It is interesting, thanks for information and nice picture.

Lubos, OK2BVG

BTW: It seems, my grabber works.

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> Date: Wed, 11 May 2011 16:42:46 +0200
> From: [email protected]
> To: [email protected]
> Subject: LF: Lf Frontend
>
> Hello group,
>
> Here a picture of my new LF frontend of my active antenna,
> http://dl.dropbox.com/u/19882028/LF/LF%20frontend.jpg
> It has a 2 stage bandpass filter in front of the first FET stage (BF862
> which is located on the back side). The Q is not very high but DLF and
> DCF49 are attenuated by about 15 dB. Additionally it provides a kind of
> HV protection, i hope ;-) But the main purpose is to filter VLF and MF
> and HF. On the older version i regularly saw MSK traces arround 136.6
> kHz. This is 153 kHz (DLF) minus 16.4 kHz (JXN)! :-)
> After some test time it moves in a water proof PVC tube now and is
> intended to run 24/7 on the grabber as the omnidirectional antenna.
> Further improvements will be done in the shack, perhaps.
>
> 73, Stefan/DK7FC
>