Re: LF: Re: RE: MF tonite

[Stefan Schäfer <Stefan.Schaefer@iup.uni-heidelberg.de>]

Hi Ken,

OK but later. I want to try some modifications, i.e. using the 500 Ohm 
input and the 18 kOhm output, to have some gain. If this does not affect 
the matching, i would prefer that...
73, Stefan
Am 13.09.2012 20:43, schrieb Ken:
> Stefan.
> Thank you for the info, maybe sometime you will be able to post the circuit?
>
> 73.
>
> Ken
>
> M0KHW
>
> -----Original Message-----
> From: owner-rsgb_lf_group@blacksheep.org
> [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Stefan Schäfer
> Sent: 13 September 2012 12:26
> To: rsgb_lf_group@blacksheep.org
> Subject: Re: LF: Re: RE: MF tonite
>
> Ah yes, Thomas was faster, damn ;-)
>
> Another image from the experimental setup, using source followers
> https://dl.dropbox.com/u/19882028/MF/Mechanical_filter_with_source-followers
> .JPG
> The results have been very good last night!
>
> 73, Stefan/DK7FC
>
>
> Am 13.09.2012 13:12, schrieb Thomas Rosenkranz:
>    
> > Hy Ken,
> >
> > the name of the mechanical filter is FZ02
> > http://www.oppermann-electronic.de/html/hf-spezialbauteile.html
> >
> > http://dm4tr.bplaced.net/index.php?section=Receiver
> >
> > 73
> > Thomas DM4TR
> >
> >
> > ----- Original Message ----- From: "Ken"<ken.h.wright@btinternet.com>
> > To:<rsgb_lf_group@blacksheep.org>
> > Sent: Thursday, September 13, 2012 10:28 AM
> > Subject: LF: RE: MF tonite
> >
> >
> > Hi Stefan.
> > What mechanical filter are you using?.
> > 73.
> > Ken
> > M0KHW
> >
> > -----Original Message-----
> > From: owner-rsgb_lf_group@blacksheep.org
> > [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Stefan Schäfer
> > Sent: 12 September 2012 21:02
> > To: rsgb_lf_group@blacksheep.org
> > Subject: LF: MF tonite
> >
> > Christian,
> >
> > Are you QRV tonite? I would like to see or better hear the difference of
> > my RX performance when using my band filter i was testing in the
> > afternoon.
> >
> > It is the mechanical filter which uses source followers at the input and
> > output, to provide a constant accurate impedance matching to keep the
> > passband ripple as low as possible. The afternoons tests have been very
> > promising, see https://dl.dropbox.com/u/19882028/MF/MF%20Filter.png
> > This is the frequency response:
> > https://dl.dropbox.com/u/19882028/MF/473%20kHz%20ZF%20Filter%2040%20dB.png
> >      
>    
> > There should be a much better image rejection now and so maybe a few
> > more dB SNR... Unfortunately the filter does not cover the 502 kHz
> > region. But this problem will be gone in some months...
> >
> > Will be on 472.5 kHz soon.
> >
> > 73, Stefan/DK7FC