Category: Ham Satellite news

Senaste nytt om Echo AO-51:

The remainder of this week is expected to be spent loading some new code, testing the S downlink and the UHF B TX. Note that the S downlink when in digital mode will always be at 38k4 or higher. It is not capable of 9k6 due to limitations involved in making it work properly at speeds up to 76k8. We are pleased so far with the strength of the 2.45W S downlink. At times the UHF A TX (.150) will be off or at very low power. We will also be testing
transmitters at higher data rates. Listeners should not be surprised or alarmed if the UHF A TX is not on or if they are unable to copy it at 9k6 during some orbits.

The Command Team is carefully checking off the tests and measurements that are part of the commissioning process. They ask everyone to be patient and again, AO-51 is not yet open for use. Any transmissions aimed at AO-51 by
other than command stations will slow down the process and delay the day when it is open for all to use.

The coloradosatellite.com/echo web site was off line for a few hours Sunday and Monday due to a data center move. Stations wishing to upload telemetry should find it on line now.

[ANS thanks Jim, WD0E for the above information]

Klla: ANS 195

Nu heter AMSAT Echo AMSAT-OSCAR-51, AO-51:
—
AMSAT-NA President Robin Haighton, VE3FRH has asked me to handle issuance of OSCAR numbers, and has written me requesting an OSCAR number for the Echo satellite. Therefore, in response to his communication, I hereby issue Echo the number AMSAT-OSCAR-51 (AO-51) to this exciting new amateur radio spacecraft. Thus, AO-51 joins a long line of amateur radio satellites beginning with OSCAR-1 launched in December, 1961.

I wish to congratulate everyone involved in the design, construction, testing, preparing for launch, launching and commissioning of this latest Amateur Radio spacecraft.

I trust that amateurs all over the world will have an opportunity to avail themselves of the many features offered by AO-51. May AO-51 have a long and productive life.

Best wishes and 73,
William (Bill) Tynan, W3XO

Klla: ANS

Mycket fakta om Echo AO-51 i denna notis. Fortfarande gller, snd ej till satelliten:

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.

[ANS thanks Jim, WD0E and Mike, KE4AZN for the above information]

Klla: ANS 193

Frn AMSAT-NAs hemsida:

During the last pass on 30 June 2004, the TX power was turned up to 3.1 W to assure a good downlink while continuing to load software. Unfortunately, the power could not be reset to a lower level before the pass ended. The BCR responded as expected and eventually turned off the transmitter. The transmitter will be left off for the remainder of the night to allow the batteries to fully recharge. During the 02 July morning passes over the US East Coast the transmitter will be turned on to gather telemetry and evaluate the situation.

If you have recorded any telemetry data please send both the Raw and Engineering CSV files to ke4azn@amsat.org.

[ANS thanks Jim, WD0E, for the above information]

Klla: AMSAT-NA

Frsta kontakten med Echo har nu gjorts. Telemtri har tagits emot p 435.150 MHz och sndaren lmnas p med en uteffekt p 0.3 watt. Det r allts fritt fram att lyssna!

First contact with Echo was at 1452 UTC on 29 June 2004. After collecting a bit of TLM the 435.150 MHz transmitter was turned off at 1500 UTC. The preliminary keps were observed to be pretty close. The first look at ECHO s
telemetry shows things are looking good. The battery was fully charged and the panels were delivering about 950 ma, which is fine. The panels were supporting the transmitter power adequately at about 2.3W output. The bird appears to be tumbling as expected. Internal temperatures are around
10C which is also as expected.

On the second pass the loading of software began and good progress was made. Telemetry continues to look very good. While fades clearly indicated we continue to tumble (as expected), at 2.2 Watts output we were able to make good bits without difficulty. Rather than turn the TX off at the end of that pass, based on a very good looking power system, the power was turned down to about 0.3 Watts.

The hour between passes was spent closely examining the captured telemetry and comparing it to pre-launch testing, as well as tweaking the keps a bit. At the start of the next pass the power will be turned back up and loading
the housekeeping software, a task which will continue on the evening passes tonight, will resume. The TX has been left on at about 0.3W.

If you record telemetry please send the CSV files to ke4azn@amsat.org.

Please do not transmit to Echo until checkout and commissioning has been completed and the satellite is made available for general use. Unexpected uplinks may cause delays in verifying the proper operation of ECHO and delay
the opening of the transponders to general use.
[ANS thanks Jim, WD0E, for the above information]

Klla: ANS

Kl. 06.30 UTC idag den 29/6 kom d Echo upp tillsammans med 7 andra satelliter. Satelliterna placerades i bana 30 minuter efter start. Hr kommer den officiella notisen frn ANS:

AMSAT News Service Bulletin 181.01 From AMSAT HQ
SILVER SPRING, MD. June 29, 2004
To All RADIO AMATEURS
BID: $ANS-181.01

Chuck Green, N0ADI, reported by phone from the Baikonur Cosmodrome that the launch of AMSAT Echo and the other satellites occurred on time at 6/29/2004 0630 UTC. He watched the rocket climb out and said it appeared to be flying straight and true. A second phone call from Chuck 18 minutes later confirmed that the launch carrying AMSAT OSCAR Echo was successful and that all spacecraft had separated successfully.

Chuck was assisted in the final integration and checkout process at Baikonur by the team from SpaceQuest which included Dr. Dino Lorenzini KC4YMG, Mark Kanawati N4TPY, and Lyle Johnson KK7P. The SpaceQuest team members are also AMSAT members and volunteers.

A first attempt to turn on Echo will be made during its pass over the US at about 1430 UTC. Initial transmissions will be short, just enough to gather some telemetry and analyze the performance of the power system. Those first
downlink signals will be on 435.150 MHz FM at 9600 bps.

The correct callsigns for Echo s Pacsat Broadcast Protocol Digital system are:

Broadcast: PACB-11
BBS: PACB-12

The callsigns reported in ANS-180.01 were incorrect.

A telemetry decode program, TLMEcho, is available for those who would like to view and report data from Echo. It may be downloaded from http://web.infoave.net/~mkmk518/echo.htm

If you record telemetry please send the CSV files to ke4azn@amsat.org. A database for all telemetry has been established and will be tested over the next few days. When testing is complete it will be made available for
direct upload of telemetry files as well as queries on any and all data.

Please do not transmit to Echo until checkout and commissioning has been completed and the satellite is made available for general use.

[ANS thanks Chuck, N0ADI, and Jim, WD0E, for the above information]

Klla: