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Hello Gerhard, Ossi,
"The only problem is wind. Even when you can't feel the wind on the ground, as soon as you reach 50m, the balloons will drift away caused by wind, thus lowering the height. Ossi lives in a region where days with absolutely no wind
are rare. Yesterday wind was weak and so he reached nearly 80m at nearly 90 degrees"
maybe a "helikite" can help ?
http://www.allsopp.co.uk/
http://www.qsl.net/g4vgo/antenna1.htm
73, Rik ON7YD - OR7T
________________________________________
Van: [email protected] [[email protected]] namens Gerhard Hickl [[email protected]]
Verzonden: zondag 28 november 2010 8:55
Aan: [email protected]
Onderwerp: Re: VLF: Carrier on 8969.955 Hz
Hello group!
Ossi asked me to give you an overview about his set-up.
We spent many ours on the phone during the past weeks and I assisted him
in building the system.
The PA is a car-audio equipment running at 25A / 14V followed by a
toroid-transformer about 5T/50T. Transmission line is abt. 30m of
existing RG58 (also used for LF). The inner wire connects directly to
the cold-end of the loading coil and the shield is connected to the
existing grounding-system (a lot of buried wires), which was enforced by
many (>100) square-meters of wire-fence and wire-grid (usually used for
plastering walls) laying on the lawn. This reduced ground-loss
significantly.
The coil is made of different kinds of wires. The main-coil is made out
of 0,6mm enamel wire wound on a plastic water-barrel (abt. 400liters)
and there are 2 or 3 smaller coils made of installation-wire which are
coupled to the main-coil by varying the distance. In total, the coil has
about 300-400mH, depending on actual set-up.
Ossi is using one of the top-load wires of the existing LF antenna (20m
vertical) to have it lifted by the balloons. The balloons are made out
of latex (9€) having a volume of abt. 1m³ when totally inflated. If so,
one balloon will lift 900 grams of weight. One Helium-bottle is abt. 4m³
and the price is abt. 120€. Ossi found out that it is better not to use
one balloon totally inflated but rather two of them only inflated to
half of the volume. This is reducing gas-loss trough the shell
significantly because the material is not stretched so much. He filled
the first balloon a week ago and didn't notice any degradation until
now. So my guess is that they will be usable for at least 2 weeks.
The only problem is wind. Even when you can't feel the wind on the
ground, as soon as you reach 50m, the balloons will drift away caused by
wind, thus lowering the height. Ossi lives in a region where days with
absolutely no wind are rare. Yesterday wind was weak and so he reached
nearly 80m at nearly 90 degrees.
Ossi measured the antenna current but only with some "multimeters" and
I'm not sure how accurate they are. From the reading of the those
meters, the antenna current is 1.6A at full power which is rather high.
Knowing Ossi, I'm sure he will improve the setup during the next weeks
and so you can expect more and stronger signals from OE.
73
OE3GHB
Gerhard
Am Sonntag, den 28.11.2010, 00:57 +0100 schrieb Stefan Schäfer:
> Ossi, Markus, VLF,
>
> Congratulations to Ossi! This is a distance of 377 km to my grabber. The
> signal was well visible in the 6000' window and a faint trace was
> visible in the 600' window. Furthermore it is the first signal on my
> grabber that comes not from Markus or me :-) The first
> Austria(TX)-Germany(RX) contact on VLF!
>
> Tell us more about the setup and the ballon! How expensive is one helium
> filling? Or have you generated your own hydrogen? :-) What was the
> antenna current? When will be the next transmission?
>
> 73, Stefan/DK7FC
>
>
>
> Am 27.11.2010 15:46, schrieb Markus Vester:
> > Excellent, Ossi, congratulations! Welcome to the club ;-)
> >
> > 73, Markus
> >
> > From: [email protected]
> > Sent: Saturday, November 27, 2010 3:39 PM
> > To: Markus Vester
> > Subject: Re: VLF: Carrier on 8969.955 Hz
> >
> > Markus Vester wrote:
> >
> >> Today between 9:55 and 11:50, a carrier appeared near 8969.955 Hz, with
> >> a slight downward drift. It is visible both in Heidelberg
> >> http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber.html
> >> and in Nürnberg
> >> http://www.mydarc.de/df6nm/vlf/vlfgrabber.htm ,
> >> here about 10 dB SNR in 0.95 mHz FFT.
> >>
> >> So the signal is getting out well...
> >>
> >> Best 73,
> >> Markus (DF6NM)
> >>
> >>
> > hallo markus !
> > habe heute eine testaussendung gemacht mit meiner lwantenne ,
> > habe eine dachkapazität mit ballon ca 90 meter aufsteigen lassen
> > spule mit ca 280 mh und caramp mit 200 watt out ,
> > habe die erdverhaeltnise mit ca 150 m drahtgeflecht im garten verlegt. .
> >
> > fuers erste mal ist es ja ganz gut gegangen zu dir und stefan ,
> > leider ist mein vfo nicht so stabil.
> > beste vlf gruesse 73 ossi oe5odl
> >
> >
> >
>
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