On Wed, Mar 29, 2006 at 10:08:50PM -0600, Rick Parrish wrote:
> John Ackermann N8UR wrote:
>
> >the use of AFSK with 1200 and 2200Hz tones is simply an artifact of that.
>
> Instead of toggling back-and-forth between two independent tone sources,
> how hard would it be to create samples for a 12
John Ackermann N8UR wrote:
the use of AFSK with 1200 and 2200Hz tones is simply an artifact of that.
Instead of toggling back-and-forth between two independent tone sources,
how hard would it be to create samples for a 1200 hz tone spanning one
symbol period where the initial phase was arbit
On Wed, Mar 29, 2006 at 10:07:21PM +0200, Matteo Campanella wrote:
> yep, my fault to use the wrong name for it :-)
> I am indeed working on the bits to symbol (nrzi) block right now, and
> later on I am willing to do the HDLC block with flag, FCS and bit stuffing
> in order to put up the following
yep, my fault to use the wrong name for it :-)
I am indeed working on the bits to symbol (nrzi) block right now, and
later on I am willing to do the HDLC block with flag, FCS and bit stuffing
in order to put up the following chain:
message_source->hdlc->nrzi->modulation->duc
right now i am stuck
Having been an innocent bystander here, I think I see a classic case of
people talking past each other.
Matteo, the 1200 baud modulation used in AX.25 packet radio uses BEL 202
tones, *but* the signal that's being provided to the modulator has been
through an HDLC chip (or equivalent) that con
Hello!
I suspect, (And correct me if I am wrong here Bob!) that he was
getting some what annoyed by the questions. I strongly suggest that
you pursue this idea away from the list. And when you've got an
obvious question as to how it relates to the world of SDR then please
contact us. That's my opin
I'm quite surprised by this response of yours, as it is not exactly
aligned with the friendly style of the list - I know that to make things
clear is more difficult than slamming doors, but I like it more.
Maybe I am referring to the BELL 202 erroneously, because I am actually
trying to implement
Matteo:
Normally I do not play the game this way but let me suggest that you do
the following thing so we can get beyond this to give people the correct
information.
Open up Google. Type in BEL-202, hit enter. Please tell me WHOSE NAME
and DSP assembler code you see on the first several en
100011010 should become
10 0 0 11 01 0
space-space,mark-mark,space-space,mark-mark-mark-mark,space-space-mark,space
with the arbitrary decision on the first bit, that could be either space
or mark, as there is no previous state. space is 120
Bel 202 does NOT use Manchester encoding. The individual bits are NOT
sent bilevel but opposite polarity. Bel 202 very much as energy at DC
after demodulation which Manchester would eliminate. It does have
differential encoding but that is not Manchester.
100011010.
would be transmitt
On Wed, Mar 29, 2006 at 09:59:32AM +0200, Matteo Campanella wrote:
> bell 202 coding requires to send a steady tone (mark or space depending on
> the previous state) on 1 and a tone change on 0, so the tone change must
> happen in the middle of a bit.
>
> in order to use a modulator I guess I shou
bell 202 coding requires to send a steady tone (mark or space depending on
the previous state) on 1 and a tone change on 0, so the tone change must
happen in the middle of a bit.
in order to use a modulator I guess I should use a block to get a sequence
of symbols that is twice as long as the bit
I was just working on a similar project today. Attached is a file to
generate fsk using the fm modulator function. You should be able to
adapt it to your application.
Jeff#!/usr/bin/env python
#
# python code for gnuradio
#
# generate a binary continuous-phase fsk (cpfsk) signal using pseudo-
On Tue, Mar 28, 2006 at 11:51:03PM +0200, Matteo Campanella wrote:
> Hello, I am trying to find the best way to implement a bell 202 modem in
> gnuradio. The problem I am facing is that I need to produce two tones, one
> for mark and one for space, and I have to switch from one to other
> depending
Matteo Campanella wrote:
Hello, I am trying to find the best way to implement a bell 202 modem in
gnuradio. The problem I am facing is that I need to produce two tones, one
for mark and one for space, and I have to switch from one to other
depending on which symbol I am sending. The duration of t
Hello, I am trying to find the best way to implement a bell 202 modem in
gnuradio. The problem I am facing is that I need to produce two tones, one
for mark and one for space, and I have to switch from one to other
depending on which symbol I am sending. The duration of the tone (or tone
switch) mu
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