Patrick,
Thanks for the information. As you may have read from my
reply to Andy, my CPU usage seems to be very low with
Multipsk. It's well below 10%.
Is there a particular Multipsk mode or configuration that
would tax the system? I'd like to try it and see how it
affects CPU usage.
Merci mon ami...
Tony -K2MO
----- Original Message -----
From: Patrick Lindecker
To: digitalradio@yahoogroups.com
Sent: Friday, January 29, 2010 4:51 PM
Subject: Re: [digitalradio] SDR-Radio with DM780 20M
Digital Band
Hello Tony,
I have here two PC XP at about 2.4 GHz (single core):
I have compare these two XP computers on the same file to
decode (in 110A):
* the first one (the oldest) which is an AMD Atlon 2500+
1.09 GHz 768 Ko RAM takes 75 seconds to decode it,
* the second one which is an AMD Atlon 2400+ 2 GHz 736 Ko
RAM takes 20 seconds to decode it.
On the most modern (about 3 years old) with SdR and RS ID
detection on 44 KHz, the CPU load is about 35 to 40 %, but
on the old one it is 100 % (the program does not work in
fact).
So normally with a modern PC it is OK. With an "old" PC,
it can be problematic.
Note: with my Vista laptop (dual core), the CPU load is
about 25 % in the same conditions.
73
Patrick
----- Original Message -----
From: Tony
To: digitalradio@yahoogroups.com
Sent: Friday, January 29, 2010 8:36 PM
Subject: Re: [digitalradio] SDR-Radio with DM780 20M
Digital Band
Andy,
I plan on switching to SDR in the near future. My
current PC is a dual CPU 2.2GHz Dell with 3 GHz RAM. Any
idea what the minimum PC requirement is to run Multipsk with
SDR? Could you also tell us what processor you're running
now?
Thanks,
Tony -K2MO
----- Original Message -----
From: Andy obrien
To: digitalradio
Sent: Friday, January 29, 2010 9:11 AM
Subject: [digitalradio] SDR-Radio with DM780 20M
Digital Band
One of the things that I wanted to accomplish with an
SDR receiver,
is the ability to keep an eye on the whole 14065 to
14115 frequency
range. If I was down on 14074 monitoring ALE 400
traffic, I would
miss Olivia signals that popped up in the 14109 area.
I would also
miss Hell signals at 14068. Now the SDR affords the
opportunity to
keep an eye all all at once. My venture in to SDR from
a digital mode
perspective has led to a discovery that, other than
Multipsk, the
current state of the art does not support direct
monitoring of wider
I/Q data. I'm also challenged in that my PC cannot
cope with the
Multipsk CPU demand when I try direct monitoring. So,
at the moment I
am visually monitoring signals with the SDR and using
traditional
software methods to decode the 3-4 kHz of audio that
is fed from the
SDR to applications like DM780 or Fldigi.
At this screen shot
http://www.obriensweb.com/sdrdm780.jpg
you will see how it appears. I am simply using DM780
and SDR-Radio
software together. When I need to transmit, I just use
my TS2000
after dialing in the signal discovered by the SDR
receiver. Simon
HB9DRV will likely "integrate" these two applications
later in 2010.
I did catch a Russian on RTTY this morning that I
would have otherwise
missed while I was slumming it in PSK31-land.. Multisk
does RS-ID
over this entire 14065-14115 portion, and DM780 is
likely going to
include this ability in the future. If people use
RS-ID often enough,
it will be really "cool" to monitor 14065-14115 and
get RS ID alerts.
So, just over a week playing around with the SDR
receiver... I see the
potential... digital mode applications are not quite
"there" yet.
When they are "there" (as in Multipsk) my PC isn't.
This $41.00 Ebay
PC may eventually get retired for a slightly improved
one with better
CPU. OK, back to keeping an eye on 14065-14115. A-ha,
an SV3 calling
CQ RTTY, 14082.
Andy K3UK
