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
