Frank wrote the keyer code that runs in PowerSDR and is distributed with
DttSP and wrote the ramp used in it as well as the agc. It is perfect
shaping. You could derive a Gaussian shape that would minimize the time
bandwidth product but the bandwidth would widen. It is better to spend
I am creating a new squelch block:
gr.pwr_squelch_cc
..that will replicate the current functionality of simple_squelch_cc,
and add an optional gating function. When gating is on, there will be
no output samples when the historical power is below threshold. With
gating off (the default), the
On Sat, Jun 17, 2006 at 12:58:12PM -0700, Johnathan Corgan wrote:
I am creating a new squelch block:
gr.pwr_squelch_cc
[...]
As far as naming goes, calling this pwr_squelch_xx is anticipation of
other squelch type blocks:
gr.pwr_squelch_ff - same as pwr_squelch_cc but for audio, like a
May I sound a cautionary note. Squelches that do not have a ramp are
not particularly kind to your listening sensibilities if this is to be
used to produce an audible signal. This means that the squelch will
ideally need a setting function for the ramp. The events are the same
as key
Norvald H. Ryeng wrote:
I've been thinking of using gnuradio and a USRP to record
all channels simultaneously, and that would require some of these
blocks.
In case you missed it, I posted a couple weeks ago a channelizer.py
program that does exactly this. You give it a frequency range and
Robert McGwier wrote:
May I sound a cautionary note. Squelches that do not have a ramp are
not particularly kind to your listening sensibilities if this is to be
used to produce an audible signal. This means that the squelch will
ideally need a setting function for the ramp. The events
Johnathan Corgan wrote:
Good catch. Would a linear ramp from 0.0 to 1.0 as a multiplier against
the audio stream, applied over a user specified number of samples, be
sufficient?
Yes, although half a cycle of a raised cosine is almost as easy,
and analytically correct.
73
Frank
AB2KT
Frank Brickle wrote:
Yes, although half a cycle of a raised cosine is almost as easy, and
analytically correct.
1/2 - cos(x)/2, for x from 0 to pi?
Should this be applied (in reverse) as a decay window when squelch cuts
in, as well as the attack window we've been talking about?
-Johnathan
