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

Re: MIR SAFEX repeater







Hello All:

The SAFEX II Repeater is indirectly helping the MAREX-NA SSTV project.


The SAFEX II Repeater is connected to two (2) Out side antennas.
Each antenna is a Dual band antenna, 2meters and 70 cm.
One antenna is used for Receiving on 70cm, the other for transmitting on
70cm.

The SAFEX II Receiving antenna is attached to a Diplexor Filter, which is
INSIDE the SAFEX II Repeater.
The 70 cm side of the diplexor goes into a 70 cm notch filter, which allows
the SAFEX II receiver to be
on, while the 70 cm safex transmitter is on.  Just like a regular repeater.
The 2-meter side of the SAFEX II diplexor goes to a panel mounted SO-239
connector on the front
of the SAFEX  II repeater.
This remote port can only be used for 2-meter ONLY.
If you try to put a 70cm signal into this port, the signals will be
blocked.
This is one of the reasons why we have not moved one of the projects to
437.975.


The PMS has been using this port as its primary antenna since December
1997.

Today, the PMS and the SSTV are sharing the same antenna port (one at a
time).
The SAFEX II is still panel mounted in the equipment rack of the Perioida
module.
The Antenna connections into the SAFEX Repeater have not been
moved/changed.
The Original PMS antenna is located in the Mir-core module.  The old pms
antenna broke
in December 1997, which is why the PMS was moved.
A new antenna has been installed on the Mir-core for 2meter and 70 cm,
however the pms
has not been moved back to the Mir-core at this time.
If the future, if the crew has space and time, the pms and SSTV may be
moved to a different location.


Status of SAFEX II Repeater.
The repeater has 4 problems.
1.  Low AF Audio, crew could not hear anyone unless they put their ear on
the SAFEX II speaker.
2. Repeater jumps out of Voice mode into Repeater mode intermittently.
This could be caused
by a power dip.  This caused a few school schedule problems.  The Mir crew
would be talking
to a school on the voice channel, and the repeater would jump to the
repeater channel.
3. Oscillation on the downlink from repeater.
4. Intermittent lockup during the power on boot.

Problem #1 is not serious, and the repeater can be used in repeater mode.
But can not be used for two way voice with crew.

Problem #3 prevents any usable audio on the down link of the repeater.
Since the PMS is feeding a third harmonic signal into the SAFEX II Antenna
port, it could have
been causing problems 2 and 3.  We have never had time to test this theory.
The SAFEX II repeater has an auxiliary 12 VDC connector on the front of the
radio.
This power source has never been used by PMS or the SSTV.
Both the PMS and SSTV are sharing one stand-alone 150 watt power supply.

Problem #4 has been seen on Mir and on the test system in Russia.  This is
a minor problem and will
usually go away after several reboots.

When the crew have time, we hope to test the SAFEX II Repeater, while the
PMS is turned off to see
if the Oscillation problems go away.  No date has been scheduled



Miles MAREX-NA







McGrane <tmcgrane@suffolk.lib.ny.us> on 01/02/99 01:05:15 PM

To:   sarex@AMSAT.Org
cc:    (bcc: Miles Mann/PicTel)
Subject:  [sarex] MIR SAFEX repeater





Hi all-

I got the impression SAFEX repeater equipment was used for SSTV.

Please correct me if I'm wrong. ( nicely hi hi )

What is involved with getting it back on and operating.

Bear with me but I enjoy talking on a radio more than just monitoring.

Those who know what can be done please answer via reflector.

HAPPY 1999 to all, pat N2OEQ  Long Island New York.


----
Via the sarex mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe sarex" to Majordomo@amsat.org




----
Via the sarex mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe sarex" to Majordomo@amsat.org



AMSAT Top AMSAT Home