[PD] tuning an AM radio ideas

[Roman Haefeli]

hi nick again

i didn't want to 'steal' your idea, but i found this subject so
interesting, that i tried to realize that approach in a pd-patch.
the patch needs [abs~] from zexy and [lp8_butt~] from iemlib. the patch
has 3 'stations' (three sources modulated on differently tuned carriers)
and one 'receiver'. because of the very high sampling rate in the
subpatch (1.53MHz, when pd runs with 44100Hz), the patch eats quite a
lot of the cpu.
surprisingly it sounds a bit like am-radio, though the quality of the
received signal is very bad. the choice of the carrier frequencies does
have big effect on the typical am-radio artefacts.
there are sure some things, that could be improved. maybe you have use
for it.

cheers
roman


On Wed, 2006-12-13 at 12:45 +0000, nward04 at qub.ac.uk wrote:
> yep, Thats kinda the approach I was thinkin of. Off to read up on AM  
> radio a bit.
> thanks for the suggestions
> 
> On 13 Dec 2006, at 11:43, Roman Haefeli wrote:
> 
> > hi Nick
> >
> > a possibly stupid, unrealistic and very untested idea  comes to my  
> > mind:
> > why not build a real AM radio in pd? in a subpatch with a very high
> > samplingrate (using [block~]-object) you could amplitude modulate the
> > signal you want to transmit. with a narrow band-pass filter [bp~],  
> > that
> > is tuned to the carrier frequency, you could get back the amplitude of
> > the original signal. maybe you add some [noise~] to simulate cosmic
> > radiowaves.
> > just a few ideas. i would be interested, if this approach has a chance
> > to work....
> >
> > roman
> >
> > On Wed, 2006-12-13 at 11:04 +0000, nward04 at qub.ac.uk wrote:
> >> Hi all,
> >> I was just wondering would anyone here have an idea on a starting
> >> point for a patch to simulate tuning in a station on an AM radio. I
> >> want to make a virtual radio with say 5 chanels that i can tune
> >> between replete with the hissing fizzing in between out of tune bits.
> >> Thanks
> >> Nick

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