is best, than it is easy to build
>> a big
>> antenna without the problems we have on LF (getting the
>> wire high above
>> ground). So we also could try big/long antennas. Waht do
>> you mean with
>> amateur levels? Power range is clear, something arround
>> 500W+-6dB. But
>> the antenna? Sure, if you think about building an antenna
>> in the
>> garden, say 2x20m, is not very effective but what about
>> 2x500m in a
>> forrest, perhaps with the loading coils (which will be on a
>>
ferrite
>> toroid i think) mounted 300m apart from the center? That
>> could be
>> interesting and easy to try. No tower, no earth radials,
>> just 2 wires
>> hung up on some trees and measured the impedance at the
>> feed point,
>> that would be a first step.
>>
>> This antenna will still be bad but what we are doing -on LF
>> it is the
>> same- is beeing fascinated to reach a good distance and
>> make some
>> contacts at very low frequencies, although it would be much
>> easier on
>> 40/80m...
>>
>> And so, if one would reach 50km with such a short dipole,
>> the
>> fascination would be enormous, isn't it? ;-)
>>
>>
>>
>> Has anyone, except Horst, tried such experiments as well?
>>
>>
>>
>> With the ground wave,
one could reach the whole europe, i
>> expect. But
>> that are dreams...
>>
>>
>>
>> Stefan/DK7FC
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> Am 22.02.2010 11:03, schrieb Roger Lapthorn:
>>
>> At this frequency, widely spaced, grounded
>> electrode pairs are
>> probably the best "antenna". There are
>> references to how these work in
>> the literature (for example NATO AGAARD papers from the
>> 1960s,
>> available on the internet I believe) and on one of the
>> German ham sites
>> (DK8KW) - see
http://www.qru.de/#vlf .
>>
>> Don't expect great ranges: up to 10kms is a fair
>> aim with modern
>> signal
processing technology and reasonable (amateur
>> levels) available
>> power. Project Sanguine achieved worldwide coverage to
>> submarines at
>> 76Hz (yes Hertz!) but used enormous power and antennas
>> stretching for
>> 100s of kms.
>>
>> 73s
>> Roger G3XBM
>>
>>
>>
>>
>>
>> 2010/2/22 Stefan Schäfer
>> <
[email protected]>
>>
>> Hello Horst,
>>
>>
>>
>> That sounds really nice. If it would be easy to find some
>> motivated OMs
>> in the near field (31km) ;-), that would be an interesting
>> field to
>> test.
>>
>>
>>
>>
Yesterday i have thought about possible antenna
>> configurations for that
>> range and got the idea that one could use a forrest as an
>> antenna
>> tower. There, you could hang up 100s meters of wire, in
>> series and in
>> parallel. You do not need to have that area beside your
>> house. Nobody
>> will see the wire and nobody will care about it.
>>
>> Since summer 2007 i have a horizontal loop antenna mounted
>> in some
>> trees on my hill with excellent results on all HF bands and
>> also 160m.
>> The loop has 130m and is mounted up to 12m above ground.
>> Perfect
>> matching from 160m to 10m with my symmetric tuner. I even
>> tried
>> matching on 2200m without a problem but with bad ODX
>> results, of
>> course. But if one would try 2x 10*100m on VLF, the ODX
>>
would be
>> interesting...
>>
>>
>>
>> JO30OT is abt 160km from JN49IS and thus a little far i
>> think ;-)
>>
>>
>>
>> What is your RX antenna and have you already catched some
>> commercial
>> VLF stations in that range? Are there some?
>>
>>
>>
>> 73, Stefan
>>
>>
>>
>> PS: One can be sure that there will never be SSB operation
>> ;-)
>>
>>
>>
>> ________________________________
>>
>>
>>
>> Von:
[email protected]
>> im Auftrag von Horst Stöcker
>>
>>
>> Gesendet: Mo 22.02.2010 09:29
>>
>>
An:
[email protected]>>
>>
>> Betreff: RE: LF: AW: Beaconing on 8.79 kHz in QRSS
>>
>>
>>
>>
>>
>>
>>
>>
>> Hallo Stefan,
>>
>>
>>
>> there was a notice in Funkamateur 12/05, S. 1287, that in
>> DL the range
>> <9kHz is free.
>>
>>
>>
>> I could not believe that so I asked the BNetzA and after a
>> while I got
>> a letter which confirmed that.
>>
>>
>>
>> So there nothing you've got to do for getting a
>> licence. You do not
>> need one.
>>
>>
>>
>> There is no limitation of technical parameters like
>> bandwith or
power.
>>
>>
>>
>> Hard to believe in german, but obviously true.
>>
>>
>>
>> My QTH is Siegburg JO30OT
>>
>>
>>
>> Horst
>>
>> ___________________________________________________________
>>
>> NEU: Mit
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>>
>>
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>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> --
>>
>>
>>
