[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: MIR transmits UNUSEFUL data !

To me, It's still a great deal of fun to even copy a LEO station like Mir
or any other satellite. What do you expect ? There is not enough time to
send any usefull data. A quick Hi and Bye is good enough for most people
considering what we have to work with. Wait for Phase 3D. There will be
plenty of time to send usefull data on that bird. What is usefull data
anyway ? This is only a hobby after all.

From: Alain De Carolis <alain@mdcom.it>
To: sarex@AMSAT.org; amsat-bb@AMSAT.org
Subject: MIR transmits UNUSEFUL data !
Date: Friday, June 19, 1998 11:18 AM

Dear OM's,

I would like to say my point of view about the MIR voice/packet operations.

MIR, as everyone on this list knows, operates on 145.985 FM. Packet is 1200
Bd AFSK AX.25.
With this configuration MIR is very easy to work because the needed
equipment is very poor:  WRONG !!!

Give a see at the attached file. It is the monitor window of last MIR pass
over Europe.
Well i have counted 140 BUSY flags on 160 packets received!
This means that about 87% of the data trasmitted by MIR in a entire pass is
totally UNUSEFUL.
Noone were able to read or send a message (so what is the goal of that pms
up there?).

For who does not know what a busy means (I think that only very few people
know it when i look at the monitor window...) it means that when you
a "Busy fm R0MIR-1" it wants to tell you this: "I am BUSY at the moment,
could you please stand-by and wait for your turn?". People seems to ignore
this and immediately call again. Then, of course, they get again busy, so
they try again and so on.

The pass I have just recorded is not the worse. In fact the R0MIR
was turned off. When the digi is ON there are all the neighbourhood
saying "hello" and "how are you" to each other so the unuseful data sent
rate is close to 100%.

Voice operations are also difficult over high populated areas. In fact, for
example, just few days before coming back Andy Thomas wrote: VOICE HAS BEEN
Many of the cosmonauts do not like to the amateur radio on voice because of
the confusion wich immediately starts. They just like to have a chat, not
manage a vk0ir-like pile-up.


The idea that a easy access station onboard MIR allows all amateurs to work
it is wrong. In fact currently only few amateurs have enought antenna gain
and enought power to pass over the "QRM" and work without problems R0MIR.
MIR is going to be destroyed in a short time. So it's too late to think
about any change.
We must think about the new ISS. I believe that a too popular amateur radio
system is not a right choice. A
less accessible one (eg. packet PSK and phone on UHF) would allow all the
really interested hams to work the space station easily, and would cut off
all the "just courious" and the trouble makers.

Please let me know what is your impressions about this. Best 73's

Alain De Carolis IZ6BYY (ex IW6PBC)
e-mail iz6byy@amsat.org or alain@mdcom.it
home page http://users.mdcom.it/alain
ICQ UIN 1870256 - PGP Public key avaiable
GSM phone +393388719952