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Re: uo-36 tnc's



>
> What will you do if we end up with satellites on 38k4, 76.8 and 153k6?
Will
> you switch between 3 IFD boards or just use the fillers for 153k6. Doing
so
> will require 6 db more gain in your ground antennas than you really need
for
> 38k4.

I think at that point, we should consider an autobauding TNC and leave the
IFD
opened up at 153k6.

>
> Are the large Oscar antennas that much of an over kill for 38k4?
>
I would also think that would depend on the satellite.. If orbits decay and
the
spacecraft begins to loose station keeping (IE: AO-10/AO-13) after years of
service you would need higher gain antennas to compensate.

> What are the smallest gain antenna needed for UO-36 at 38k4?
>
> The other limitation is the connection speed between the TNC and the
computer.
> I have used a  PacComm  Spirit-2 to receive 38k4 from UO-36 but its top
RS-232
> speed is 57.6 kb.  The top speed of the Symek TNC3S is 115.3 kb.  I think
> that a satellite using the PacSat broadcast protocol with 153k6 downlink
> would overrun
> the TNC to computer link.
> You could use the option on the TNC3S to use the serial port not as a
RS-232
> port but as a link to a HDLC card in the PC. If you have such a card then
it is
> just as easy to attach the modem cards direct to it and skip the TNC.  In
any
> case I do not believe that WISP supports a HDLC card.

A better solution would be to either run it Ethernet, USB or Parallel port..
Parallel port devices can transfer data at 230kb/sec so that should be more
than
sufficient for future devices.


What i would like to see is a spacecraft to spacecraft linking system when
satellites
are co-visible that they have the ability to transfer data between each
other.  It would require
very little power since the crafts are flying past each other and just
exchange data kept on
the PBBS.   Then again I would like to bounce lasers off the moon for
communications but
I'm dreaming for a long time there..


73's de Don - WL7NF

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