Category: Ham Satellite news

There has been a high level of mail in recent days re: hearing AO-40.Readers of the amsat-bb should be aware from Stacey W4SM s recent posts that AO-40 has now entered a drifting phase.

The information below (prepared by W4SM) details the predicted behaviour of AO-40 through to the middle of May.

Please note the information is on a day by day basis, not orbit by orbit.

The information is presented to assist those who are fine tuning their gear,collecting telemetry etc.

On the subject of telemetry collection the norm for 100% OK blocks is for Squint angles, 0 to 36 and 60 to 70 degrees.

I mention norm, because the above ranges of squint angles apply when the Alon/Alat are nominally 0/0.

However during the drifting phase the norm no longer applies, specially in respect to the side lobe at squint 60 to 70 degree. Good reception of telemetry is available in the 50 to 70 degree range, but is range dependent.

There are lots of positives that can be gained during this drifting phase.Every block of telemetry forwarded to ao40-archive@amsat.org is greatlyappreciated.

Colin VK5HI (AO-40 Command Team Member)

AO-40 ATTITUDE – PRECESSION BEHAVIOR / W4SM
Mystery Effect = -17.760 degs ALON/week

DATE ALON ALAT SA
2003 Apr 22 [Tue] 31.0 21.8 -36.6
2003 Apr 23 [Wed] 28.3 21.8 -38.9
2003 Apr 24 [Thu] 25.6 21.8 -41.0
2003 Apr 25 [Fri] 22.9 21.9 -43.0
2003 Apr 26 [Sat] 20.2 21.9 -44.8
2003 Apr 27 [Sun] 17.5 21.9 -46.4
2003 Apr 28 [Mon] 14.8 21.9 -47.8
2003 Apr 29 [Tue] 12.1 22.0 -49.0
2003 Apr 30 [Wed] 9.4 22.0 -49.9
2003 May 01 [Thu] 6.7 22.0 -50.5
2003 May 02 [Fri] 4.0 22.0 -50.8
2003 May 03 [Sat] 1.3 22.1 -50.9
2003 May 04 [Sun] 358.6 22.1 -50.6
2003 May 05 [Mon] 355.9 22.1 -50.0
2003 May 06 [Tue] 353.2 22.1 -49.2
2003 May 07 [Wed] 350.5 22.2 -48.0
2003 May 08 [Thu] 347.8 22.2 -46.7
2003 May 09 [Fri] 345.1 22.2 -45.1
2003 May 10 [Sat] 342.4 22.2 -43.3
2003 May 11 [Sun] 339.7 22.2 -41.3
2003 May 12 [Mon] 337.0 22.3 -39.2
2003 May 13 [Tue] 334.3 22.3 -36.9
2003 May 14 [Wed] 331.6 22.3 -34.6
2003 May 15 [Thu] 328.9 22.3 -32.1

Klla: amsat

Per-ke SM4UVP frgar p mailinglistan:

Hej jag tnkte hra med er som r Qrv p AO40 om det r dliga frhllanden just nu fr att ev lyssna efter satelliten. Hur viktigt r det med den sk sqint vinkeln.
Och nr i s fall vet man att det r ngon ev ide att testa. Hlsningar SM4UVP Per-ke 73 73.

Hkan SM7SWJ svarar:

Vad jag hrt s r det sista bra lget p lrdag, sedan s r det 4 veckor tills satelliten ska vara krbar igen. Just nu s r det vl en sdan period som vi hade i hstas nr satellitens antenner vndes frn jorden. Framt sommaren s laddar vi fr fullt med ny 90cm parabol i masten och G3RUH patch.

73 Hkan SM7WSJ

ven Olle SM0DY svarar:

Bsta informationskllan betrffande AO-40 r AMSAT-DL:s hemsida http://www.amsat-dl.org .W4SM har en liten artikel skriven fr ngon dag sedan om hur Undanmanvern kommer att g till. Man slr av transpondern den 19 april 2350 UTC och har den avslagen i ca fyra veckor.

73 de SM0DY/Olle

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AO-40 is continuing to drift downward in ALON as predicted.

This is making the squint/range combination less favorable for passband use.

In addition, the solar angle is worsening and will shortly exceed 45 degs,limiting available power and warming the spacecraft considerably as the sun swings across the omni end of the spacecraft.

The AO-40 passbands will be turned off at MA=240 (23:50 UTC) on Saturday 4/19. They will remain off for about 4 weeks (or slightly less) until conditions improve.

– —W4SM for the AO-40 Command Team

Klla: amsat