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Re: msg



On Fri, 13 Sep 2002, Nagesh wrote:> Amsat-India:

> ========= vusat will carry a message beacon which will playback on
> command, pre-recorded voice message... Hereby we want to invite your
> ideas regarding the message/s. Think of short, crisp, meaningful,
> attractive messages of duration 15secs.

In addition to VOICE, I would suggest two other recorded message types.
One is a PACKET BULLETIN which can be read by anyone using a standard
AX.25 packet program.  In 15 seconds of audio, you can include almost 1.5K
of text.

Also, include a PSK-31 audio file.  In 15 seconds of audio, you can
include over 30 streams of text.  Each stream can have about one line of
text in it.

I tested one of the cheap $10 audio record-playback chips that can be
purchased in a common greeting card.  I recorded PSK-31 and it played
back just fine.  I ran this simple system on 10 meters for a few months
and had  stations 10,000 miles away using it...

You would need to test the AX.25 packet to see if it worked, but if it did
not work at 1200 baud, it might work fine at 300 baud using the 200 HZ
shift as used on HF.

These two pre-recorded AUDIO messages would give some interesting variety
to your project.  For the PACKET message, be sure it is in APRS BULLETIN
format so that the thousands of APRS radios can receive the text directly
on their front panel.  Since the PACKET audio file can contain about 15
lines of text, I would suggest somthing like the following:

VUSAT>CQ::BLN1VUSAT:Welcome to AMSAT INDIA's automatic voice playback system.
                    These messages

VUSAT>CQ::BLN2VUSAT:were contributed to this project for transmission
                    around the world.

VUSAT>CQ::BLN3VUSAT:The next packet in this file will be an APRS object
                    packet which

VUSAT>CQ::BLN4VUSAT:will appear as a crown jewel over India, marking our
                    first AMSAT to space.

VUSAT>CQ:)NAMEHERE!DDHHMM.hhN/DDDMM.HHEE...comment goes here

Notice that the actual APRS ICON used is the large EYEBALL and that it can
be placed anywhere in India.  Maybe your school, or the capital, or your
launch site?.  Also it can have a 9 character NAME and a COMMENT
associated with it...

Anyway, just some ideas to think about...  Of course it all depends on the
quality of your audio recording and play back system as to whether these
messages can be decoded..

de Wb4APR, Bob


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