Re: Satellite Modes

Dave AA6YQ

+ AA6YQ comments below

Something got stuck in my head a while back and I made a list:

S band is a problem because, by IEEE's naming, amateurs have two bands
- 13 and 9 cm.

My research shows that 6 mm was designated "R" (not Q) by AMSAT-DL in the run-up to the ill-fated OSCAR 40 while IEEE calls it V ... but of course AMSAT used V for 2 m. It's all good.

I do have the citation for AMSAT's band designators on the page above but if I have a copy of the document ... I've misplaced it! The title is listed, though.

The reason for this was because the original modes, A (2 up, 10 down), B (70 up, 2 down), J (2 up, 70 down) clearly wouldn't scale with the number of bands that OSCAR 40 (Phase 3D prior to launch) was to have and follow on spacecraft were expected to have. So, wisely, they went with a letter for each band and, as Suitbert notes, the first letter is the uplink, the second is the downlink.

Sadly, as is often the case, old timers couldn't let go and insisted on using the old single-letter modes leading to mixed messages in AMSAT publications.

I would suggest mapping the uplink and downlink bands entered by the operator to those bands' appropriate letter but allow the operator to override the default should they wish to use the obsolete designator.

+ If on startup the next version of DXKeeper finds a file named SatelliteModes.txt in its Databases folder, the Satellite Mode selectors are initialized from the satellite modes specified in this file, one line per mode; otherwise, the Satellite Mode selectors are loaded with a default set of Satellite Modes as provided in previous versions of DXKeeper, augmented by SX.


Dave, AA6YQ

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