Message-ID: <F06862D6B7B348E7849819EC005FA4C9@HughLaptop>
From: "Hugh M0WYE" <m0wye@radiouk.com>
To: <rsgb_lf_group@blacksheep.org>
References: <4DF11A78.4020401@iup.uni-heidelberg.de> <001901cc2743$81695dc0$0401a8c0@xphd97xgq27nyf> <4DF207EF.5060700@iup.uni-heidelberg.de> <003801cc276e$63c6f1d0$0401a8c0@xphd97xgq27nyf> <4DF24806.7030508@iup.uni-heidelberg.de> <004601cc2791$72c3d680$0401a8c0@xphd97xgq27nyf>
In-Reply-To: <004601cc2791$72c3d680$0401a8c0@xphd97xgq27nyf>
Date: Fri, 10 Jun 2011 19:58:30 +0100
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Subject: Re: LF: Re: First tests on VLF at DK7FC in Heidelberg
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PET - Polyester - is a recognised capacitor dielectric, and not particularl=
y=20
lossy.
I don't see why it shouldn't work - as long as you drink the cola first.
73
Hugh M0WYE


----- Original Message -----=20
From: "mal hamilton" <g3kevmal@talktalk.net>
To: <rsgb_lf_group@blacksheep.org>
Sent: Friday, June 10, 2011 6:11 PM
Subject: Re: LF: Re: First tests on VLF at DK7FC in Heidelberg


> Stefan
> Using LOSSY coca cola bottles as a dielectric is not recommended and poor
> stability makes things worse!!!!!!!!!
> With this information I do not think a QSO is possible
> de mal/g3kev
>
> ----- Original Message -----
> From: "Stefan Sch=E4fer" <Stefan.Schaefer@iup.uni-heidelberg.de>
> To: <rsgb_lf_group@blacksheep.org>
> Cc: "Paul" <paul@abelian.netcom.co.uk>; "Bernd Grupe"
> <bernd.grupe@t-online.de>
> Sent: Friday, June 10, 2011 5:36 PM
> Subject: Re: LF: Re: First tests on VLF at DK7FC in Heidelberg
>
>
> After a break i am back on air in this moment transmitting a long
> carrier. The signal generator is the DDS VFO, so stability is not
> perfect but should be suitable for 424 uHz i hope. It is a very first=20
> test.
>
> When using the antenna wire with maximum L i currently have available,
> the resonance is at 9.64 kHz, not to far away. I built a capacitor out
> of 2 aluminium plates and 2 coca cola bottles and come to resonance now
> on 8970 Hz. Before is used the bottles, i used stones. But they became
> HOT and later there was a black hole into them sparking around! These
> losses reduced the antenna power to less than 200 mA. Now i have about
> 500 mA antenna current and will transmit a longer dash until i see some
> traces on the grabbers, hopefully.
>
> When running the system without external addional C, so on 9.64 kHz, i
> am getting 360 mA antenna current at 80 W PA input power. The coil
> losses are 320 Ohm so the sourrounding losses seem to be about 300 Ohm
> which is not to much, thinking about trees and buildings...
>
> Now, i'll TX for some time, maybe 2 hours ort so.
>
> Any reports so far?
>
> 73, Stefan/DK7FC
>
>
> Am 10.06.2011 15:00, schrieb mal hamilton:
>> Stefan
>> My monitor is running/Speclab dfcw600 es Antenna 150 metre inv L up over
> 33
>> metres vertical. Condx all bands Good at present
>>
>> de mal/g3kev
>>
>> ----- Original Message -----
>> From: "Stefan Sch=E4fer"<Stefan.Schaefer@iup.uni-heidelberg.de>
>> To:<rsgb_lf_group@blacksheep.org>
>> Cc: "Paul"<paul@abelian.netcom.co.uk>; "Bernd Grupe"
>> <bernd.grupe@t-online.de>
>> Sent: Friday, June 10, 2011 1:02 PM
>> Subject: Re: LF: Re: First tests on VLF at DK7FC in Heidelberg
>>
>>
>> Hello Mal, VLF,
>>
>> OK, i am actually RX QRV on LF all the time here. And i have internet
>> during the test! :-)
>>
>> Now, the coil is on the roof and it's dry. I will prepare now... Maybe
>> the first VLF antenna current in a 20 minutes...
>>
>> 73, Stefan/DK7FC
>>
>>
>> Am 10.06.2011 09:53, schrieb mal hamilton:
>>
>>> Stefan
>>> I will leave my monitor on 8970 DFCW 600 mode. If I detect your signal =
I
>>> will reply on 137.7 CW or QRS3.
>>> 73 De Mal/G3KEV
>>>
>>> ----- Original Message -----
>>> From: "Stefan Sch=E4fer"<schaefer@iup.uni-heidelberg.de>
>>> To:<rsgb_lf_group@blacksheep.org>
>>> Cc: "Paul"<paul@abelian.netcom.co.uk>; "Bernd Grupe"
>>> <bernd.grupe@t-online.de>
>>> Sent: Thursday, June 09, 2011 8:09 PM
>>> Subject: VLF: First tests on VLF at DK7FC in Heidelberg
>>>
>>>
>>>
>>>
>>>> VLF,
>>>>
>>>> Tomorrow i plan to do first tests on 8970 Hz on my fixed antenna in
>>>> Heidelberg,
>>>> http://no.nonsense.ee/qthmap/?qth=3DJN49IK00WG&from=3Djn49ik00WD It is=20
>>>> about
>>>> 30m up.
>>>>
>>>> I'll start doing some resonating tests and may come on air in the
>>>> afternoon. The small PA (max. 300W) will be used in this first test
>>>> since it is easier to manage. Maybe the resonance will be some kHz
>>>> higher but i hope to come down into the Dreamers Band (TM).
>>>>
>>>> I expect to be visible on "local" grabbers like DF6NM, OE3GHB and
>>>> OK2BVG. If all works well i plan to transmit a longer dash, maybe 6000
>>>> seconds and later a short message in DFCW-600, like "K" or so, just fo=
r
>>>> the proof and to get a first impression about the efficiency of this
>>>> antenna.
>>>>
>>>> I had the idea to buy some flexible aluminium tube to form a toroid=20
>>>> that
>>>> will be placed on the top of the coil. Tis reduces the maximum E field
>>>> and adds some C, that might be needed to come down to 8970 Hz...
>>>>
>>>> Of course all this depends on the absence of rain but now i don't need
>>>> wind! Therefore, the signals will be about 20 dB lower, probably.
>>>>
>>>> The signal will be overload my grabber
>>>> http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber.html
>>>> that is in about 20 m (!) distance. Hopefully it gets not damaged due=20
>>>> to
>>>> several 10 kV on the wire.
>>>>
>>>> Is there someone who will watch for that signal?
>>>>
>>>> Reports would be very apprechiated!
>>>>
>>>> 73, CU, Stefan/DK7FC
>>>>
>>>>
>>>>
>>>
>>
>>
>
>
>=20