Message-ID: <50240D07.9030208@iup.uni-heidelberg.de>
Date: Thu, 09 Aug 2012 21:18:31 +0200
From: =?ISO-8859-1?Q?Stefan_Sch=E4fer?= <Stefan.Schaefer@iup.uni-heidelberg.de>
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Subject: Re: LF: Grabber
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Hello Giorgio,

This is very good news. I'm looking forward to your progress.

BTW many MF stations would be happy to have a CW sked on MF with IQ2MI, 
if possible :-)

For MF i have built a DC receiver but it is still not optimised because 
the band is still splitted. If i would optimise the filters then i would 
have no chance to receive stations on 502 kHz or on 501.3 kHz :-) So 
that, and the publication of the final schematic, has to wait a bit.

It depends on what is your goal: Simply having a receiver that does the 
job or the goal to have a completely homemade receiver. If you only want 
to receive then one of the new cheap SDR receivers will be an easy 
solution. A frontend has to be added though. Others may have better 
advice on that.

For 137 kHz i'm using this RX: 
https://dl.dropbox.com/u/19882028/LF/DK7FC%20LF-p%20RX%20converter.jpg
G4WGT is using a modification of that circuit on his grabber. And there 
is the kit of JA8SCD,http://icas.to/e/ The IDC-136 is used by TF3HZ and 
YV7MAE for example.

For VLF you already have a receiver, your soundcard! Here you only need 
to connect an antenna. I'm using this one 
http://www.iup.uni-heidelberg.de/schaefer_vlf/8,97kHz%20active%20E%20field%20antenna%20by%20DK7FC.jpg

73, Stefan/DK7FC


Am 09.08.2012 17:45, schrieb IZ2JGB:
> Hello group!
>
> After The esperiment with The 500khz
> IQ2MI beacon it's now time to build a suitable receiver / grabber.
>
> I'll like to start with The 480 / 500 khz,
> Then adding The 137 and maybe
> The vlf ( 0 - 20 )
>
> Any good / new ideas to start with ?
>
> Thanks
> IZ2JGB
> Giorgio
>