Hello everyone,

The info below may help in planning AO-51 operations on Wednesday and Thursday for the next few weeks.

-- 73 de JoAnne K9JKM k9jkm@amsat.org Editor, AMSAT News Service

SB SAT @ AMSAT $ANS-126.02 AO-51 Schedule Change to Accomodate New Software Testing

AMSAT News Service Bulletin 126.02

From AMSAT HQ SILVER SPRING, MD.

May 6, 2007 To All RADIO AMATEURS BID: $ANS-126.02

AMSAT Vice President of Operations, Drew Glasbrenner, KO4MA, previously announced the on-going software upgrade and ensuing testing efforts for AO-51.

During the last round of testing and upgrades on AO-51, the Command Team discovered a problem with the BBS receiver interfering with the command system with either UHF transmitter above a certain power level. This problem had gone unsolved since launch until the relationship to the receiver was found. The good news is the problem goes away when that receiver is shut off.

The bad news is that particular receiver is the only user receiver the operating system allows to access the BBS. A rewrite of the core opera- ting software is required to work around this issue, and there is exactly one person who can do this. For the mean time AO-51 will pri- marily be an analog mode satellite, until the fix is coded and tested thoroughly on the ground.

Testing aboard the satellite has started. Gould, WA4SXM, AO-51 Operations Group and Command station has updated the May 2007 AO-51 (AMSAT Echo) Schedule. Gould wrote, "We will be testing automatic mode switching on AO-51 for 2 days each week on Wed & Thur this month, except for Dayton week. The rest of the time AO-51 will be in 'normal' mode."

The first mode switch already occured on an early US east coast pass on 2 May 2007. The AO-51 schedule for May on the AMSAT web site has been updated: http://www.amsat.org/amsat-new/echo/ControlTeam.php

Enjoy these modes and send comments and requests to the AO-51 Operations Group at ao51-modes@amsat.org.

AO-51 May 2007 AO-51 (AMSAT Echo) Schedule May 1 until May 31, subject to modification

Normal mode except for 2 days testing on Wed - Fri. Testing of the automatic scheduler

2 - 4 May 2007, 9 - 11 May & 23 -25 May, no change during Dayton week, to be defined mode change the last week of the month.

2 May - 4 May Mode 7 Testing

FM Repeater, V/U Uplink: 145.920 MHz FM, NO PL Tone Downlink: 435.300 MHz FM

QRP FM Repeater, V/U Uplink: 145.880 MHz FM, NO PL Tone Downlink: 435.150 MHz FM

9 May - 11 May Mode 4 Testing (Field Day configuration)

FM Repeater, V/U Uplink: 145.920 MHz FM, NO PL Tone Downlink: 435.300 MHz FM

FM Repeater, L/U Uplink: 1268.700 MHz FM, NO PL Tone Downlink: 435.150 MHz FM

23 May - 25 May Mode 2 Testing

FM Repeater, V/S Uplink: 145.880 MHz FM, NO PL Tone Downlink: 2401.200 MHz FM

Normal Mode FM Repeater, V/U Uplink: 145.920 MHz FM, NO PL Tone Downlink: 435.300 MHz FM 9k6 Digital, V/U, Telemetry Only Downlink: 435.150 Mhz FM, 9k6 Telemetry

[ANS thanks Gould, WA4SXM for the above information]

/EX