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Hello Wolf,
reading this message pushed me to check my netbook
(a dot s from PackardBell) and surpise! in the properties I found that I could
change the SR up to 192kHz!!!
So I tried and it works but.....
- although I can axtend the reception till 90 kHz,
above 40 kHz the sensitivity falls (MDS is around -45÷50 dBm)
- when using SR above 48 kHz the calibration of SR
doesn't work (even when the reference signal is in the good reception band) or
using a 10 kHz external reference.
Anyway is ever a good idea to explore the
capabilities, and this is a good occasion to wish to the group an Happy New
Year!
73 de Marco, IK1HSS
----- Original Message -----
Sent: Sunday, December 29, 2013 6:50
PM
Subject: Re: LF: VLF exciter / signal
generation in Spectrum Lab
Hi Graham,
About 74 kHz reception: I
recently discovered that a Lenovo 'X61s' netbook, bought cheaply at a rally,
supports true 192 kHz sampling with the onboard 'soundcard' (once one
discovers where to configure that in the swamped windows 7 system control, or
wherever they decided to put the soundcard control dialog today. IIRC it was
"Properties of Microphone", translated from german into english).
Indeed
the usable 'audio' range covers a few Hz to 96 kHz ! This would allow direct
reception on 74 kHz, and also using DCF77, MSF, or similar time signal
transmitters as reference for the sample rate correction... SL could
translate down into the audible range, and downsample to 48 or 24 kS/second,
before sending the converted signal to other applications.
Anyway it
would be much easier if the "hard coded frequency range" would simply be
removed from the original Opera software, and completely leave it to the human
operator to enter the frequency range in a simple input
field.
73,
Wolf .
Am 29.12.2013 18:56, schrieb
Graham:
Thanks Wolf,
With the 8K signals out side the Op decoder ,
some users wanted to monitor the test ,
but needed a way of changing the qrg
slightly to match ,
The other thing , that occurred to me
, was the other 75 K stations , may have a TA
chance using Op4H , +6 dB gain over op1H in
the 'window' time , may be 1 run or
2 max ? ... recovering the 8K audio may
be a problem , my ra6790gm has a locked
bfo range of +/- 19KHz or so , but
, for normal ssb-rx , then a shift up
from 1500 would be needed [ may even catch Bob
on 4H hihi]
73-G,
Sent: Sunday, December 29, 2013 1:25 PM
Subject: Re: LF: VLF exciter / signal generation in Spectrum
Lab
Hello Graham,
Am 29.12.2013 14:04, schrieb
Graham:
Wolf,
Q How to configure SL as audio
frequency changer ?
say 1500 Hz to 8 KHz , or , 8100 to
8200 etc
how is the set up ?
The
easiest way is using the 'narrowband filter', which can also shift
frequencies.
Start by selecting 'Quick Settings' in the menu, then
'Other amateur radio modes', 'Narrow CW filter with adjustable xyz'. You can
see the filter's passband on the main frequency scale, along with the 'zero
beat' indicator similar to a web sdr. Grab the passband widh the mouse and
move it to the 'source' frequency range. Alternatively, enter the frequency
shift in numeric form on the filter control panel. Details:
http://www.qsl.net/dl4yhf/speclab/filters.htm#filter_controls_on_main_freq_scale
will SL appeared as a sound source
? It can, but unfortunately only as an ASIO device.
Microsoft's ever-changing driver model is so utterly complex that I gave up
writing my own 'multimedia driver'. Also I didn't feel like re-inventing the
wheel for XP, Vista, Win7, Win8, and whatever-comes-next... :o)
Thus the easiest (??) method would be to use Virtual Audio Cable.
The
more complex (but VAC-less) way, if ASIO is supported by the audio-receiving
application, is decribed in the 'Audio I/O' manual:
http://www.qsl.net/dl4yhf/AudioIO/AudioIO_Manual.pdf
The
relevant chapter would be "Installation of in_AudioIO.dll as an ASIO
device".
Now back to the soldering iron..
73,
Wolf .
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