An uneventful time for OSCAR-11. During the period May 15 to 09 June<BR>2001 reasonable signals have been received from the 145 MHz. beacon.<P>The battery voltage observed during daylight passes has continued to<BR>decrease. The average value observed was 13.3 with a range of 13.1 to<BR>13.5 volts.<P>The internal temperatures have continued to decrease by a further one<BR>degree C. They are now -0.2C and -1.6C for battery and telemetry<BR>electronics respectively.<P>The WOD survey of channels 1, 2, 3, 61 (X, Z, Y magnetometers and<BR>status) dated 24 March, has been transmitted. This WOD may now been<BR>downloaded from my web site (details below).<P>The magnetometer calibrations have steadily changed during the many<BR>years in orbit. Although the changes are small and are not noticeable<BR>on a plot of individual channels, they do have a considerable effect<BR>when the total magnetic field is calculated. UoS has recently<BR>supplied some new calibrations, which give a good match when used<BR>with the current WOD. I have now posted them on my website, in the<BR>'UPDATES' page.<P>The spin period has varied between 300 and 344 seconds, with the<BR>attitude control working normally. During this period there have been<BR>279 Z, one Spin+, and 111 spin- counts.<P>The mode-S beacon has been heard by Shlomo 4X1AS, Bob K6WL, and Neil<BR>G4HLX. Shlomo reports S3 signals with a modified Drake converter,<BR>and G3RUH 60 cm dish. Bob uses an SSB converter with a 16 dB<BR>parabolic antenna. Signals are 3-7 dB above the noise. Neil uses a<BR>Drake converter with minimum modifications and a 16 turn RHCP helix.<BR>Signals are just above the noise. Many thanks for those reports.<P>Users of OSCAR-11 should note that the hardware generated time in the<BR>ASCII telemetry is now 15.5 minutes ahead of UTC, and the date is<BR>three days advanced. Unfortunately these errors cannot be corrected.<BR>There are also smaller errors in the software generated times,<BR>advances of 3.5 in the status blocks, and 1.5 minutes in the binary<BR>packets, which ground control should be able to correct. The dates in<BR>the status blocks and binary packets are correct.<P>The operating schedule is unchanged.<P> ASCII status (210 seconds)<BR> ASCII bulletin (60 seconds)<BR> BINARY SEU (30 seconds)<BR> ASCII TLM (90 seconds)<BR> ASCII WOD (120 seconds)<BR> ASCII bulletin (60 seconds)<BR> BINARY ENG (30 seconds)<P>The ASCII bulletin (number 115) is currently a static message,<BR>detailing modes and frequencies of all the amateur radio satellites.<P>There are additional status blocks after each bulletin is<BR>transmitted, and between ASCII TLM and WOD.<P>The mode-S beacon is ON, transmitting an unmodulated carrier, but<BR>telemetry indicates that it has partially failed, and delivering half<BR>power. This beacon is a useful test source for those testing mode-S<BR>converters, as an alternative to OSCAR-40. However the signals are<BR>very weak, and there is a lot of Doppler. Users should also note that<BR>the polarisation of OSCAR-11 is LHC. Even if you can't hear OSCAR-11,<BR>your equipment may still be OK for OSCAR-40 when commissioning is<BR>complete. Any reports of reception on 2401 MHz. would be most<BR>welcome. Please e-mail g3cwv@amsat.org.<P>The 435.025 MHz. beacon is normally OFF. However it can sometimes be<BR>heard when the satellite is being commanded by ground control, ie.<BR>within range of Guildford, UK. When the 435 beacon is transmitting,<BR>the 145 beacon is normally OFF. The data transmitted is mainly<BR>binary.<P>Listeners to OSCAR-11 may be interested in visiting my web site. The<BR>web site contains details of hardware required and some software for<BR>capturing data, and decoding ASCII telemetry and WOD. There is an<BR>archive of raw data (mainly WOD) for analysis, which is continually<BR>being expanded, as new data is captured. Also included are some<BR>audio files, examples of each type of data transmitted by OSCAR-11,<BR>each one plays for about ten seconds. There are also examples of<BR>mode-S reception. All the audio files are zipped, so that they can<BR>be played off-line. These should help listeners identify the various<BR>types of data, and give an indication of the signal quality required<BR>for successful decoding.<P>The URL is -<P> <A HREF="http://www.users.zetnet.co.uk/clivew/" TARGET=_blank>http://www.users.zetnet.co.uk/clivew/</A> <P>If you place this bulletin on a terrestrial packet network, please<BR>use the bulletin identifier $BID:U2RPT62.CWV, to prevent duplication.<P>73 Clive G3CWV g3cwv@amsat.org