Re: [linrad] Linrd installation...a few comments

["Arie Dogterom" <pa0ez@xxxxxxxxxxxxx]

Rein,
I played with kmix and even with that programme I can mute the input ( in my
case mic) and by controlling "IGain" I can set the recording level. Mic is
set for recording and if you want to hear what you are recording you of
course can unmute the mic channel and set the audio level.
But for linrad you have to mute the mic channel and use the Igain for the
input recording level. Then linrad runs without the signal bypassing linrad.

note : It is a pity that on my laptop the only input is mic, which is mono.
Line in is not  accessible from the outside. I probably have to find it
somewhere on the motherboard.
73
Arie

----- Original Message -----
From: Rein A. Smit <rein0zn@xxxxxxxxxxxxx>
To: <linrad@xxxxxxxxxxxxxxxxxxxxxx>
Sent: Tuesday, May 20, 2003 1:22 PM
Subject: Re: [linrad] Linrd installation...a few comments


>
>
> Hello Arie,
>
>
> Glad to hear from you and thanks.
>
> Let me go back, I have the MIC un-muted, connected and hear the signal,
> see the spectrum on the spectrum analyser display from my source.
> This is running via "capture"
> Then I select "record" see the .wax file building.
> That is all fine, actually I got that with Linrad the first time
> I installed it. ( source audio in freq/waterfall )
> Gain, base line adjustment are working, average FFT, parameter is
> all responding again with just the standard Mandrake installation
>
> Then I decide to play back:
>
> The stored audio is being played back and I see it on de spectrum
> display via "capture" if I remember well fine. previously recorded audio
> but if I do not mute the miKe or turn the receiver output down, I also
> get the the receiver real time audio in the audio output
>
> I assumed that if I would play back that the input channel would be
> muted by Krecord. Isn't that the logic thing to do?
>
> Anyway it does not do that i  y case at least! Then I also  assume
> that linrad switches in the software between sampling from the input
> ( mic or what ever ) and output from the processed software.
> Of course real audio should never end up in the audio output channel.
> As a matter of fact the sound card should be set up for this routing
> when you start Linrad and remain like that ( IE NO switching during
> acquisition / display )
>
>    Repeat for Krecord:
>
>   input sample -> DAC, ETC ( MIC ON/Off ) LINRAD Processing
>   ( PCM ON/OFF  )->  DAC, ERT - > output sample -> Volume out.
>
> I assumed that Krecord would provided for MIC OFF/ON and PCM ON/OFF
> as part of the "manual"  record/display selection,
>
> Is that true, ie should the be mic channel  be manually turned of
> or not. I would think not!
>
> In linrad their is no playing of the raw input audio.
> However the audio section needs to be permanently connected
> to the processed digital audio from LINRAD via PCM and the input needs
> to be permanently connected to the digitizing part of the sound card
> but NOT to the audio section ( analog signal )  That is what is failing.
> but Krecord seems partially do this switching in my case.
>
> Have you had time to review the mute/slider functions in your Alsa-
> mixer vs what I sent you from my alsamixer.
>
> Have you any new thoughts about the channel selection issue in
> your alsamixer vs the lack off that function all together in my
> version/installed version.
>
> I am going to be in Odense next week for a few days and later in
> Oxford for work. I am not sure I can make it to Holland. Could you
> email me your phone number direct? I would like to talk to you
> live for a little bit at least.
>
> BTW Last night I could not even get into Matt's domain URL
>
> 73 Rein
>
>
>
>
> Arie Dogterom wrote:
> >
> > Rein,
> > You should mute the input channel and activate capture. Then you will
see at
> > krecord level indicator that there is a recording signal while you do
not
> > hear it. Then running krecord to play it back( goes via the pcm channel)
you
> > should hear the recording. Is that ok, stop krecord and run linrad. Foor
> > sure you then only will hear linrad processed sounds
> > 73
> > Arie
> >
> > ----- Original Message -----
> > From: Rein A. Smit <rein0zn@xxxxxxxxxxxxx>
> > To: <linrad@xxxxxxxxxxxxxxxxxxxxxx>
> > Sent: Tuesday, May 20, 2003 6:01 AM
> > Subject: Re: [linrad] Linrd installation...a few comments
> >
> > >
> > >     Hi John
> > >
> > >     What is it, you mean by cheaper onboard sound cards?
> > >     PCI stuff in particular. There have been issues with sound
> > >     cards all the way back to FFTDSP by Af9Y and plenty of DSP
> > >     programs being sensitive to the type of sound cards being
> > >     Some of them wanted 8 bit cards. I type this on a WIN95
> > >     machine with a 8 bit card installed. FFTDSP, DSPBlaster
> > >     run fine under DOS.
> > >
> > >     I suppose you are talking about the price of the mother board
> > >     to a certain extent.
> > >     Though it would be hard to detect any correlation in the final
> > >     price of the mother board and the sound section.
> > >     I have quite a few questions about this sound thing here.
> > >     Just for the fun, I will research the expensive boards and what
they
> > >     use for onboard audio systems. (  ASUS et al )
> > >     I have questioned myself whether there is actually a problem with
> > >     that sound section. However it does everything in WIN98SE and as
> > >     a matter of fact in Linux as well .
> > >     It is also working with this krecord program using .wav files
> > >     In that mode however the mic/line inputs are not being muted.
> > >     it is not a matter of cross talk, the mic signal passes through
> > >     un-attenuated  This krecord is neat, you can listen to signals
> > >     record them in memory and play them back, in my case I have to
> > >     turn down the audio from the receiver.
> > >
> > >     PA0SE has the same audio section running on a laptop and running
> > >     Linrad. The real strange point is that the alsamixer that he is
> > >     using from alsa_utils-0.9.3 has the ability to select channels and
> > >     allows for path switching/selection and I have nothing of that
> > >     in my installation, as if the mixer adjusts itself to who knows
> > >     what! The usual volume controls, MIC,LINE, Capture, PCM and
> > >     MASTER work OK.
> > >
> > >     I have been trying to find useful info and there are hundreds
> > >     of messages of people asking/reporting about that section but
> > >     it are always problems about no sound at all, distorted sound,
> > >     low volume etc. I have nothing of that as long as I do not try
> > >     to get Linrads output. Also Linrad reports the card properly
> > >     detected and working when I go to the set-up.
> > >     Do you have Linrad running? If so perhaps you could run through
> > >
> > >     http://www.nitehawk.com/linrad_dat/
> > >
> > >     Nothing BEATS information from users with a working setup.
> > >
> > >     73 Rein, PA0ZN
> > >
> > >
> > >
> > > "John Harrison, NI1B" wrote:
> > > >
> > > > Hi All,
> > > >
> > > >    A couple of comments about getting a useful Linrad setup.
> > > >
> > > >    MANY of the recent on-board and cheaper internal PCI cards have
GROSS
> > > > problems.
> > > >
> > > >    In two cases (one on board and one add on card) the card had NO
> > > > anti-aliasing filter (at all). The card would pick up high frequency
> > > > signals and noise and fold it over into the lower freqs with NO
> > > > attenuation !!
> > > >
> > > >    In the other PCI case, the card was apparently very slow in
taking
> > > > samples so virtually NO TIME was left for Linrad :(
> > > >
> > > >    ALL of the ISA cards I have tried have had neither of these
problems,
> > > > but try to find a recent motherboard with an ISA slot!!
> > > >
> > > >    Anyways just another two technical details to check for when you
are
> > > > selecting a sound card.
> > > >
> > > >    warm regards,
> > > >    john, ni1b
> > >
>



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