Message-ID: <57101A93.9050904@posteo.de>
Date: Fri, 15 Apr 2016 00:32:51 +0200
From: DK7FC <selberdenken@posteo.de>
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To: rsgb_lf_group@blacksheep.org
References: <8D363D5D172D923-15A0-65ABC1@webmail-vd012.sysops.aol.com> <570EAFD1.8@posteo.de> <570EBA18.7050409@abelian.org> <57100539.4090905@posteo.de>
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Subject: Re: LF: TXing on VLF again, A fan in series to the antenna?! :-)
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VLF,

BTW the calculated ERP is 150 uW. Quite low :-( But i will be able to 
run it permanently...

The transmission is now stopped and was running from 20:45...22:30 UTC.

73, Stefan

Am 14.04.2016 23:01, schrieb DK7FC:
> Hi VLF,
>
> Since 22:45 i'm running 200 mA on 8270.0050 Hz into my antenna again. 
> 200 mA is the limitation of this compact yoghurt-coil. The overall 
> system loss is about 1 kOhm, so i just need 40W to run the system at 
> 100%. Or, in other words, power is not the limiting factor :-) There 
> are holes into the single yoghurt cups so there can be an air flow in 
> the cups. And this will be helpful/necessary in summer / daytime.
> 200 mA is about the current consumption of a 12V fan used in PC power 
> supplies. So i've constructed a plate with a fan mounted on that, 
> improvong the air flow. Later, a tube must be used to form a curve on 
> the top of the arrangement to prevent water from flowing between the 
> coils. Then, a forced air flow becomes necessary, normal thermal 
> convection could be to small.
> https://dl.dropboxusercontent.com/u/19882028/VLF/20160414_214939.jpg
> https://dl.dropboxusercontent.com/u/19882028/VLF/20160414_215835.jpg
> A normal bridge rectifier with UF4007 diodes, then 2 ZD15 Z-diodes, a 
> single UF4007 diode (to reduce the voltage a bit) and a 100nF C, 
> that's all. It works very well and automatically :-)
>
> 73, Stefan
>
>
>
> Am 13.04.2016 23:28, schrieb Paul Nicholson:
>>
>> Sorry Stefan, nothing showing for 20:14,+30m in
>> 555uHz.   The noise floor there is 0.2 fT probably
>> due to all the thunderstorms in Europe tonight.
>> I expect your signal is down below 0.1 fT.
>>
>> Also checked 20:14,+60m in 278 uHz in case you ran
>> for a full hour, but nothing.
>>
>> Let's try again when the background is lower.
>>
>> -- 
>> Paul Nicholson
>> -- 
>>
>