[VWS] AX.25 question

[Tom Azlin, N4ZPT]

Hi Ester,

Hi Esther,


A bunch of us around here are familiar with AX.25. The wiki has a good
description, but it should be easy for us to help you get up an on the
air with AX.25 to get some experience.

I am guessing that Thomas Jefferson High School wants to incorporate a
packet simplex repeater (aka digipeater) in your planned satellite. Most
of AX.25 TNC) will digipeat AX.25.  So setting up a packet node would
give you a packet repeater.  I do not know what your space and power
budget will be.  Nor what your ability put deploy antennas will be.

A packet node is a transceiver with a TNC.  Many TNCs have small
bulletin boards (BBS) in them so there would not need to be a computer
connected. (not as interesting then but it works). The Space Station
sometimes has their VHF radio running in Packet mode as a digipeater and
has the BBS running. Once you get a TNC to play with you might set up
your club station to listen on a good mid-pass frequency (remember
Doppler) when the orbital predictions say to listen.

Does TJ's club have a TNC? I have a spare one the club can have to play
with.   And there are some small ones that might be ok for your satellite.

Terry Fox, an AMRAD Club member, was the AX.25 standard author.  He is
not currently in the area but does come up here from time to time.  Mark
Kanawati, another AMRAD member, is involved in Satellites. He might also
be able to help your TJ team.  I have also cc'd the AMRAD reflector just
in case Terry or Mark are not able to respond right away. Perhaps folks
can reply direct to you Esther.

One of the Amateur satellites in orbit was put together by AMRAD.  So
they are a possible resource for your TJ project.

73, Tom Azlin N4ZPT



HaoQi Li wrote:
> Does anybody know about AX.25 (http://en.wikipedia.org/wiki/AX.25)?  We're
> trying to incorporate a repeater function for the satellite project.
> However, we are confused about how to use AX.25 exactly.
> Thanks for any help.
> Esther
>