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Re: Brief msgs via 9600 Pacsats?



On Thu, 22 Oct 1998, al lawler wrote:

>   1)  Operating the pacsats without some form of doppler control is
>       virtually pointless for anything other than quick demonstrations.

Or essential critical communications if you have no other means to
communicate.  I am not proposing this for routine operations.  But trying
to see if the radio is useful for rare, but necessary commmunications in
remote areas with no other alternatives.

With the IF bandwidth of the Kenwood HT, It works perfectly with just
three settings, +5, 0 and -5.  Relatively easy to do in an 8 minutes.

>   2)  Running half duplex, it sounds like you could possibly
>       miss lots of 'ack' messages, thus causing a lot of 
>       needless resends.  This doesn't really seem all that
>       friendly to the other users, particularly given
>       how congested the 9600 bps birds can be.  

No intention to do so.  The question was asked, and the answers confirm it
is not possible.  Thanks.  We're learning...

>   3)  The pacsats have no "list mine" function.  Without a complete
>       directory, you wouldn't even know if a message for you existed. 

This is a good point.  THanks.   Any work around ideas?

I do assume that a hiker or boater or other station needing to access
the Pacsat would listen the entire pass.  But then if he doesnt listen
every pass, then he is not building up the directory.  Hummh.  Lets say he
only checked in once a day.  About how many directory entries are there on
average per day? 

I do see that his directory fill requests does add bandwidth if we assume
that all the other operators are running automatic and get the directory
piecemeal.  His Dir request would be larger than the others...

That would be a nice statistic to know  in general anyway.  What are the
operational habits of most stations?  Automatic/every pass/every day?

I noticed that only 5% or less of the PACSAT messages were to/from USA
callsigns.  Is this true in general or was this unusual for the few passes
I have worked so far?

Still learning.  Thanks

de WB4APR, Bob



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