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Re: Linrad for newcomers

Hi Leif,

thanks for the feedback and first level aid!
I am in close contact with Pierre for the TS850-driver, he's developing for YO4AUL and the first version 
worked here ufb. This was tested before the holidays.
I know now he's very qualified with sound and C and (Linux) programming...

"Apt-getting" is also possible with Ubuntu and works fine...
Thanks for the overview list...

Cgrts with the "latency" improvements.
I've to follow this closely since I've a "small boys dream" to have a working radar... 
On 2m it is very challenging and today far over my capabilities!

BTW:
An old friend of my QRO (now SK) is very qualified in this matter but has no time... He's still working in the telecom sector (Kenwood-dealer) and supporting the french part of the belgian TV for helicopter and other comm's.
In the 70's, he was working closely with ON4FG (SK for some time), Gaby Felix, and while having built the EME-antenna and testing it on their high power PA, the antenna "burnt"...the whole street was smelling.. ;-) Always nice stories to hear... 

I am sure you contacted ON4FG. He was a true VHF-pioneer.
He's been making movies as a camera-man for the belgian TV and bought a nice place in the Antwerp province (highest spot at 40m or so asl) where nowadays still a lot of VHF-contests are held...
My old friend made several military developments and he told me he's made several high power PA's for about 23cm (10kW? with Eimac klystrons) to ionize clouds to cover 1200km and more ... He was not allowed to say more because it is military so I miss vital details... I can only believe him since he's the lathe and A LOT of measurement equipment to make the cavities, etc...
For the Tx side, I have the Elecraft K2 (but still without interface to Linrad) which is capable of QSK. I understand, you intend to bring Linrad also where it could be used as radar... I heard that G4FUF uses this method to detect Es openings but I am not sure it is on 2m. 


73 for now and thanks...

Michel, ON7EH
----- Original Message ----- From: "Leif Asbrink" <leif@xxxxxxxxxx> 
To: "on7eh" <on7eh@xxxxxxxxx>
Sent: Thursday, July 17, 2008 1:28 AM
Subject: Re: Linrad for newcomers



Hi Michel,


Mode parameters.First time.
after the last of the three screens, an output sampling speed is selected of 48kHz but it is written: with 48kHz for the loudspeakers, the Nyquist frequency is 24kHz. Shouldn't this be the opposite? 
Hmmm, it was not well written. I have made a couple of
changes:-)


7 lines above "setup procedures  for the radio hw":
br> and "mouse controls"

OK:-)
---------------------------------------------------------------------------------------------------------------------------------------------------
I've just started Linrad 02.47 and 02.43 and OSS 4Front is still running... 
So I guess it will be early August my free usage OSS will end...

I'll wait for your 02.49 to have a go with native ALSA.

Already 02-47 should work fine with ALSA.
Will it be so easy to delete according to "removeoss"- cmd and make/ configure once? 

No. You must install ALSA on your computer. OSS has removed it
and you must install it. Under Debian it is fairly easy,
but I can not say I remember it completely.

There is a problem however, you must install several packages
and I do not know which ones because of my bad short time memory.
you will need (probably) all of

libasound2                ALSA library
alsa-base                 ALSA driver configuration files
alsamixergui graphical soundcard mixer for ALSA soundcard driver 
(for oss mode)
alsa-oss                  ALSA wrapper for OSS applications
(for native ALSA)
libasound2-dev            ALSA library development files

Best is to install both of them so you can choose at run time.

When everything is installed, then ./configure followed by make

I would think ON5GN will know:-)

I will make test runs under several distributions once I have
02.49 working. Then I will take notes about install and de-install
problems on different systems. It may be of some interest to
check the real-time performance on different versions of
the kernel and sound drivers now that the Tx side is running
(although not quite correctly yet.) The time from a key press
until the tone reaches the head phones should not exceed 50
milliseconds or so. I have 10 ms from key-down to full power
and another about 40 ms until the tone reaches my head-phones
through the receive side. (Normally there is silence, but I
can listen while transmitting on another antenna)

Many soundcards do not allow small buffers under ALSA. I do not
know if it is different with OSS. There is a lot of time to spend
because there are many soundcards, different Linux generations
with OSS, ALSA and ALSA-OSS as well as Windows versions.
Installing different soundcards under Windows is a real pain...

Earlier tests have shown significant effects, but maybe the
code is better now so the differences between systems is less
visible. What I see is pretty close to what is theoretically
possible with the current window functions.

73

Leif
LINRADDARNIL