LF: Re: Re: Re: Optimal width for LF?

["f5maf" <f5maf@free.fr>]

Thanks Petr for these answers.
I am very interested to make a new receiver:!
73 marc F5MAFf
-----Message d'origine-----
De : Petr Maly <p.maly@gmc.net>
R : rsgb_lf_group@blacksheep.org <rsgb_lf_group@blacksheep.org>
Date : lundi 15 mai 2000 18:22
Objet : LF: Re: Re: Optimal width for LF?


> I mix 10 MHz VXO with 8863 kHz  XO. Stability looks sufficient, all this
> gear will be placed in closed robust alluminium box which will be
surrounded
> by polystyrene casing to provide temperature isolation. I wanted to have no
> tuning step to be able to use extremely narrow filters.
>
> 73, Petr, OK1FIG
>
>
> ----- Original Message -----
> From: mv tsi <mv.tsi@laposte.net>
> To: <rsgb_lf_group@blacksheep.org>
> Sent: Monday, May 15, 2000 1:32 PM
> Subject: LF: Re: Optimal width for LF?
>
>
> > Hello petr,
> > I am interested to make a receiver.
> > But what technology can you use for hight stability frequency?
> > VFO,DDS?
> > My first receiver used a 3Mhz VFO and a IF at 11Mhz.
> > (I had a 137Khz 14 Mhz converter).
> > I had some probleme to have a narrow band pass with 5 cristals (800Hz).
> > For reduct audio band pass I used a MF10.
> > But with this receiver I couldn't survey a frequency during more hours.
> > The VFO stability had  no perfect.
> > 73 marc.
> > ----- Original Message -----
> > From: Petr Maly <p.maly@gmc.net>
> > To: 136 group <rsgb_lf_group@blacksheep.org>
> > Sent: Friday, May 12, 2000 2:34 PM
> > Subject: LF: Optimal width for LF?
> >
> >
> > > Hello all
> > > I am just designing a new RX for 136 kHz band. It will have IF on 1 MHz
> > with
> > > high quality x-tal filter with bandwidth 200 Hz. The main selectivity
> will
> > > by obtained on AF with passive filter with coils on pot cores. Till now
> I
> > > used similar filter with bandwidth about 50 Hz and it seems to be still
> > too
> > > wide for LF. I was about to make it new with 15 Hz width. Somebody here
> > > mentioned 1 Hz wide filter which seems to me to be too narrow. At
least,
> > the
> > > filter cannot be narrower than obtainable osc stability. Can we make a
> > > little questionnaire here? What bandwidth do you use and what is the
> > > experience?
> > >
> > > 73, Petr, OK1FIG
> > >
> > >
> > >
> > >
> > >
> > >
> > >