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[linrad] Newbie's first impressions
For many months I have been meaning to get a Linrad system
running at K1JT. This weekend I had enough of the pieces
together so that I took the plunge. This note will share my
initial experiences. I hope it will encourage others to make the
effort to install and use this remarkable piece of software.
1. First, you must acquire a suitable computer. I decided to buy
a new (but cheap) PC and dedicate it to running Linrad. I bought
a "Dimension 4600" from the Dell factory outlet. This is the
home of so-called "refurbished" machines, but believe me, you
can't tell them from new. Mine is a 2.7 GHz Pentium IV with 256
MB RAM, a 40 GB, 7200 rpm disk, and on-board sound and video; I
use a monitor I already had on hand. Nothing fancy, but very
capable; total price was $409, including shipping.
2. Next, I installed Linux. I powered up the machine according
to the Dell instructions, and verified that under Win XP Home
Edition it behaved normally. I changed the BIOS Setup option so
that it can boot from a CD-ROM, inserted the Red Hat 9.0 Linux
Installation Disk 1, and told the machine to reboot. I don't like
"dual boot" machines much, so I wiped the Win XP and just
installed Linux using the Red Hat "workstation" default options
throughout. Installation completed normally in about half an
hour, and Linux was alive.
3. I downloaded and installed svgalib-1.4.3 and nasm, following
instructions on the Linrad Home Page. I changed the mouse
definition in /etc/vga/libvga.config from "Microsoft" to "IMPS2".
4. I downloaded and installed the free "demo" version of the OSS
5. I installed Linrad 01.17.
6. I connected an audio cable from my FT-847 to the computer's
"line in" sound connector.
7. I started Linrad and entered parameters shown in Leif's Linrad
article in QEX, installment #4, in which he discusses the use of
Linrad with an ordinary SSB receiver.
8. Going back to Linrad's main menu and pressing "A" to enter
weak-signal CW mode, I heard Linrad come alive! I tuned the
FT-847 to one of the weak beacons on 222 MHz, and started playing
with the Linux controls. What can I say? It just works! It
sounds good, the waterfall is terrific, the AFC works, you can
play with filter bandwidths to your heart's content, etc. The
"point and click" tuning is remarkable.
I was immediately and VERY FAVORABLY impressed!
Total elapsed time, from unpacking my new (ah, make that
"refurbished" Dell computer to listening to on-the-air signals
with Linrad, was about 15 hours. For 2 of those hours I was
doing yard work, and for 8 hours I was asleep: this was a
Saturday afternoon and Sunday morning project.
I have much to learn about Linrad. I have a Delta 44 sound card,
but have not yet installed it. I need to pay for the permanent
OSS license. My wide-bandwidth, quadrature mixing, dual
polarization front end presently exists only on paper. But
having had a taste of what Linrad can do, I am now eager to get
going with the rest of the project!
One goal (which does not even require the wideband receiver) is
to build a JT65 decoder onto the back end of Linrad.
I look forward to learning more of Linrad's capabilities from
those on this reflector with much more experience.
-- 73, Joe, K1JT