[PCR-1000] packet output

Wed, 29 Jan 2003 11:54:37 +0200

Thanks for the info 
great explanation

-----Original Message-----
From: Brian Winter [mailto:[email protected]]
Sent: Monday, January 27, 2003 2:27 PM
To: [email protected]
Subject: Re: [PCR-1000] packet output

> 1. Should i connect to the packet output for recording the Satellites?

either should work well enough. try both.  the important thing to note is
that, whichever you use you don't overdrive the analog input to your audio
card or later stages so that clipping distorts the audio before you sample
it and save digital representation to file.

as you want to use 11k sampling rate the highest freq component that you
will record is half that (5.5khz says nyquist).  in a non-scientific way
think of the sound quality you get from your telephone (highest freq 3.4khz)
and from your hi-fi (for simplicty limited by your hearing - around 10k or
so if youre young and havn't blown your eardrums away with Black Sabbath or
Eminem)    Now imagine what your pcr100/1000 sounds like when you connect
speaker outpu into your sound card "Line In" and play a wide FM broadcast
station back through decent speakers - much better than your telephone right
?    So this setup should be all you need to satisfy 11 khz sampling rate as
long as the signal is 1) loud enough to satisfy the sampler  2)not corrupted
by overdriving the sampler.  I reckon theres more mileage in getting th
elevels right than worrying about which output gives best response.

> 2. is the a program that converts from different audio formats? yesterday
i
> finally got a good signal from NOAA17 but  i recorded it with the default
> talkpcr audio CODEC in order to decode it i need to convert it to PMC
11Khz
> mono are there any conversion programs for this?

Path of least effort: wait 'til tomorrow and try again.  i suspect the
default you used is a windows (not talkpcr) defalt.   if the sampling rate
is too slow on the original recording you cant properly recreate the bits
that are missing to give you a 11k sampled file.  If its slightly faster (eg
to x2) your 11k file will be full of sampling errors, resulting in noisy
pictures.  If you have used a compression technique (codec) you will also
introduce noise in the decompress/compress process.  Think of it like old
fashioned analog audio tape recorders. Best you record the original than
re-record a mates recording (even with Dolby compreesion techniques).

hope this is helpful
bw

_________________________________________________________________
PCR-1000 Mailing List
Post Address: [email protected]
Subscribe / Unsubscribe: 
http://mailman.qth.net/mailman/listinfo/pcr-1000
Mailman FAQ and Users Guide
http://mailman.qth.net/faq.htm