FPGA Central

It is really possible to use FPGA to generate FM Radio signal DIRECTLY
in most cases there radio will pickup signal from PCB trace already

i did only a very little experiments (wrote in june issue also a
little)

even using audio signal to invert phase will produce signal that is
received
as FM modulation (with low modulation index) using simple NCO gives
much better results.

Antti

Why would you think it would not be possible or even hard? FM is a
very simple modulation scheme and using an NCO should produce very
acceptable results.

Rick


On Jul 1, 11:11*am, Antti <Antti.Luk...@googlemail.com> wrote:
> It is really possible to use FPGA to generate FM Radio signal DIRECTLY
> in most cases there radio will pickup signal from PCB trace already
>
> i did only a very little experiments (wrote in june issue also a
> little)
>
> even using audio signal to invert phase will produce signal that is
> received
> as FM modulation (with low modulation index) using simple NCO gives
> much better results.
>
> Antti

On Jul 1, 7:09*pm, rickman <gnu...@gmail.com> wrote:
> Why would you think it would not be possible or even hard? *FM is a
> very simple modulation scheme and using an NCO should produce very
> acceptable results.
>
> Rick
>
> On Jul 1, 11:11*am, Antti <Antti.Luk...@googlemail.com> wrote:
>
> > It is really possible to use FPGA to generate FM Radio signal DIRECTLY
> > in most cases there radio will pickup signal from PCB trace already
>
> > i did only a very little experiments (wrote in june issue also a
> > little)
>
> > even using audio signal to invert phase will produce signal that is
> > received
> > as FM modulation (with low modulation index) using simple NCO gives
> > much better results.
>
> > Antti

yes, after thinking a little yes

funny eveb PHASE inversion produces audible results,
with nco should be possible get yes, maybe quite acceptable
results, i did just a few tests, and i only had 1 bit audio to use
as modulation, and the result was pretty good actually,
much better than small piezo buzzer would do...

maybe I assumed that real modulation is required
but using nco clocked at 2x the output and modulating around
mid frequency, hm maybe even that isnt required the
receiver should overage it all and receive anyway

Antti

Antti.Lukats@googlemail.com wrote:
> maybe I assumed that real modulation is required
> but using nco clocked at 2x the output and modulating around
> mid frequency, hm maybe even that isnt required the
> receiver should overage it all and receive anyway
of course, you won't make a commercial product out of this hack, right ?
your system certainly makes so many out-of-band noise that
it won't pass any certification... radio is black magic for me...

But computers and radios have had a long story of love & hate.
On some old IBM tube-based mainframes, there was a radio reciever
that picked up the internal noise, which the operators were used to.
When the machine hung, the operator would instantly "hear" it...

Also, I've read that the Altaïr computer kit (was it this one ?) was
once used to run a specific program that disturbed a close radio
so music would be heard...

Have fun anyway,

> Antti
yg
--
http://ygdes.com / http://yasep.org

whygee <whygee@yg.yg> wrote:

< But computers and radios have had a long story of love & hate.
< On some old IBM tube-based mainframes, there was a radio reciever
< that picked up the internal noise, which the operators were used to.
< When the machine hung, the operator would instantly "hear" it...

I use to hear stories about computers with speakers actually
connected to some internal signal. The same idea, when the
sound was repetitive the program was in a loop, and the
operator would kill it.

My father had problems with programs that were supposed to
have long loops getting killed too early.

-- glen

On Jul 2, 3:11*am, Antti <Antti.Luk...@googlemail.com> wrote:
> It is really possible to use FPGA to generate FM Radio signal DIRECTLY
> in most cases there radio will pickup signal from PCB trace already
>
> i did only a very little experiments (wrote in june issue also a
> little)
>
> even using audio signal to invert phase will produce signal that is
> received
> as FM modulation (with low modulation index) using simple NCO gives
> much better results.

Interesting, but it will have a fat spectrum...?
You could get (somewhere) into the FM band easily enough with a ring
oscillator,
and the average frequency could tell you the die temperature
Modulate one gate in that chain,and you get FM,
Modulate Vcc, and you also get FM ...

Next thing to do, is look at the Traffic Data information some radios
can
receive, and send real messages to your FM radio...
You could give the spooks a real fright with that one..

-jg

In article <4a4bd06d$0$291$7a628cd7@news.club-internet.fr>,
whygee <whygee@yg.yg> writes:
|>
|> Also, I've read that the Alta=EFr computer kit (was it this one ?) was
|> once used to run a specific program that disturbed a close radio
|> so music would be heard...

No idea about the Altair, but I had a similar program on my ZX81/TS1000.

Rainer