[HamSat] Echo Status

[Timothy Pickett]

AO-51 ECHO
Catalog number: 28375
Launch date: June 29, 2004

Status: Commissioning

Please DO NOT Transmit to the satellite - commissioning must take
priority. A bulletin will be released when the satellite is open for general
use.

Analog voice downlink:  435.225 MHz FM
Analog voice uplink:    145.920 MHz FM 67Hz PL tone

Digital 9600 bps AX25 PACSAT Protocol Mailbox

Digital downlink:  435.150 MHz FM
Digital uplink:    145.860 MHz FM

ECHO Experimenters Day Operation Wednesdays (UTC) 00:00  23:59
Default configuration will be:

Digital downlink:  2401.200 MHz  38.4 kbps FM
Digital uplink:    1268.700 MHz   9600 bps FM
1268.700 MHz uplink 9600 bps FM

The ECHO Operations committee will determine modes and schedules for
experiments.

July 6, 2004

On the 06 July 2004, during the 0310 UTC pass, the SQRX was set to a VHF
frequency and the antenna relay switched to the VHF whip.  Once the various
modulator/switch functions where set to the right configuration the SQRX
audio path proved to work fine.  In an additional test of the SQRX the
receiver was retuned to an L-band frequency and connected to the L-band
antenna on the bottom of AO-51.

Testing has also been done on S-band using a frequency of 2401.200
MHz.  The second 70cm transmitter has also been tested as well as the
ability to command frequency changes to the transmitters should that be
needed in the future.  All transmitters have been confirmed to be
operational.

Friday, 09 July 2004 the 38k4 digital downlink was enabled for the first
time on the UHF A transmitter.  Mike was able to copy packets at 38k4.
Further testing will be done, and some WOD data will be downloaded at 38k4.
The modulator settings for that mode will need to be tweaked as testing
continues.

Mike, KE4AZN has taken some WOD data at 3 second intervals during daylight
passes over his station to get a better look at the satellite's attitude.
That data is being analyzed.  When AO-51 is not in view of the command
stations, WOD at 30 second intervals is gathered continuously during the
period from the time last time they see the satellite after a group of
passes until their next AOS.

The EDAC count in Echo is not counting the actual number of physical memory
errors, but the number of times the software detects a memory error while it
is running.  If the software loops through that section of memory a number
of times before the error is cleared, the EDAC count will increase by a
large value.  There is a routine that runs on a specific time interval to
"wash" memory and clear any errors.  Until that routine runs, if the program
loops through that memory area, it will count an EDAC error.

With the file system now running, the downlink is going to show the BBS is
open even though the BBS has NOT been made available for general use.
Everyone is requested to please not transmit to ECHO until checkout and
commissioning has been completed. Unexpected uplinks may cause delays in
verifying the proper operation of ECHO and delay the opening of the
transponders to general use.

The commissioning and checkout activities are going very well.  During this
checkout period activities and plans are very dynamic and frequent mode and
transmitter changes should be expected.