Hello all,
I have the same question. The 9khz_4mHz.usr can not be set to 6kHz just by
changing the frequency range or the center frequency. I am sure it's a simple
trick, but I could not find out. So I will have to use other settings - or
someone has a quick hint.
QRM/QRN is relatively low this morning. Possibly to high, but I will igve it a
try.
I am receiving with my T-Antenna and a my new hombrew preamp and soundcard.
Stefan, good luck - and to all the thousands of listeners, hi.
vy73 Horst DO1KHS/DI2AN
-----Ursprüngliche Nachricht-----
Von: mal hamilton <[email protected]>
Gesendet: 31.07.2010 17:35:20
An: [email protected]
Betreff: Re: VLF: DK7FC's 6th VLF kite experiment
>Stefan
>Who has a RX setup that will be able to look for your signal, I seem to be
>the only one so far. There is a trace on 8.97 at present but noone else can
>see it.
>There is very little response via this reflector and vy little acty at
>present on 137 and 500.
>de mal/g3kev
>
>
>
>
>----- Original Message -----
>From: "Stefan Schäfer"
>To: <[email protected]>
>Sent: Saturday, July 31, 2010 10:53 AM
>Subject: Re: VLF: DK7FC's 6th VLF kite experiment
>
>
>> Hello Peter,
>>
>> Better say 6,6 +-200 Hz. It is still not certain where the resonance
>> will be, sorry. There are to many assumtions, estimations and
>calculations.
>>
>> On 137 kHz the measured C for 100m is 580pF (measured with a RC bridge
>> and by measuring the L and calculating C). But EZNEC shows a lower C.
>> This could be, since a 100m vertical is not absolutely short against
>> Lambda and so the sems to occur some impedance transformation which
>> "looks/behaves" like a higherC.
>>
>> On <9 kHz the 100m wire IS short against lambda and so i loose this
>> benefit. There, the actual C is present. The L of my variometer part in
>> the BIG coil is estimated to be 30 mH. Maybe it is even more and the
>> overall L is higher than L(coil)+L(variometer) due to the better
>> magnetic coupling. So maybe i have less C and more L than thought on 8,97.
>>
>> When doubling the antenna height from 100m to 200m and assuming 5 pF/m
>> the C is doubled as well. So i thought i will come out at 6,34 kHz
>> (8,97/sqrt(2)). But this may just a rough estimate. EZNEC says the C
>> factor is not 2 but 1,88 so i would come out some 100 Hz above.
>>
>> So the question is:
>> What is the actual antenna C for 100m
>> What is the actual (maximum and average) L
>> What is the C factor when going from 100m to 200m
>>
>> This are many uncertainties and so i didn't want to tap the coil at 70%
>> of the winding to come back to 8,97 kHz but first just to measure out
>> where the resonance will be, to solve these open Questions. Of course,
>> another important and very interesting issue is propagation in the 46km
>> band! :-)
>>
>> So, sorry for that coarse frequency range. Maybe the actual QRG will be
>> written here in the reflector and can be seen on my garbber2 but first
>> lets hope for proper WX!
>>
>> 73 and tnx, Stefan/DK7FC
>>
>>
>>
>> Am 31.07.2010 11:23, schrieb pws:
>> > Hi Stefan,
>> >
>> > Question: do you have a realistic guess of the frequency window of your
>> > transmission around 6.5kHz, e.g. +-100Hz?
>> >
>> > You wrote:
>> >
>> >> ....
>> >> on *Sunday, the 1. August*, i will make a new kite experiment.
>> >> ...
>> >> i will transmit at arround *6,5 kHz,
>> >> ...
>> >> Starting time is* 8 UTC*, maybe some time later
>> >> ...
>> >> TX QTH is as usual in JN49IS, 49.77647N 8.699525.
>> >>
>> > Distance is 516km, heading 10deg. to Kiel.
>> >
>> > Just modified the software running at ~17mHz of resolution. Antennas are
>> > two crossed ferrite loops feeding some BC550 in parallel buffered by
>> > NE5532. Both amplifiers are connected to a M-Audio Audiophile 192
>running
>> > at 24 kHz on an Intel Atom 330 "shoe-box" under Linux.
>> >
>> > 73 from Baltic Sea,
>> > Peter
>> >
>>
>
>
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