[PCR-1000] weather satellite help

[pcr-1000@mailman.qth.net]

In a message dated 01/25/03 12:09:13 PM Eastern Standard Time, 
direland@drdale.com writes:

> Hi
>  I have wondered the same thing. I use the speaker output and seem to get 
the
>  maximum resolution available. What advantage would the packet provide. I
>  don't know the differences between the two outputs.

Hi Dale and All...

The Packet output is typically taken from the Discriminator circuit of the 
receiver prior to any amplification.  Audio amplifiers are designed different 
ways and some "shape" the signal with "de-emphasis" or otherise limit the 
audio range to put most of the audio response in the middle of the typical 
"hearing range" of most people so that the signal seems "clearer" to your 
ears.

In data communications we do not care what our "ears" hear but want the 
optimum frequency response at the data audio frequencies. By picking up the 
audio before it is amplified we have "pure" audio output not mucked with by 
the amplifiers.

Perhaps the PCR-1000 has good frequency response for the WXSAT tones through 
the amplifier and it makes little difference which output you choose....I 
have found very little difference myself but have never looked at the actual 
waveforms with a scope.

It could however be that in some other data mode the amplifiers have poor 
audio response and the "packet" or "data" output is available for and should 
be used there.

Just be aware that it is "poor practice" to take a Amplified output and drive 
a line input with it.  As has been pointed out, the PCR-1000 SEEMS to have a 
low enough
audio output so that you will not damage your Soundcard input, however be 
very careful of loading the line input of your soundcard with "Watts" of 
audio power as from a stereo or radio or other type of output which is 
amplified to speaker level.

Otherwise Enjoy the Sats and keep an eye out for an announcement of SSTV from 
ISS which will also be accessable via soundcard.

BST DX

Roger
WA1KAT