[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[linrad] Re: MAP65
- Subject: [linrad] Re: MAP65
- From: Joe Taylor <Princeton.EDU; joe@xxxxxxxxxxxxxxxx>
- Date: Wed, 08 Aug 2007 10:27:24 -0400
When I receive an email from "root", I always know that it
comes from a Linrad user!
I hope you do not mind if I copy this reply to the Linrad
reflector. I think your question and my answer may be
interesting to others.
Hello Joe, a simple question.
I use Linrad by long and long time, but
with only "H" pol antenna. My question is
may i use MAP65?
And if the answer is positive, may i use it with results,
on my Notebook with the AC97 soundblaster and without wire (cross cable)
connection, right as i do today, where i have the main PC with Ubuntu
and Linrad and the notebook with the wsjt. They are only connected via
As I understand it, you are connecting Linrad's audio output
to audio input on the Notebook, using an audio cable. WSJT
runs on the Notebook, and gives you a bandwidth of something
like 2-4 kHz, right?
This procedure will not work for MAP65, because MAP65 wants
to have access to the full 90 kHz bandwidth available inside
Linrad. (I am assuming that your Linrad setup uses 96 kHz
sampling, as I do.)
For your setup to work with MAP65 you can use one of these
1. Run both Linrad and MAP65 on the Linux computer. This
may be an attractive possibility if this computer is fast
(say, 2.4 GHz or faster CPU) and has plenty of memory (at
least 1 GB). You will need two display screens -- and
therefore either two video cards, a dual-monitor video card,
or "remote display" of the MAP65 information to a second
computer connected by ethernet. You might also need as many
as three sound cards: for example, a Delta44 for Linrad
input, the motherboard AC97 for Linrad sound output
(required only for human monitoring), and a cheap add-on
card for sending the Tx audio from MAP65 to your transmitter.
2. Run Linrad in your Ubuntu Linux machine and MAP65 in the
Windows Notebook. This is probably simpler, and is
certainly closer to what you have now. The Linrad setup
stays as it is, but you enable its multicasting "network
output" of 16-bit timf2 data . The two computers must be
connected to the same local area network, either through an
ethernet switch or on a private RJ45-style crossover cable.
MAP65 receives its data input from the ethernet port, and
sends Tx Audio to the transmitter. You will want to have at
least 1024 x 768 screen resolution on the Notebook.
ciao and thank you in advance
One additional point. I solved the problem I was having, in
which the Linrad --> MAP65 multicast data stream swamped my
in-house LAN so that my wife could not read email on her
computer. I changed the code in Linrad so that instead of
using "multicasting," it sends the UDP packets explicitly
("unicast") to the IP address of my MAP65 computer. Then
they do not pass through the cheap ethernet switch to which
the computers are connected, and Marietta is happy again
because her part of the network is not swamped.
I will be happy to help more, if I can -- but you should
know that I will be away on vacation (at the beach, with
grandchildren) for the next three weeks.
-- 73, Joe, K1JT
This message is sent to you because you are subscribed to
the mailing list <linrad@xxxxxxxxxxxxxxxxxxxxx>.
To unsubscribe, E-mail to: <linrad-off@xxxxxxxxxxxxxxxxxxxxx>
To switch to the DIGEST mode, E-mail to <linrad-digest@xxxxxxxxxxxxxxxxxxxxx>
To switch to the INDEX mode, E-mail to <linrad-index@xxxxxxxxxxxxxxxxxxxxx>
Send administrative queries to <linrad-request@xxxxxxxxxxxxxxxxxxxxx>